The Present Threat to Coastal Cities From Antarctic and Greenland Melt

Seas around the world are rising now at a rate of about 3.3 milimeters per year. This rate of rise is faster than at any time in the last 2,800 years. It’s accelerating. And already the impacts are being felt in the world’s most vulnerable coastal regions.

(Rates of global sea level rise continue to quicken. This has resulted in worsening tidal flooding for coastal cities like Miami, Charleston, New Orleans and Virginia Beach. Image source: Ice Melt, Sea Level Rise, and Superstorms.)

Sea Level Rise and Worsening Extreme Rainfall are Already Causing Serious Problems

Last week, New Orleans saw pumps fail as a heavy thunderstorm inundated the city. This caused both serious concern and consternation among residents. Begging the question — if New Orleans pumps can’t handle the nascient variety of more powerful thunderstorms in the age of human-caused climate change, then what happens when a hurricane barrels in? The pumps, designed to handle 1.5 inch per hour rainfall amounts in the first hour and 1 inch per hour rainfall amounts thereafter were greatly over-matched when sections of the city received more than 2 inches of rainfall per hour over multiple hours.

Higher rates of precipitation from thunderstorms are becoming a more common event the world over as the hydrological cycle is amped up by the more than 1 degree Celsius of temperature increase that has already occurred since 1880. And when these heavy rainfall amounts hit coastal cities that are already facing rising seas, then pumps and drainage systems can be stressed well beyond their original design limits. The result, inevitably, is more flooding.

(Dr Eric Rignot, one of the world’s foremost glacial scientists, discusses the potential for multimeter sea level rise due to presently projected levels of warming in the range of 1.5 to 2 C by mid to late Century.)

New Orleans itself is already below sea level. And the land there is steadily subsiding into the Gulf of Mexico. Add sea level rise and worsening storms on top of that trend and the crisis New Orleans faces is greatly amplified.

All up and down the U.S. East and Gulf Coasts, climate change driven sea level rise and a weakening Gulf Stream are combining with other natural factors that can seriously amplify an ever-worsening trend toward more tidal flooding. It’s a situation that will continue to worsen as global rates of sea level rise keep ramping higher. And how fast seas rise will depend both on the amount of carbon that human beings ultimately dump into the Earth’s atmosphere and on how rapidly various glacial systems around the world respond to that insult (see discussion by Dr. Eric Rignot above).

Presently High and Rising Atmospheric Carbon Levels Imply Ultimately Catastrophic Sea Level Rise — How Soon? How Fast? Can We Mitigate Swiftly Enough to Prevent the Worst?

Presently, atmospheric carbon forcing is in the range of 490 parts per million CO2 equivalent. This heat forcing, using paleoclimate proxies from 5 to 30 million years ago, implies approximately 2 degrees Celsius of warming this Century and about 4 degrees Celsisus of warming long term. It also implies an ultimate sea level rise of between 60 and 180 feet over the long term. In other words, if atmospheric carbon levels are similar to those seen during the Miocene, then temperatures are also ultimately headed for those ranges. Soon to be followed by a similar range of sea level rise. In the nearer term, 1.5 to 2 C warming from the 2030s to late Century is enough to result in 20 to 30 feet of sea level rise.

Of course, various climate change mitigation actions could ultimately reduce that larger heat forcing and final related loss of glacial ice. But with carbon still accumulating in the atmosphere and with Trump and other politicians around the world seeking to slow or sabotage a transition away from fossil fuels, then it goes to follow that enacting such an aggressive mitigation will be very difficult to manage without an overwhelming resistance to such harmful policy stances.

(Antarctic ice loss through 2016. Video source: NASA.)

That said, warming and related sea level rise will tend to take some time to elapse. And the real question on many scientists’ minds is — how fast? Presently, we do see serious signs of glacial destabilization in both Greenland and West Antartica. These two very large piles of ice alone could contribute 34 feet of sea level rise if both were to melt entirely.

Meanwhile, East Antarctica has also recently shown some signs of movement toward glacial destabilization. Especially in the region of the Totten Glacier and the Cook Ice Shelf. But rates of progress toward glacial destabilization in these zones has, thus far, been slower than that seen in Greenland and West Antarctica. Present mass loss hot spots are in the area of the Thwaites Glacier of West Antarctica and around the western and southern margins of Greenland.

(Greenland ice loss through 2016. Video source: NASA.)

With global temperatures now exceeding 1 C and with these temperatures likely to exceed 1.5 C within the next two decades, it is certain that broader heat-based stresses to these various glacial systems will increase. And we are likely to see coincident melt rate acceleration as more glaciers become less stable. The result is that coastal flooding conditions will tend to follow a worsening trend — with the most vulnerable regions like the U.S. Gulf and East Coasts feeling the impact first. Unfortunately, there is risk that this trend will include the sudden acceleration of various glaciers into the ocean, which will coincide with rapid increases in global rates of sea level rise. In other words, the trend for sea level rise is less likely to be smooth and more likely to include a number of melt pulse spikes.

Such an overall trend including outlier risks paints a relatively rough picture for coastal city planners in the 1-3 decade timeframe. But on the multi-decade horizon there is a rising risk that sudden glacial destabilization — first in Greenland and West Antarctica and later in East Antarctica will put an increasing number of coastal cities permanently under water.

Rapid Mitigation Required to Reduce Risks

The only way to lower this risk is to rapidly reduce to zero the amount of carbon hitting the atmosphere from human sources while ultimately learning how to pull carbon out of the atmosphere. The present most rapid pathway for carbon emissions reductions involves an urgent build-out of renewable and non-carbon based energy systems to replace all fossil fuels with a focus on wind, solar, and electrical vehicle economies of scale and production chains. Added to various drives for sustainable cities and increasing efficiency, such a push could achieve an 80 percent or greater reduction in carbon emissions on the 2-3 decade timescale with net negative carbon emissions by mid Century. For cities on the coast, choosing whether or not to support such a set of actions is ultimately an existential one.

Links:

Fragmenting Prospects For Avoiding 2 C Warming

NASA Antarctic Ice Loss

Scientists Just Uncovered Another Troubling Fact About Antarctica’s Melting Ice

It Wasn’t Even a Hurricane, But Heavy Rains Flooded New Orleans as Pumps Faltered

Why Seas are Rising Faster in Miami

Miocene Relative Sea Level

Temperature on Planet Earth

Ice Melt, Sea Level Rise, and Superstorms

New Study Finds that Present CO2 Levels are Capable of Melting Large Portions of East and West Antarctica

If you’re a regular reader of this blog and its comments section, you’re probably more than a little worried about two bits of climate science in particular:

Our understanding of past climates (paleoclimate) and 5-6 C long term climate sensitivity.

And if you’re a frequent returner, you’ve probably figured out by now that the two go hand in glove.

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Looking back to a period of time called the Pliocene climate epoch of 2.6 to 5.3 million years ago, we find that atmospheric carbon dioxide levels were somewhat lower than they are at present — ranging from 390 to 400 parts per million. We also find that global temperatures were between 2 to 3 degrees Celsius warmer than 1880s ranges, that glaciers in Antarctica and Greenland were significantly reduced, and that sea levels were about 25 meters (82 feet) higher than they are today.

(The Totten Glacier is one of many Antarctic land ice systems that are under threat of melt due to human-forced warming. A new paleoclimate study has recently found that levels of atmospheric greenhouse gasses that are below those presently in our atmosphere caused substantial Antarctic melt 4.23 million years ago. Image source: antarctica.gov.)

Given that atmospheric CO2 levels during 2017 will average around 407 parts per million, given that these levels are above those when sea levels were considerably higher than today, and given that these levels of heat trapping gasses are rapidly rising due to continued fossil fuel burning, both the present level of greenhouse gasses in the Earth’s atmosphere and our understanding of past climates should give us substantial cause for concern.

This past week, even more fuel was thrown onto the fire as a paleoclimate-based model study led by Nick Golledge has found that under 400 parts per million CO2 heat forcing during the Pliocene, substantial portions of Antarctica melted over a rather brief period of decades and centuries.

Notably, the model found that the West Antarctic Ice Sheet collapsed in just 100-300 years under the steady 400 ppm CO2 forcing at 4.23 million years ago. In addition, the Wilkes Basin section of Antarctica collapsed within 1-2 thousand years under a similar heat forcing. In total, the study found that Antarctica contributed to 8.6 meters of sea level rise at the time due to the loss of these large formations of land ice.

From the study:

We conclude that the Antarctic ice sheet contributed 8.6 ± 2.8 m to global sea level at this time, under an atmospheric CO2concentration identical to present (400 ppm). Warmer-than-present ocean temperatures led to the collapse of West Antarctica over centuries, whereas higher air temperatures initiated surface melting in parts of East Antarctica that over one to two millennia led to lowering of the ice-sheet surface, flotation of grounded margins in some areas, and retreat of the ice sheet into the Wilkes Subglacial Basin. The results show that regional variations in climate, ice-sheet geometry, and topography produce long-term sea-level contributions that are non-linear with respect to the applied forcings, and which under certain conditions exhibit threshold behaviour associated with behavioural tipping points (emphasis added).

This study began the publication process in 2016 when year-end atmospheric CO2 averages hit around 405 parts per million. By end 2017, those averages will be in the range of 407 parts per million. Even more worrying is the fact that CO2 equivalent forcing from all the various greenhouse gasses that fossil fuel burning and related industrial activity has pumped into the atmosphere (methane, nitrogen oxides, CFCs and others) will, by end 2017 hit around 492 ppm.

As a result, though conditions in Antarctica are presently cooler than during 4.23 million years ago, the considerably higher atmospheric greenhouse gas loading implies that there’s quite a lot more warming in store for both Antarctica and the rest of the world. A warming that, even if atmospheric greenhouse gasses remain at present highly elevated levels and do not continue to rise, could bring about a substantially more significant and rapid melt than during the Pliocene.

Links:

Antarctic Climate and Ice Sheet Configuration During Early Pliocene Interglacial at 4.23 Ma

NOAA ESRL CO2 Trends

NOAA’s Greenhouse Gas Index

East Antarctic Ice Sheet More Vulnerable to Melting than We Thought

Pliocene Climate

antarctica.gov

Hat tip to Spike

100 Fossil Fuel Companies Responsible for 71 Percent of Carbon Emissions Since 1988 — And They’re Being Sued For it

According to research from the Carbon Disclosure Project, since 1988, 100 fossil fuel producers have been responsible for 635 billion tons of greenhouse gas emissions. This total represents 71 percent of human carbon emissions that have occurred over the past 29 years.

Companies involved in this massive carbon emission included such giants as ExxonMobil, Shell, BHP Billiton and Gazprom. The report also found that these 100 companies were responsible for fully 52 percent of all emissions since the industrial revolution began in 1751.

Report authors went on to point out that this relatively small group of companies is likely to have an outsized influence on responses to climate change — hopefully adding that positive action by such corporations could produce significant positive change. However, historically, such companies have tended to fight against global climate treaties, misinform the public on dangers related to human-caused climate change, and work to delay responses to climate change within their host nations. Due to this past bad-economic-actor behavior combined with rising climate change related damages, these corporations also are exposed to what may well be a historic and unprecedented corporate liability.

(If you were born in 2015, the estimate for your lifetime lost wealth from climate change, according to DEMOS, is between 581,000 and 764,000 dollars. With 100 companies responsible for 50 percent of that loss, it’s pretty obvious that liability will become a more and more serious impact as climate harms ramp up throughout the coming decades.)

A far-reaching liability that could well include various harms related to climate change coming from such diverse dangers as sea level rise, loss of water and food security, loss of habitability due to heat, and damage to valuable natural resources like forests, glaciers and reefs.

Already, a number of lawsuits are testing the legal waters in this regard. For example, in California this week, Imperial Beach, San Mateo and Marin counties are filing lawsuits to get some of the world’s largest fossil fuel producers to pay for sea level rise related damages. And if Imperial Beach and the two counties prevail, large corporations like Chevron, ExxonMobil, ConocoPhillips, BP and Royal Dutch Shell could be liable for billions of dollars in mitigation costs and punitive damages in coming decades even as direct damages from climate change ramp up.

According to the San Diego Union Tribune:

Attorneys for the plaintiffs said they modeled their legal tactics after past efforts to hold accountable cigarette businesses, makers of cancer-causing agents and gas and chemical companies that used methyl tertiary butyl ether (MTBE), a gasoline additive that has contaminated groundwater across the country.

And though not all liability related lawsuits against major tobacco and chemical companies were successful, those that stuck resulted in major awards even as the lawsuits themselves produced a very harmful public relations impact for the companies involved.

Antarctica’s 4th Largest Ice Shelf is About to Melt Back to its Smallest Area Ever Recorded

These days, there’s a big debate raging in the sciences over the issue of Antarctic melt. On the one side, you have a growing flood of data indicating that many ice shelves are thinning, that surface melt is more prevalent than previously thought, and that glaciers are threatening to destabilize at faster than previously expected rates. On the other side, we still have a number of hold-outs who rightly claim that ice shelves have always calved and that many of the processes we now observe have always been in place.

The scientific messengers sending these various indicators of Antarctic destabilization are cautious not to draw too many conclusions. But the data itself is pretty stark — which has been enough to produce some qualified, if very appropriate, warnings that Antarctica could be tipping toward instability far faster than previously imagined.

(The northern end of a massive rift in the Larsen C Ice Shelf is spawning numerous smaller ice bergs off a larger, Delaware-sized monstrosity. Now, only 3 miles of ice connect this emerging berg to the Larsen C ice mass. Once the berg separates, Larsen C will break back to its smallest area ever recorded. Image source: Project MIDAS.)

Of course the ice shelves named Larsen A and Larsen B existed throughout human times until they were only recently melted by warmth creeping up the along the Antarctic Peninsula in both the air and the water. Meanwhile, the Larsen C ice shelf is about to shatter off a very large 5,800 square kilometer ice berg even as several smaller ice bergs also appear ready to form. This event, which is now imminent in the coming days, weeks, or at most, months, will break the Larsen C ice shelf back to its smallest area ever recorded even as it marks a period of increased instability and risk of ice shelf loss.

For recent scientific assessments show that Larsen C is lowering in the water — an indication that the shelf is thinning. Furthermore, when the gigantic, Delaware-sized, ice berg and its smaller siblings break off they will take with them outer sections of a stabilizing compression arch. The compression arch, somewhat like the arch of a flying buttress, helps to balance structural stresses for the ice shelf. If it were to be compromised in total, according to glacier scientists like Dr. Eric Rignot, Larsen C would soon be adding its name to the list of various ice shelves around the world that have already fallen due to the warming airs and waters produced by human-caused climate change.

(The large ice berg that is presently breaking away from Larsen C appears to have bisected both southern and northern sections of the ice shelf’s stabilizing compression arch [indicated in the upper images by a solid gray line]. Loss of parts of the compression arch are an indication that Larsen C could become considerably less stable in the near future. However, some science indicates that the ice berg presently breaking off from Larsen C does not compromise key stability features. The nearer term future for the greatly reduced Larsen C Ice Shelf is therefore uncertain. Image source: Marine Ice Regulates Future Stability of Large Antarctic Ice Shelf.)

As with most predictive measures, however, the present trend isn’t perfectly clear with regards to the ultimate fate of Larsen C in the near future. Some studies have indicated that the section of ice breaking off is not crucial to the ice shelf’s stability. And the sections of the compression arch that are being taken out are closer to the outer edge of the ice shelf — not representing the key central arch region.

Overall, however, this story for Larsen C isn’t a good one. The shelf is thinning, it is about to reach its smallest area ever recorded, and even the loss of some outer sections of the compression arch are enough for a number scientists to express qualified concern. Larsen C didn’t show this level of instability back in the 90s or 2000s, so the overall trend here is more toward melt and instability for this 4th largest ice shelf in Antarctica.

UPDATE:

As of 7/10/2017 through 7/12/2017, rift formation had finally met open water and the large ice berg breaking away from Larsen C had finally calved. From the Project MIDAS website:

A one trillion tonne iceberg – one of the biggest ever recorded – has calved away from the Larsen C Ice Shelf in Antarctica. The calving occurred sometime between Monday 10th July and Wednesday 12th July 2017, when a 5,800 square km section of Larsen C finally broke away. The iceberg, which is likely to be named A68, weighs more than a trillion tonnes.  Its volume is twice that of Lake Erie, one of the Great Lakes.

Links:

Project MIDAS (and associated scientists)

Antarctica is About to Lose an Enormous Piece of Ice

Marine Ice Regulates Future Stability of a Large Antarctic Ice Shelf

Maximum Buttressing of Larsen C Ice Shelf

Antarctica’s Ice Shelves Thin — Threaten Significant Sea Level Rise

Scientific Hat tip to Dr. Eric Rignot

Scientific Hat tip to Dr. Richard Alley

A Delaware-Sized Iceberg is About to Enter the Southern Ocean — Loss of Larsen C Ice Shelf Possible in Near Future

A rift in West Antarctica’s Larsen C Ice Shelf is about to expel a 1,000 foot tall, Delaware-sized iceberg into the Southern Ocean. The crack began to form in 2011. But over the past year, it has expanded rapidly. Now this massive, newly-forming iceberg hangs by just a thin 13 kilometer wide thread.

As you can see from the above Sentinel 1 animation posted by Adrian Luckman, rift progression has occurred in large leaps as pressure on the shelf reached various breaking points. New additions to the rift have often been in jumps of 20 kilometers or more of rift length in numerous instances over the past year. With just 13 kilometers of connecting ice remaining, the entire state-sized iceberg could now break off at any time.

According to Project Midas, late June observations show the crack continuing to widen at the rate of about 2 meters per day. So the larger section of the newly-forming berg is progressing toward the Southern Ocean at a rather rapid rate. And this movement is increasing strain on the small remaining ice bridge to the larger Larsen C Shelf.

Once the massive berg breaks off, researchers are concerned that it could precipitate a larger collapse of the Larsen C Ice Shelf itself. Such an event would be the third ice shelf loss along the Antarctic Peninsula during recent decades. A series of ice shelf collapses precipitated by warming oceans and atmospheres induced primarily by fossil fuel burning.

(Many cities are already suffering from rising ocean levels. However, future rates of sea level rise can increase considerably over present rates depending on how rapidly glaciers and ice shelves are taken down by human-forced warming. Image source: Tamino.)

Such ice shelf losses are a rather serious affair as they release the glaciers behind them — allowing these massive ice forms to enter the world ocean more rapidly and thus increasing the rate of global sea level rise. Already, numerous cities, islands and nations are under threat from oceans presently rising at the rate of 3.3 millimeters per year globally. But loss of buttressing ice shelves like Larsen C and others around Antarctica and Greenland may double the present rate of rise many times over.

At a recent meeting of over 250 U.S. Mayors in Miami to discuss how climate change is presenting a serious threat to cities, New York’s Bill de Blasio told reporters: “Miami Beach is facing, literally, an existential crisis.” But it’s not just Miami that’s under the gun. It’s pretty much every coastal town, city, state and nation around the world. And Larsen C is just one of the most recent sea level rise canaries to begin to show signs of ailing in the global warming coal mine.

Links:

Project Midas

A New Crack in One of Antarctica’s Largest Ice Shelves Could Mean a Major Break is Near

Miami Beach Mayors Talk Global Warming

Tamino

Hat tip to Abel

Note: 1,000 foot tall reference includes freeboard + below water line measure.

Featured Comment:

Featured Comment Colin Wright

The Rains of Antarctica are Coming — Warm Summer Storms Melted Texas-Sized Section of Ross Ice Shelf Surface During 2016

“In West Antarctica, we have a tug-of-war going on between the influence of El Niños and the westerly winds, and it looks like the El Niños are winning. It’s a pattern that is emerging. And because we expect stronger, more frequent El Niños in the future with a warming climate, we can expect more major surface melt events in West Antarctica (emphasis added).” — David Bromwhich, co-author of a recent study identifying massive summer surface melt in West Antarctica during 2016.

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If you’re concerned about human-caused global warming, then you should also be concerned about ice. In particular — how warming might melt a miles-high pile of the frozen stuff covering the massive continent of Antarctica.

During recent years, scientists have become more and more worried as they’ve observed warming oceans eating away at the undersides of floating ice sheets. This particular process threatens numerous cities and coastal regions with swiftening sea level rise as ice margins melt and glaciers the size of mountain ranges clamor for release into the world’s oceans.

Major Antarctic Surface Melt Event During 2016

But another potential process in a still warmer world threatens to compound the impact of the heating waters that are already melting so many of the world’s glaciers from the bottom up — large scale surface melt.

(A major warming event during January of 2016 turned a Texas-sized section of Antarctica’s surface into slush. This occurred as a storm running in from the Southern Ocean delivered warm air and rainfall to sections of West Antarctica. Scientists are concerned that more major surface melt is on the way for Antarctica as the Earth’s climate heats up and that repeated warming and rainfall events in this typically-frozen region may further quicken rates of sea level rise. Image source: Earth Nullschool.)

During January of 2016, as a very strong El Nino was combining with human-caused global warming to spike atmospheric temperatures to 1.2 C above 1880s levels, something pretty strange and concerning happened. Over the course of about 15 days, a 300,000 square mile section of the Ross Ice Shelf surface and nearby lands over West Antarctica experienced melting. This mass slushing across Antarctica’s surface occurred as a warm storm swept in from the Southern Ocean (see image above) to deliver an unheard of rainfall event to the region.

West Antarctica is typically too cold for such weather. It is also often too dry. The region is well know by climate researchers as a frozen desert. But as human-forced climate change has warmed the nearby ocean, warm, moist winds blowing in from these heating waters have become more frequent.

Westerlies Interrupted by Warming Ocean

Antarctica is typically protected by strong westerly winds that keep both heat and moisture out. But a warming ocean environment, according to Ohio State researchers, is enabling El Nino to interrupt these westerlies and hurl increasing volumes of heat and moisture over the glaciers of Antarctica. In 2016, countervailing winds pushing against the typically prevailing westerlies bore with them an odd rainstorm that set off a massive surface melt event.

(Surface melt over a large section of West Antarctica lasted for as much as 15 days as heat and moisture from the surrounding ocean beat back a protective barrier of westerly winds and invaded the frozen continent. According to scientists, these events are likely to become more frequent and long-lasting as the climate warms. Image source: Ohio State University.)

When combined with already-active melt from ocean warming, surface melt could further serve to destabilize ice sheets and swiften sea level rise. This was exactly the concern that David Bromwich, an Antarctic researcher at Ohio State and co-author of the paper that identified this strange event highlighted in this statement (please see related Washington Post article here):

“It provides us with a possible glimpse of the future. You probably have read these analyses of West Antarctica, many people think it’s slowly disintegrating right now, and it’s mostly thought to be from the warm water eating away at the bottom of critical ice shelves. Well, that’s today. In the future, we could see action at the surface of these ice shelves as well from surface melting. So that makes them potentially much more unstable (emphasis added).”

It’s worth noting that this particular storm, though unusual and noteworthy, did not produce too much in the way of surface melt ponding. Instead, the storm turned a large section of the Antarctic surface to a slurpee-like slush. But this event did deliver a considerable amount of heat to the Ross Ice Shelf region. And repeated instances could serve to seriously soften this massive ice formation.

Eventually, as warming worsens, significant surface melt and flooding could help to shatter large buttressing ice shelves like Ross or even generate risks of surface glacial outburst flooding in instances where permanent surface melt lakes form behind an ice dam. But the primary concern at this time is that these warm rain events provide a compounding melt influence that adds to risks for more rapid sea level rise this Century.

Links:

Widespread Snowmelt in Antarctica During Unusually Warm Summer

Scientists Stunned by Antarctic Rainfall and Melt Area Bigger Than Texas

Scientists Report Large Scale Surface Melting Event in Antarctica During 2015-2016 El Nino

The Ross Ice Shelf

Earth Nullschool

Hat tip to TodaysGuestIs

New Crack Found in Delaware-Sized Chunk of Larsen C Ice Shelf as it Heads Toward Southern Ocean

A 2,000 square mile section of the Larsen C Ice Shelf is hanging by a thread as it continues to drift toward the Weddell Sea.

(A second crack develops in Larsen C Ice Shelf. Image source: Project MIDAS.)

The break-off section represents fully 10 percent of all the ice contained in the Larsen C system. It has been divided from the larger ice shelf by a 180 kilometer long crack that began to develop in 2009 and that swiftly lengthened during recent years. Now only a 10 kilometer wide bridge links the breaking section to the larger ice shelf. And considering the enormous stresses now being placed on this break-off section it is expected to go at any time.

Since January, according to researchers at Project MIDAS, the large crack has been widening but its length growth has stalled. However, recent reports out this week from MIDAS found that a new crack had developed at the ice-bridge end of the break-off section. The new crack appears to be rounding the corner of the bridge to begin a quicker path to segmenting the massive ice berg away from Larsen C. A testament to the powerful forces that are inevitably forcing this enormous section of ice to relinquish its hold.

(Large section of Larsen C is moving far faster than the rest of the ice shelf toward the Southern Ocean. Image source: Project MIDAS.)

At issue is the fact that the break-off section is moving toward the Weddell Sea considerably faster than the rest of the Larsen C ice shelf. Much of this large section of ice is proceeding away from the Antarctic mainland at 3 meters per day. Surrounding sections of Larsen C are moving at only 1-2 meters per day. As a result, the toe end of the break-off mass is tipping out into Weddell’s waters and the crack separating it from Larsen C is widening.

It’s not really a question of if this massive block of ice will separate from Larsen C. More an issue of how soon.

Loss of so large a section of ice from Larsen C threatens the entire ice shelf’s stability. And some scientists are questioning whether the whole ice shelf will destabilize and eventually splinter — as happened to Larsen A and Larsen B during recent years.

(Rapid loss of buttressing ice shelves like Larsen C lock in higher and higher ranges for sea level rise. A worrying risk for rapid sea level rise occurs as global temperatures warm to between 1.5 and 2.5 C. A level we are fast approaching. Scientists like James Hansen identify a significant risk for multi-meter sea level rise this Century if 2 C warming thresholds are breached. Video Source: Carbon Freeze.)

Warming ocean waters due to human-forced climate change are the primary driver for loss of ice shelves around the world. These ice shelves hold back land glaciers — preventing them from more rapidly sliding into the world’s oceans. Larsen C alone holds back glaciers capable of lifting global ocean levels by 4 inches. But there are numerous such ice shelves and many are now facing thinning and increasing instability due to warming ocean waters. As a result, a growing number of scientists are concerned about the possibility for multi-meter sea level rise this Century if fossil fuel burning is not swiftly halted.

Links:

Project MIDAS

Carbon Freeze

Second Giant Crack Appears on Larsen C

Crack in Larsen C Forks

Larsen C Destabilization Could Trigger 4 Inch Sea Level Rise

Hat tip to June

Hat tip to Andy in San Diego

In Defense of Our Earth — A People’s Climate March

I think it can be fairly said that we are a people who believe in a better future. That the ideals of America are founded on building prosperity and expanding prospects — not only for ourselves, but for our fellows and for those generations that are to follow.

Americans have often been described as a ‘can-do’ kind of people. A people who will undertake any challenge to advance or protect our nation and to graciously extend her kind virtues to the huddled masses of a troubled world. Be it the freeing of slaves, the emancipation of women, the facing down of tyrannical dictators, the liberation of scientific inquiry, or the exploration of our Earth and the vast realm of space we have doggedly decided to march forward and on.

But today we are confronted by a new trouble. A trouble that was, in many ways, an unintended consequence of past progress. For as we industrialized, as a nation and as a global society, we also burned ancient carbon deposits long buried beneath the Earth. And so we expelled a great cloud of the most dangerous of gasses into the Earth’s atmosphere.

We didn’t know it so well at the time. But the carbon dioxide spewing from William Blake’s dark Satanic Mills was the same gas that in excess produced the worst and most horrific global die-offs in the great and deep, deep history of our Earth. Times of great mass extinction due to rising global heat that bear the infamous names — Permian, Triassic, Paleocene, Devonian and Ordovician. Blake, living today, would be terrified how right he was to call those mills Satanic. To learn what our scientists now have told us. But even then, he surely had an inkling. For the Bible itself warns — those who destroy the Earth shall be destroyed. And in 1808 the wanton destruction of the Earth and its airs by the pollution caused by fossil fuel burning was visibly evident if not so scientifically proven and explored as it is today.

Today, if we continue to burn fossil fuels as we have for the past 200 years or so, the world will again surely experience another such extinction. We already see the outliers of this crisis now — in the growing number of people bereft of land and home and livelihood as seas rose, or crops were destroyed by worsening storms and droughts, or lands and animals were lost to wildfires, or as reefs and fisheries were killed off by the warming, acidifying waters of our oceans. But what will come over the years and decades and centuries if we do not turn back from this horrid burning of fossil fuels and the dumping of their carbon into the atmosphere will be far, far worse.

What kind of world is this to make for our fellow human beings? What kind of future to leave for the generations that follow? Surely not the better one that we all work and hope for. Surely not one that honors the can-do, make the world a better place spirit of America.

But despite our worsening prospects and the dark and heavy clouds that now hang over the global climate, we have a window of opportunity in which to act. Our tools to confront climate change in the form of renewable energy systems like wind and solar and electrified transportation are growing more capable. And further innovation and change in our actions as people and nations can yet enable us to draw down the awful pall of heat trapping gasses that now hangs above us. These are things we can and must do if we are a moral people with any kind of vision, foresight and compassion.

This is our moment. The moment when we decide to make the choice to act and to save so many of the very precious things we all hold dear or to turn away from action and condemn each and every person and being now living or that will live to an age of terror and darkness the likes of which Earth has not seen in all of half a billion years.

So I’m asking you for your help. I’m asking you to make the choice to act. To join the People in their march for climate justice tomorrow. To support all the voices that are now speaking out. To lift your own voice to our growing chorus.

For the love of life and of all good things — we simply must act now.

Antarctica is About to Lose a 2,000 Square Mile Chunk of Ice — And it Could Mean the End of the Larsen C Ice Shelf

It’s happened before. Ice shelves on the northern Antarctic Peninsula released large chunks of ice into the Southern Ocean as the world warmed up. They developed a concave shape which became unstable. Then they collapsed.

The ultimate collapse of Larsen A occurred in 1995. In 2002, further up the Antarctic Peninsula, the larger Larsen B Ice Shelf succumbed to the same fate. And it is thought that such losses haven’t happened to this section of Antarctica in at least 11,000 years and possibly as long ago as 100,000 years.

(NASA’s Jet Propulsion Laboratory provides this narrative describing the collapse of the Larsen B Ice Shelf in 2002. Video source: JPL.)

But in the present world, one where human fossil fuel emissions have forced global temperatures above 1 C hotter than 1880s averages, the stability of many of the great great ice shelves is now endangered.

Larsen C Ice Shelf to Calve 2,000 Square Mile Ice Berg

Today, a huge rift has nearly bisected a large frontal section of the Larsen C Ice shelf — an ice system many times the size of its now deceased companions Larsen A and Larsen B. And during December — a period when Antarctica was warming into Austral Summer — this massive crack grew by 18 kilometers.

When, and not if, the crack reaches the ocean, a 2,000 square mile ice berg will float away from Larsen C. It will be one of the largest ice bergs ever to form in human memory. One the size of the state of Delaware. It will tower hundreds of feet above the ocean surface. And it will last for years before ultimately melting.

larsen-c-ice-rift-length-and-width

(The Larsen C is rift grew considerably — both lengthening and widening during December of 2016. It was an indication that a massive ice berg was about to break off. Image source: MIDAS.)

This event will change the geography of our world. And for this alteration alone, it has great consequence. But, as Chris Mooney notes in this excellent Washington Post article on the subject, it’s what happens afterward that really counts.

Event Could Presage Total Collapse

Of concern is the fact that once this massive ice berg calves off of Larsen C, the great ice sheet may become unstable. It will take on a concave form. This form will make it more vulnerable to further melt by warming waters running in toward the shelf. Furthermore, the large ice berg will take a chunk of Larsen C’s compressive arch with it. Such a compressive arch — like the arch of a flying buttress — helps to bear the weight of the shelf and keep it from smashing into thousands of tiny pieces. If too much of the arc is lost, the shelf can’t survive for long.

larsen-c-ice-rift-midas

(Researchers at The MIDAS Project have projected that a 2,000 square mile section of the Larsen C Ice Shelf is about to break off. This section represents 10 percent of the Larsen C system. Its loss risks destabilization of the entire ice shelf. If Larsen C does disintegrate, it will release glaciers capable of increasing global sea level by another 4 inches. Image source: MIDAS.)

Glaciologist Eric Rignot notes in The Washington Post:

“We studied the current rift in the past few years, it has been progressing rather ‘normally,’ the recent acceleration in the rift progression is ‘expected’ in my opinion. The consequences on the rest of the ice shelf are not clear at this point. If the calving continues and goes past the compressive arch … then the ice shelf will break up.”

Scientists are currently divided over the issue of whether or not Larsen C’s near-term demise is imminent. However, the loss of such a massive ice berg from Larsen C, the present human-forced warming of the Antarctic land and ocean environment, and the presently observed thinning of the ice shelf all point toward a rising risk of destabilization or disintegration.

As with most things geological, you can’t really say that such an event is certain until after the fact. But as for Larsen C’s prospects of long term survival, things aren’t looking too great at the moment.

Links/Credits

The MIDAS Project

Antarctica is Set to Lose an Enormous Piece of Ice

An Ice Berg the Size of Delaware is About to Break off From Antarctica

NASA’s Jet Propulsion Laboratory

A Flood of Warm Water the Size of 30 Amazon Rivers is Melting One of East Antarctica’s Largest Glaciers

If we’ve learned anything this year, it’s that few of Antarctica’s submerged coastal glaciers are safe from the warming ocean. Places that we once thought wouldn’t be vulnerable to melt for decades or centuries are now starting to feel the heat of rising water temperatures.

The heat comes in the form of great floods of warmer than normal waters running beneath the ocean surface and then eating away at the undersides of ice shelves and sea fronting glaciers. These floods are provided by the warmth forced into the world ocean by rising global greenhouse gas concentrations. And such invasions are happening around Antarctica’s perimeter with increasing frequency. But perhaps the most disturbing such event now ongoing is the present warm water flood running in from the Southern Ocean toward East Antarctica’s Totten Glacier.

calving-front-of-the-totten-glacier

(The melting edge of the Totten Glacier. Image source: Antarctica.gov.)

Totten is a truly gigantic glacier. By itself representing an ice mass equal to that contained in all of West Antarctica’s many glaciers. If large sections of Totten and the associated Aurora Basin were to melt, seas could rise by 12 feet or more. During recent years, researchers identified a great canyon running between 2,000 and 3,600 feet below sea level and stretching six miles wide as a weak point for Totten — whose glaciers sit in an enormous, below sea level rift within East Antarctica.

Researchers recently found that the floating ice shelf buttressing Totten was melting from below. As of 2015, they hadn’t identified a mechanism for this melt. But they had a pretty short suspect list. This year, a new study led by Dr. Stephen Rich Rintoul found that a river of warm water flowing at a rate of 220,000 cubic meters per second was flooding into the vulnerable canyon entrance to Totten’s weak underbelly. The researchers determined that this volume of warm water — equaling a flow rate more than 30 times that of the Amazon River — was enough to account for the observed ice shelf losses over recent years in the range of 60 to 80 billion tons per year.

totten-glacier-basin

(The Totten Glacier of East Antarctica contains about as much ice mass as all of West Antarctica. Its catchment basin is roughly the size of the U.S. Southeast. Much of it sits below sea level. And an ice shelf buttressing the glacier’s largest outlet in a 6 mile wide and 3,600 foot deep canyon is rapidly melting. Once this ice shelf breaks apart, ocean water will flood inland along a reverse slope and the Totten Glacier will increase its rate of movement toward the ocean — significantly speeding rates of global sea level rise. Image source: Australian Antarctic Division.)

The study authors found that:

…several lines of evidence support the conclusion that rapid basal melt of the [Totten Ice Shelf] is driven by the flux of warm [modified circumpolar deep water] into the cavity: the presence of warm water at the ice front, the existence of a deep trough providing access of this warm water to the cavity, direct measurements of mass and heat transport into the cavity, the signature of glacial meltwater in the outflow, and exchange rates inferred from the heat budget and satellite-derived basal melt rates.

Presently, because the ice shelf floats, this melt is not adding to global sea level rise. But the shelf acts like a cork that’s stopping the rest of Totten from flowing into the ocean. And when the ice shelf weakens enough, it will rift and break apart — leaving the massive glaciers behind it exposed to the inrush of warm waters and removing the last major barrier preventing them from bursting out.

Links:

Ocean Heat Drives Rapid Basal Melt of Totten Ice Shelf

Scientists Confirm that Warm Ocean Water is Melting one of East Antarctica’s Biggest Glaciers

One by One, the Flood Gates of Antarctica are Breaking Open

Tottering Totten and the Coming Multi-meter Sea Level Rise

Antarctica.gov

Hat tip to Robert in New Orleans

One By One, the Flood Gates of Antarctica are Breaking Open

“We have still time to avoid the worst of it, but we have already opened a number of flood gates, one in West Antarctica, and several in Greenland.”Dr Eric Rignot.

“This kind of rifting behavior provides another mechanism for rapid retreat of these glaciers, adding to the probability that we may see significant collapse of West Antarctica in our lifetimes.” Ian Howat, Earth Sciences associate Professor at Ohio State University.

“Burning all the world’s coal, oil and gas would melt the entire Antarctic ice-sheet and cause the oceans to rise by over 50m, a transformation unprecedented in human history. The conclusion of a new scientific study shows that, over the course of centuries, land currently inhabited by a billion people would be lost below water.” — The Guardian.

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Massive Rift Forming in Larsen C

Larsen C. It’s the next big ice shelf on the butcher’s block in West Antarctica. And now it appears the shelf may be well on its way to facing the same fate as its companions Larsen A and Larsen B. That fate — disintegration and the ultimate release of glaciers that have been held in check for thousands of years into the world ocean.

It was only about 150 years ago that the Larsen Ice shelves were discovered. And the Larsen shelf system is thought to have been mostly stable throughout the last 12,000 years. But in 1995 Larsen A splintered into a million icebergs. And in 2002 the larger portion of Larsen B broke apart. Warming Ocean waters heated by an atmosphere loaded with greenhouse gasses did the damage. And now the same warm water currents that shattered Larsen A and Larsen B are endangering their larger cousin — Larsen C.

larsen-c-ice-rift

(Ice shelves and sea fronting glaciers serve as the flood gates keeping West Antarctica’s glaciers from spilling into the ocean and raising sea levels by as much as 20 feet. But warm ocean waters are causing these flood gates to melt and crack wide open. The above image shows a massive abyssal rift forming in the Larsen C ice shelf. A similar rift formed in the center of the Pine Island Glacier last year. A signal that the West Antarctic Ice Sheet could undergo a major collapse over the next 100 years. Image source: NASA.)

For today, a huge rift running through the ice shelf is about to break off a Delaware-sized iceberg into the Atlantic Ocean. The rift is broadening, deepening and extending. And it now measures 70 miles long, 300 feet wide, and a third of a mile deep. Once this enormous abyssal crack runs its course and causes about 10 percent of the ice shelf to break off, the big land-grounded glaciers sitting upon mountainous slopes behind the ice shelf will have less protection. They will increase their forward speed and contribute larger volumes of ice outflow to the growing problem of global sea level rise.

In this way, rifts in Antarctica’s sea fronting glaciers and ice shelves can be seen as giant cracks in the flood gates holding back enormous glaciers that, when released, will lift global sea levels by feet and meters.

Big Crack in the Pine Island Glacier

Closer to the center mass of West Antarctica, the Pine Island Glacier serves as one of the most important of these flood gates. In total, the large grounded glaciers in what could best be termed as an ice bottle neck hold back about 10 percent of all of West Antarctica’s interior ice mass. But just last year a huge rift that formed in this glacial buttress during 2013 cracked wide open — causing three massive icebergs totalling ten times the size of Manhattan to break off.

According to a new study, warm ocean water flooded far inland along the underside of the Pine Island Glacier. It ate away at its base and then spilled down-slope to cut out a melting hollow in the glacier’s heart. Ultimately, an enormous crack formed within the glacier 20 miles away from where the ice mass meets the ocean at the surface.

(Massive crack forms in the Pine Island Glacier, then causes three very large icebergs to break off during 2015. A new study finds that the Pine Island Glacier is melting from the inside out and an inland flood of warm ocean water is causing both the melt and the formation of large rifts in the ice. Scientists believe that these could be the first signs of a significant collapse of West Antarctica that could occur without our lifetimes. Video source: Ohio State.)

Then, in 2015, gigantic chunks of ice covering 225 square miles broke off from the Glacier and floated out into the Amundsen Sea. This was the second series of icebergs to break off from the Pine Island Glacier in as many years. And scientists were notably very concerned.

Pine Island Glacier is particularly vulnerable because it sits on a reverse slope. In other words, a below sea level bed slopes lower as you progress toward the center of the Continent. And, in fact, large portions of West Antarctica are below sea level (see topographic image below).

Pine Island Glacier itself rests upon an opening to one of the deepest valleys sloping inland. At the location of the Pine Island glacier a rift between 500 and 2,000 feet below sea level runs down toward a central region of West Antarctica that sits between 2,000 and 6,000 feet below sea level. And within this basin is a pile of glacial ice that from bedrock to its highest point above sea level towers two and a half miles high. The very valid concern for this glacier is that melt and rifting, once started, will tend to accelerate — taking out larger and larger chunks of the inland ice as it is exposed to the warming ocean and heating atmosphere.

The Larger Picture — Glacial Flood Gates are Cracking Open

Larsen C and Pine Island Glacier serve as but two of the many flood gates that run all along the coast of West Antarctica and East Antarctica. But the increasing flows of warm water coming in from the ocean and a related rise in the frequency of events where large masses of ice break off from buttressing glaciers and ice shelves has put West Antarctica in danger of facing a near term collapse.

west-antarctica-below-sea-level

(Islands encased in ice. Much West Antarctica, on the left side of this topographic image, sits between 0 to 6,000 feet below sea level. If the buttressing glaciers and ice shelves like Larsen C and Pine Island are lost, there is little to prevent the warming oceans from flooding inland and setting off a rapid cascade of melt and seaward outflow. Scientists now believe that such a collapse could happen within our lifetimes. Image source: Antarctic Bedrock.)

With information from new glacial stability assessments in hand, Antarctic ice specialists are warning that the western region of this frozen land may collapse in a major melt event that over the next 100 years could raise sea levels by 10 feet. And West Antarctica is but one of three global regions — including Greenland and East Antarctica — capable of contributing significant glacial outbursts during this period.

Links:

West Antarctica Ice Shelf is Melting From the Inside Out

With a Collapsing West Antarctica, Sea Levels Could Rise Twice as High as We Thought

Combustion of Available Fossil Fuel Reserves Sufficient to Eliminate Antarctic Ice Sheet

Burning all Fossil Fuels Will Melt Entire Antarctic Ice Sheet

Rift in Antarctica’s Larsen C Ice Shelf

The Larsen Ice Shelves

NASA Captures Disturbing Images of Antarctica Ice Rift

Antarctic Bedrock

Pine Island Glacier Topography

Hat tip to Colorado Bob

Hat tip to ClimateHawk

Florida’s Existential Choice For 2016 — Renewables and Climate Responses or Death by Fossil Fuels

People living in the state of Florida have a big problem — their homeland, as it is today, cannot exist for very long if we double down on fossil fuel burning as Donald Trump has proposed. And this situation, in turn, creates a big problem for Trump — he can’t win the 2016 election without Florida’s support. Trump’s vicious combination of climate change denial, anti-renewables policy stances, and attacks on immigrants whose family members may also be displaced by climate change have considerably damaged his chances of capturing the state’s 29 electoral votes. He’s now in a situation where he’s basically reliant on smoke screens and misinformation to convince the voters of Florida to commit what amounts to an electoral suicide.

us-coal-production

(U.S. coal production has been falling since Obama’s election in 2008. As a result, US carbon emissions have plateaued. The kinds of renewable energy that the American people want can continue to generate reductions in greenhouse gasses flooding the environment and give the people living in Florida a fighting chance. But that won’t happen if we elect Donald Trump as President. Image source: Vox and The Energy Information Administration.)

Trump’s Dirty Energy Pledges Would Mean Certain Devastation For Florida

About a week ago, Trump pledged to, in effect, zero out all spending on renewable energy and climate change related science while pushing hard for an expansion of coal, oil, and gas burning if he is elected. Meanwhile, Trump’s energy team is little more than a covey of climate change deniers hand picked directly from the fossil fuel industry. Trump has pledged to kill the EPA, to roll back Obama’s Clean Power Plan, and to drop out of U.S. emissions reductions pledges to the Paris Climate Summit (COP 21).

If you were looking for an example of a perfect storm of the absolute worst climate change and renewable energy related policies, policies that were guaranteed to put the world back on a track toward a devastating business as usual carbon emission — then Trump fits the bill. And to large parts of Florida, Trump’s policy pledges are starting to look a lot like a promise to inflict climate Armageddon on the low-lying state.

(This year, surface melt was observed for the first time in East Antarctica. This new observation points to increased risk of glacial melt from a region that is capable of dramatically raising global sea levels. The people living in low-lying Florida are becoming more and more concerned. And they should be. Video source: Climate State.)

Miami-Dade County sits on the front lines of this rising climate crisis. Already, the city has pledged 400 million dollars to raise streets and upgrade the city’s drainage system. Why? The oceans in Miami have now risen to the point that tides frequently disrupt transportation, flood neighborhoods, and swamp businesses. These upgrades may buy Miami a decade or two or three. But there’s absolutely no way Miami can survive for any longer than this if Trump commits to his policy choices as-is. Even the rosiest rational predictions for sea level rise by the end of this Century put Miami mostly under water well before the year 2100 under the kinds of emission scenarios that a Trump Presidency would commit us to.

Further up the coast, Jacksonville is still reeling from damages inflicted by Hurricane Matthew — a storm made worse both by the record hot Atlantic Ocean and by the added effect sea level rise had on the height of its wind-driven surge of flooding water. Like Miami, Jacksonville is starting to feel the effects of sea level rise. And its likelihood for continued existence this Century would be quite low if Trump’s fossil fuel burning policies were enacted. The story is much the same for pretty much all of Florida’s coastal cities as well as the southern tip of Florida stretching on north to the Everglades. Sea level rise is an existential threat to these regions now. One that will be made far worse if we continue to burn the fossil fuels that Trump is committed to.

Trump Seeks to Kill Renewables While Amendment 1 Attempts to Stymie Solar

Even as Trump is moving to crush renewable energy progress and responses to climate change at the federal level, hurting Florida’s chances of facing down climate threats, the fossil fuel industry and a number of aligned utilities are attempting to stymie solar energy development across the state. Like much of America, residents within Florida are attracted by renewable energy. In fact, a recent poll showed that four out of five voters supported increasing levels of renewable energy development. Home and business owners alike want access to new, clean, independent energy choices. People rightly concerned about the impacts of climate change want more clean energy.

clean-energy-costs

(As the effects of climate change worsened, clean energy costs have been falling. Now costs are so low that financial benefits to individual energy users abound. Fossil fuel industry is acting in increasingly aggressive ways to stifle access by using laws to prevent people from using clean energy sources. Trump is fighting to help these corporations prevent you and your family members from taking advantage of the multiple benefits clean energy provides. Image source: The Whitehouse.)

Since renewable energy is so popular among voters, and even among republicans, fossil fuel special interests often resort to deceptive tactics in order to keep people captive to harmful energy consumption. And this election, utilities have attempted to protect their monopoly power interests by forcing anti-solar Amendment 1 on the state. Amendment 1 aims to open a loop-hole for utilities to charge independent renewable power generators exorbitant fees and to suppress the rate of solar adoption in the state. Amendment 1’s language has been called deceitful by the Union of Concerned Scientists. It’s a proposal that has been put forward by a collection of fossil fuel special interests including Exxon Mobile, Duke Power, The Koch Brothers, Florida Power and Light and others. And if the Amendment passes, it will help to lock Florida in a fossil fueled climate change nightmare. One that is, even now, starting to nibble away at the vital cities that enable the state to function.

Yuge Wave of Climate/Renewable Energy Voters?

With both the future existence of Florida’s cities and access to renewable energy under threat, voters in Florida are turning out like never before. Nationalized Hispanic and Caribbean immigrants whose families may also be forced to seek refuge in the U.S. due to climate change are voting in droves. And the people of the increasingly swamped Miami Dade County are flooding the polls. There, fully 55 percent of registered voters had cast a ballot before election day.

The record turnout in places like Miami-Dade helped bouy the Florida early vote to 6.4 million — more than the total post election day count for the year 2000. This large turnout has come as registered democratic voters lead republicans by 92,000 coming into election day. But first and second generation citizens may well be generating even more of a democratic edge. According to Vice, 86.9 percent more Latinos voted early than during 2012. And a good portion of that 455,000 total are registered as independents and even republicans. Meanwhile, there is some indication that well less than 90 percent of republicans are voting for Trump.

While Trump’s anti-immigrant rhetoric may have helped to generate some of this shift, it is likely that rising climate and energy concerns are also affecting the Florida vote. A poll from earlier this year found that concerns about climate change from Florida residents was on the rise. Fully 81.3 percent of Florida peninsular residents expressed moderate to serious concern about climate change as an issue. And though debate moderators and their mainstream media sponsors failed to raise the critical issues of climate change and renewable energy in the televised match-ups between Clinton and Trump, Clinton frequently harangued Trump for his noted extreme degree of climate change denial. Furthermore, Trump’s own statements and policy choices have produced enough ripples in the media to generate a general understanding that Trump is fighting against popular advances in renewable energy while stifling responses to climate change in a state where people are becoming increasingly aware that they’re under the gun. Together, these underlying political forces are likely to sap voters away from Trump in a state he must win to secure the 2016 election.

Let’s hope that happens. The future of Florida and so many other important things hangs in the balance.

Links:

Vox

The Energy Information Administration

Trump to Zero Out Clean Energy Funding

Climate State

U.S. Voters Want Renewable Energy

The Whitehouse

Four Reasons to Vote No on Anti-Solar Amendment 1

Florida Early Vote Beats Entire 2000 Turnout

Floridians are More Concerned About Climate Change

Half a Kilometer of Ice Gone in Just 7 Years — West Antarctica’s Smith Glacier Points To Nightmare Melt Scenario

The nightmare global warming melt scenario for West Antarctica goes something like this —

First, ocean waters warmed by climate change approach the vast frozen continent. Melt already running out from the continent forms a fresh water lens that pushes these warmer waters toward the ocean bottom. The waters then get caught up in currents surrounding Antarctica that draw them in toward numerous submerged glacial faces. The added ocean heat combines with falling melting points at depth to produce rapid melt along sea fronting glacier bases. Since many of these glaciers sit on below sea level beds that slope downward toward the interior of Antarctica, a small amount of initial melt sets off an inland flood of these warmer waters that then produces a cascade of melt. This glacial melt chain reaction ultimately generates a Heinrich Event in which armadas of icebergs burst out from Antarctica — forcing global sea levels to rapidly rise.

This is Why We Worry So Much About Multi-Meter Sea Level Rise

Ultimately, seas rising by multiple meters this Century are a very real possibility under current warming scenarios in which such a series of cascading melt events occurs in West Antarctica.

(NASA video narrated by Dr. Eric Rignot, a prominent glacial scientist. Concerns about the origin of melt water pulse 1A during the end of the last ice age led to investigation of large Antarctic melt pulses as a potential source. Subsequent investigation identified melt vulnerabilities at the bases of large sea fronting glaciers in West Antarctica to present and predicted levels of ocean warming. At issue was the fact that bottom waters were warming and that because many glaciers rested on sea beds that sloped inland, melt rates had the potential to very rapidly accelerate.)

Though such a nightmare melt scenario was recently theoretical, it represented a very real potential near-future event as global temperatures rose into the 1-2 degrees Celsius above 1880s range during recent years. For times in the geological past around 115,000 years ago also produced large glacial melt pulses and related sea level rises of 15-25 feet during periods of similar warmth.

However, direct evidence of such a powerful melt dynamic had not yet been directly observed in Antarctica’s glaciers. Fresh water lenses were developing, rates of glacial loss were quickening. Basal melt rates looked bad. But the kind of tremendous losses necessary to produce rapid sea level rise were not yet fully in evidence.

Smith Glacier Loses Half a Kilometer of Ice in Seven Years

That situation changed during recent weeks when two scientific papers broke the news that some of West Antarctica’s glaciers had lost upwards of a half a kilometer of ice thickness due to contact with warm ocean waters over the past decade.

The studies, entitled Rapid Submarine Ice Melting in the Grounding Zones of Ice Shelves in West Antarctica and Grounding Line Retreat of Pope, Smith and Kohler Glaciers took a comprehensive look at both surface and underside melt of three major west Antarctic glaciers near the Thwaites and Pine Island Glacier systems. These glaciers included Pope, Smith and Kohler — which have seen increasing instability and rates of seaward movement during recent years. Using multiple instruments, the scientists found evidence of massive ice losses and speeding ice flows.

pope-smith-and-kholer-glacial-flow-velocities

(Surface velocity of Kohler, Smith and Pope Glaciers provided by NASA. More rapid seaward movement of glaciers = faster rates of sea level rise.)

The losses occurred at a time when an influx of warmer water (warming circumpolar deep water) was heating the ice shelves and grounding lines buttressing these three partially submerged glaciers. This warming was found to have produced melt along the grounding zones of these glaciers in the range of 300 to 490 meters from 2002 to 2009. In other words, about 1/3 to 1/2 a kilometer of ice thickness at the grounding line was lost in just seven years. Melted away from below by warming deep ocean conditions at the rate of up to 70 meters or around 230 feet per annum.

The studies found that the Pope and Kohler glaciers, which rested on up-sloping sea beds, produced slower rates of melt. While Smith, which sat on a retrograde (or down-sloping bed) produced very rapid rates of melt. According to the Nature study:

We attribute the different evolution of Smith Glacier to the retreat of its grounding line deeper allowing warmer waters to flood its grounding zone, and increasing ocean thermal forcing due to the lowering of the in situ melting point; as well as to the exposure of the glacier bottom to ocean water as the grounding line retreated rapidly.

A Context of Worsening Risks

Unfortunately, numerous glaciers in the Amundsen Sea region including parts of the Thwaites system and the massive Pine Island Glacier also sit on retrograde slopes. These glaciers are seeing increasing fluxes of warm, deep water. By themselves they represent multiple feet of sea level rise (4-7 feet). Furthermore, Thwaites and Pine Island Glacier currently buttress a number of massive inland glaciers that become vulnerable to melt if inland-running retrograde slopes become flooded with warming ocean waters.

The very real concern is that Smith Glacier serves as a harbinger for near future events to come. As a result, coastal regions around the world are now under a heightened risk of swiftly rising seas and rapid coastal inundation over the coming years and decades.

Links:

Rapid Submarine Ice Melting in the Grounding Zones of Ice Shelves in West Antarctica

Grounding Line Retreat of Pope, Smith and Kholer Glaciers

Heinrich Event

Dr. Eric Rignot

Studies Offer Glimpse of Melting Under Antarctic Glaciers

Thwaites Glacier

Pine Island Glacier

Hat tip to Zack Labe

Hat tip to Miles h

“We Have Nowhere to Go” — Sea Level Rise is Devouring the Coast of West Africa

“I am very afraid for the future of this place. Sooner or later we will have to leave, but we have nowhere to go.” — Buabasah a resident of Fuvemeh, a West African town being swallowed by the sea as reported by Matteo Fagotto.

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A new, must read, report out in Foreign Policy by Matteo Fagotto highlights a widespread ongoing disruption due to sea level rise to the vulnerable coastal region of West Africa. And, for years now, scientists at the IPCC have been warning that just such an event could occur.

The coastal zone of West Africa stretches for 4,000 miles from Mauritania to the Congo. It includes highly populated regions surrounding low elevation cities and towns in such African nations as Gabon, Nigeria, Senegal, Guinea, The Ivory Coast, Sierra Leone, Cameroon, Liberia, and Ghana. Most industrial activity and food-growing is located near the coast of these nations — accounting for 56 percent of GDP for the region according to the World Bank. And coastal population concentrations in regions vulnerable to sea level rise are very high. In all about 31 percent of the 245 million people dwelling in West Africa live in this fragile land.

global-sea-level-rise

(Due to global warming and glacial melt spurred by fossil fuel burning, oceans are now rising at their fastest rates in 10,000 years. As a result, many coastal towns and cities around the world are under increasing threat of flooding. In West Africa, a recent report by Foreign Policy paints a picture of broadening inundation. Unfortunately, current rates of ocean rise are far slower than what human-caused climate change may set off over the coming decades. Image source: AVISO.)

Most of the coastline features a lagoonal geography that is very low-lying. Meanwhile, funds for coastal defenses like planting mangrove forests and pumping in sand to re-nourish beaches are difficult to procure. As a result, these large cities and population centers are highly vulnerable to impacts from human-forced climate change related to sea level rise.

The Great Flooding Begins

Ever since the early 1990s, scientific reports have highlighted the vulnerability of West Africa to inundation, flooding and loss of key industries, food growing and infrastructure due to glacial melt, thermal expansion of ocean waters set off by warming, and an increase in storm strength in the North Atlantic. All impacts that scientists feared would be coming due to a human-forced warming of the world. Now, just such an inundation and loss appears to be underway.

According to the recent report out in Foreign Policy, and according to other eyewitness accounts and news reports coming in from coastal West Africa during recent years, sea level rise and increasing erosion due to powerful storms continue to produce worsening impacts for the region. In one of the most glaring instances, the swelling surf is now in the process of destroying a Ghana fishing village (Fuvemeh) that recently housed 2,500 people. Homes, coconut plantations, and fishing wharfs have all been taken by the seas and swirling sands. But Fuvemeh is just one of thousands of like communities now confronting an onrush of waves that each year bites off as much as 80-120 feet of coastline.

(House destroyed by waves in Fuvemeh, Ghana. Sadly, sea level rise related impacts like this are now being seen all up and down West Africa’s 4,000 mile long coastline.)

Moreover, Foreigh Policy finds that megacities like Lagos (population 5.6 million) and large cities like Accra (population 1.6 million) are increasingly threatened by the encroaching waters. In Accra, the rainy season now causes an annual inundation of sections of the city — a new impact that resulted in 25 people losing their lives last year. Nouakchott, the capital of Mauritania and home to approximately 1 million people, now sees the loss of 80 feet of coastline along its Atlantic shore every year. Meanwhile, parts of Togo lost 118 feet of shore line last year alone. Along the coast from Gambia to Senegal and including communities like Cotonou and Lome, growing numbers of houses, hotels, restaurants, roads, and even water treatment plants are now little more than washed out husks and crumbling bits of infrastructure — lapped by a rising tide.

Heartbreak, Loss of Homes, Dislocation

As the waters rise, residents are forced to move inland. Younger, more mobile residents have often fled the region entirely. Others have rebuilt their homes further inland only to have them flooded again. Ocean productivity is on the decline in the region. Fish and other animals that supported coastal industries have migrated northward or succumbed to worsening ocean conditions. The combined losses have produced economic hardships as coastal cities see increasing gang activity, drug use, theft and violence.

Overall, the United Nations estimates that 5-10 percent of West Africa’s GDP will ultimately be lost due to impacts related to sea level rise. And the recent report by Foreign Policy points to growing evidence that the crisis is starting now. But the ever-more-human toll is nothing less than heart-wrenching.

West Africa Just One of Many Vulnerable Regions

Reports by Foreign Policy and others on the plight of coastal West Africa shines a light on sea level rise related hardships and losses throughout that region. However, numerous low-lying stretches of coastline are now facing similar problems. Bangladesh is currently seeing a wave of mass migration inland due to sea level rise related flooding. The Mi Cong Delta region is seeing its rice farms threatened by an influx of salt water. The Indus River Delta region in Pakistan is also experiencing mass migration away from coastlines. Coastal Pacific Islands are facing an existential threat due to sea level rise now. And the U.S. East Coast and Gulf Coasts are facing their own problems from worsening storm surge flooding and more widespread nuisance flooding due to sea level rise. So what we’re seeing in West Africa is part of a much larger overall global context.

Links:

West Africa is Being Swallowed by the Sea

West Africa Map

AVISO Sea Level Rise

IPCC: The Regional Impacts of Climate Change

Ghana’s Coastal Erosion — The Village Buried in Sand

Ghana Accra Floods

How The World’s Oceans Could be Running out of Fish

Drugs and Crime Mobilise International Support For West Africa Coast Initiative

Hat tip to Colorado Bob

Hat tip to Wili

Climate Change — Seas Are Now So High it Only Takes a King Tide to Flood the US East Coast

“It gets higher every year. I imagine it will be worse next year.” Guido Pena, Miami marina employee commenting on water levels during king tides.

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King tide. It’s a new term for an old phenomena. One that few people noticed before human-forced climate change began to push the world’s oceans higher and higher.

During spring and fall, the sun lines up with the moon and other astronomical bodies to produce a stronger gravitational pull on the Earth. This pull, in its turn, affects the tides — generating higher and lower tides over certain regions of the world.

(Rising ocean levels due to human-forced climate change is resulting in worsening instances of tidal flooding at times of high tide. In this video, a simple seasonal high tide is enough to flood major roads in Fort Lauderdale on October 17.)

King Tides — Turned into Flooding Events by Climate Change

During past years, these events were called astronomical high and low tides. They weren’t typically a news item because such tides often did not produce flooding. Past construction had placed buildings and key infrastructure above the typical annual range of even the astronomical high tides.

However, during the past century and, ever more-so during recent years, seas have been rising more and more rapidly due to human-caused climate change. A warming of the Earth due to fossil fuel burning that has melted glacial ice — flooding the oceans and causing its waters to thermally expand. As a result, parts of the U.S. East Coast now see ocean levels that are 1.5 feet or more higher than they were at the start of the 20th Century.

This rise, though modest compared to what will happen if global temperatures and greenhouse gas levels remain at currently elevated levels or continue to ramp higher, is now enough to turn astronomical high tides into a notable flooding event. An event that we have begun to call a king tide.

miami-sea-level-trend

(In places like Miami along the US East Coast, sea levels are rising at a swifter and swifter rate due to human-caused climate change. Note the acceleration in the rate of water rise since 2008 indicated in the above graph. Image source: FSU.)

A Climate Change Enabled Tidal Flooding Event Impacting Most of the U.S. East Coast

And over the past few days, from Florida to Boston, the US East Coast has been feeling the effects of just such a climate change caused sea level rise. In Florida, a debate between climate change denier republican Marco Rubio and his democratic opponent Patrick Murphy was held at a site where the local street was flooding due to salt water incursion. Murphy, responding to his opponent’s doubts that seas were actually rising stated:

“Look out your window, right? There’s two or three inches of saltwater on the roads right now. They were not built underwater. Go down to the Florida Keys. The reefs are dying from acidification and bleaching.”

All across Florida, residents were posting pictures on twitter of the rising ocean waters and commenting on the intensification of coastal flooding due to sea level rise during recent years. “It gets higher every year,” said Guido Peña, a Miami Marina employee where the water was shin deep Monday morning, in a statement to the Miami Herald. “I imagine it will be worse next year.”

All up and down the coastline, communities reeling after a raking blow from Hurricane Matthew were again seeing waters rushing up and past the dune line or invading low-lying streets and neighborhoods. But this flooding was due to no hurricane, just the added rise of waters caused by a fossil-fueled warming of the Earth, a melting of her glaciers, and the thermal expansion of her seas.

(King tide flooding enhanced by climate change is now able to completely submerge Long Wharf in Boston.)

In Boston, residents took pictures of a completely submerged Long Wharf yesterday. Mentions of climate change came along with the observations of flooding waters. These included some ominous notes for a future in which scientists are projecting at least another 2 feet of sea level rise for the US East Coast by mid-century (and possibly quite a bit more).

High Vulnerability for U.S. East Coast

Overall, the US East Coast is particularly vulnerable to climate change induced sea level rise. Much of the southeast is subsiding due to crustal rebound following the last ice age which compounds any overall ocean rise. In addition, changes in North Atlantic Ocean currents and wind patterns due to climate change will tend to cause water previously pulled north by the Gulf Stream to rebound against the coastline. An effect that could also add another 1-3 feet of water rise to any baseline total provided by glacial melt and thermal expansion.

Larger news sources like The Weather Channel have provided little context with regards to the impact of climate change on current king tides — simply stating that climate change may affect king tides in the future. However, we should be very clear that without climate change we would not see the flooding from these tides that is now apparent today.

Links:

When the Ocean Rolls onto the Roads, King Tide Sends a Message

What’s a King Tide and Why is it Flooding Boston’s Waterfront?

Marco Rubio Denies Climate Change as King Tides Flood Miami Streets

FSU

Hat tip to Jack Ridley

Hat tip to Greg

Hat tip to DT Lange

Hat tip to Jean Nagy

Hat tip to Ben Kennedy

Record-Hot 2016 Marks the Start of Bad Climate Consequences, Provides “Fierce Urgency” to Halt Worse Harms to Come

“…there is now strong evidence linking specific [extreme] events or an increase in their numbers to the human influence on climate.” — Coumou and Rahmstorf 2012.

“We are confronted with the fierce urgency of now. …We may cry out desperately for time to pause in her passage, but time is deaf to every plea and rushes on. Over the bleached bones and jumbled residues of numerous civilizations are written the pathetic words, ‘Too late.'” — Dr. Martin Luther King, Jr. [emphasis added]

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2016 is on track to be a record-hot year for the history books. Accumulations of heat-trapping gasses in the range of 402 ppm CO2 and 490 ppm CO2e have pushed the global temperature trend into an inexorable upward rise. Meanwhile, increasingly severe climate change-related events ranging from mass coral bleaching, to glacial and sea ice melt, to tree death, to ocean health decline, to the expanding ranges of tropical infectious diseases, to worsening extreme weather events have occurred the world over. This global temperature spike and related ramp-up of extreme events continued throughout a year that is setting up to follow 2014 and 2015 as the third record-hot year in a row.

(2015 saw a substantial jump in global temperatures. 2016 is also on track to hit new record highs. The above graph, by Gavin Schmidt of NASA GISS, provides a vivid illustration of an inexorable warming trend with 2016 as the hottest year yet. According to Gavin, a strong new record for 2016 appears to be a lock. Image source: Climate of Gavin.)

Now, after NASA’s report showing that September 2016 was 1.13 C hotter than 1880s averages (or 0.91 C hotter than NASA’s 20th-century baseline measure), this year is setting up to be the warmest ever recorded by a wide margin. Overall, the first nine months of 2016 have averaged 1.25 C above 1880s temperatures. Meanwhile, the climate year — which runs from December through November — is tracking 1.26 C above 1880s temperatures during the ten-month period of December to September.

2016 as much as 1.25 C Hotter than 1880s Averages

As a result, it appears likely that 2016 will see temperatures in the range of 1.19 C to 1.25 C hotter than 1880s averages. That’s about 0.1 C hotter than 2015 — which is pretty significant considering the fact that the average rate of decadal warming (the rounded rate of global warming every 10 years) has been in the range of 0.15 C since the late 1970s. This year’s temperatures now appear set to exceed 1998’s values by around 0.35 C — or about one-third of the entire warming total seen since large-scale human greenhouse gas emissions began during the late 19th century. This excession should permanently put to rest previous widely circulated false notions that global warming somehow stopped following the strong El Nino year of 1998.

Many responsible sources are now warning that current temperatures are uncomfortably close to two major climate thresholds — 1.5 C global warming and 2.0 C global warming. At the current rate of warming, we appear set to exceed the 1.5 C mark in the annual measure in just one to two decades. Hitting 2 C by or before mid-century has become a very real possibility. Scientists have been urging the global community to avoid 2 C warming before 2100 (and 1.5 C if at all possible), but the current path brings us to that level of warming in just over 30-50 years, not over the 84 years remaining in this century. And just maintaining current rates of warming without significant added feedbacks from the Earth System would result in Earth hitting close to 3 C warming by 2100 — a level that would inflict severe harm to life on Earth, including human civilizations.

september-of-2016

(According to NASA, September 2016 edged out September 2014 as the hottest September in the 136-year climate record. This occurred while the Equatorial Pacific was flipped into a cool phase, which tends to lower global temperatures. Despite this natural variability-related switch pulling global temperatures down, NASA shows a globe in which few regions experienced below-average temperatures and where the highest concentration of record-warm temperatures are centered near the northern polar region. This display of counter-trend warming and strong polar amplification are both signature effects of human-caused climate change. Image source: NASA GISS.)

Focusing back on 2016, it appears the La Nina that struggled throughout August and early September is again making a decent attempt to form, at least as a weak event. This should tend to pull October, November and December temperatures into the 1 to 1.1 C above 1880s departure range. As a result, final averages for 2016 should be slightly lower than averages for the period running from December to September. But, as noted above, we are still on track to see a very significant jump above the 2015 end atmospheric temperature totals.

Climate Impacts from Added Global Heat Continue to Worsen

All this extra heat in the system will work to worsen the already extreme climate and weather events we are seeing. Potentials for droughts, floods, heatwaves and wildfires will increase. High atmospheric moisture loading will continue to pump up peak storm potentials when storms do form. Added heat will tend to accumulate at the poles more than in the tropics or middle latitudes. As a result, upper-level wind patterns will likely continue to see more anomalous features along a worsening trend line. Ice in all forms will see stronger heat forcings overall, adding risk that both land and sea ice melt rates will increase.

impacts-to-the-cryosphere

(In the mid-2010s, Earth entered a temperature range averaging 1 C above pre-industrial levels. Such temperatures begin to threaten key climate impacts like permafrost thaw, 3-4 meters of sea-level rise from West Antarctic Ice Sheet melt, risk of up to 80 percent mountain glacier loss, complete Arctic sea ice loss during summer, and 6-7 meters of sea level rise from Greenland melt. In the near 1 C range, risks of these impacts, though a possibility, remain somewhat lower. But as temperatures approach 1.5 and 2 C above pre-industrial levels, risks rise even as West Antarctic glacial melt and polar ocean acidification start to become serious factors. Image source: Solving the Climate Stalemate.)

At 1 to 1.3 C above 1880s levels, we should see a quickening in the rate of sea-level rise. How much is uncertain. However, this temperature range is very close to peak Eemian Stage levels when oceans were around 15 to 25 feet higher than they are today. The current rapid rate of temperature change will also continue to have worsening impacts on creatures who are adapted to inhabit specific climate zones. The rapid rise in global temperatures is forcing an equally rapid movement of climate zones toward the poles and up mountains. This affects pretty much all life on Earth and unfortunately some species will be hard-pressed to handle the insult as certain habitats basically move off-planet. This impact is particularly true for corals, trees and other species that are unable to match the rapid pace of climate zone motion. We have already seen very severe impacts in the form of mass coral and tree death the world over. Warming in the 1 to 1.3 C range also provides an increasing ocean stratification pressure — one that has already been observed to increase the prevalence of ocean dead zones and one that will tend to shrink overall ocean vitality and productivity.

Fierce Urgency For Climate Action

Despite all these negative impacts, we are still currently outside the boundary of the worst potential results of climate change. Stresses are on the rise from various related factors, but these stresses have probably not yet reached a point of no return for human civilization and many of the reefs, forests, and living creatures we have grown to cherish. Rapid mitigation through a swift transition away from fossil fuels is still possible. Such a response now has a high likelihood of successfully protecting numerous civilizations while saving plant and animal species across the planet. That said, at this point, some damage is, sadly, unavoidable. But the simple fact that we are now starting to face the harmful consequences of a century and a half of fossil fuel burning is no excuse for inaction. To the contrary, the beginning of these harms should serve as a clarion call for our redoubled efforts.

Links:

NASA GISS

NOAA ESRL

NOAA El Nino

Climate of Gavin

The Truth About Climate Change

COP 21: Why 2 C?

Solving the Climate Stalemate

Hat tip to Kevin Jones

Hat tip to Florifulgurator

NASA Map Shows Large Portions of Greenland are Melting from Below

During recent years, as human fossil-fuel emissions have forced the Earth to warm, observations of Greenland’s surface has indicated a rising rate of melt. What has been less well-observed is melt rates beneath the ice and near the ice base. This is important because the pooling of water beneath the great ice sheet can help speed its movement toward ocean outlets, along with accumulating heat at the base of the ice — which can also quicken the pace of overall melt.

A new scientific study headed by NASA researchers has developed one of the first comprehensive maps of melt along Greenland’s basal zone, where the ice contacts the ground surface. What they have found is that large portions of Greenland are melting from below:

Greenland basal thaw map

(New, first-of-its-kind map shows extensive melt along the Greenland ice sheet base. Melt in this region is a sign that heat is building up beneath the ice as well as on top. Image source: NASA.)

This mapping study found that wide expanses of northern Greenland and pretty much all of southern Greenland are now experiencing melt at the ice sheet base. As the interior of Greenland has a cracked-bowl topography — with land bowing down into a central trough and numerous furrows connecting the ice sheet with the ocean — understanding where liquid water and heat are pooling at the bottom of the ice sheet will help scientists to get a better idea of how Greenland’s glaciers will respond to human-forced warming.

Joe MacGregor, lead study author and glaciologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland recently noted:

“We’re ultimately interested in understanding how the ice sheet flows and how it will behave in the future. If the ice at its bottom is at the melting-point temperature, or thawed, then there could be enough liquid water there for the ice to flow faster and affect how quickly it responds to climate change.”

Geothermal Melt, Ice Sheet Heat Accumulation, and Climate Change

Melt along the base of the Greenland ice sheet has long been influenced by heat welling up from or trapped near the Earth’s surface. The heavy, thick ice sheet densely packs the ground and rocks under it, which generates and amplifies geothermal hot-spots beneath Greenland. In addition, the ice creates a kind of insulating layer which locks that ground heat in. As a result, the bottom of the ice sheet is often tens of degrees warmer than its top.

Alone, this blanketing effect is enough to generate some melt along the bottom of Greenland. But now that the surface is melting more and more, heat transport from the ice surface to the bottom via liquid water funneling down to pool below is a more common occurrence.

Subglacial lake recharges due to surface melt Greenland

(Recharge of subglacial lake by surface melt near the Flade Isblink ice cap is an example of how surface melt can interact with basal melt, driving the formation of water at the ice sheet base. Image source: Nature.)

The way this heat transfer works is that rising temperatures over Greenland form more extensive surface lakes and melt ponds during the increasingly warm summers (and sometimes briefly during other periods). Often, the meltwater will find a crack in the ice and flow down to the ice interior. Sometimes the water remains suspended in the middle layers between the surface and the ice sheet base as a kind of heat bubble. At other times, the water will bore all the way down to the ground where it can form into pools or subglacial lakes.

At Flade Isblink in northeastern Greenland, such a filling of a subglacial lake was observed during the 2011 and 2012 melt years. As Greenland warms, such instances are likely to become more common. In this way, melt at the surface can add to the amount of heat trapped below the ice sheet — forming a kind of synergistic melt process.

The new NASA study helps our understanding of how such a process might unfold by showing the current extent of subsurface melt. The study combined physical models with observations to create this larger picture of bottom melt, telling a dramatic story of the opening period of human-forced Greenland melt, in which sub-surface melt is already very extensive.

Conditions in Context — The Level of Atmospheric Greenhouse Gasses is Now About Equal to Where They Were When the Greenland Ice Sheet First Formed

In context, the Greenland ice sheet is the largest repository of land ice remaining in the Northern Hemisphere. Covering a vast region of 1,710,000 square kilometers and rising up to 3 kilometers high at its tallest point, this ice sheet contains fully 2,850,000 cubic kilometers of ice. If all this ice melted, it would raise the world’s sea levels by around 7.2 meters (nearly 24 feet).

This enormous mountain of ice astride Greenland began to form about 11 to 18 million years ago during the Middle Miocene climate epoch. Back then, atmospheric carbon dioxide ranged from 405 to 500 parts per million. This decline from earlier, higher CO2 concentrations was allowing the world to cool enough to begin to support glacial ice in this region (around 4 C warmer than 1880s values).

Greenland_Mass_Balance

(Losses of Greenland mass from the surface zone have been accelerating during recent years. This loss has primarily been driven by human-forced warming of the Arctic. Though the North Atlantic Oscillation can generate melt variability by driving warm air flows toward or away from Greenland, the overall long-term driver has been a rapid warming of the Arctic region due to fossil-fuel emissions. Though we have a pretty good understanding of surface melt, our understanding of melt at the base of the ice sheet and heat accumulation there is less complete. Such an understanding may help us to predict future ice sheet behavior. Image source: Skeptical Science.)

Back then, Greenland’s ice was far smaller, far less extensive. It was a baby ice sheet that would grow into a behemoth as the Miocene cooled into the Pliocene — when CO2 levels fell to around 390 to 405 ppm — and then into the various ice ages and interglacials that followed (featuring atmospheric CO2 in the range of around 180 ppm during ice ages and around 275 ppm during interglacials).

Now, human fossil-fuel burning has put the ice sheet in a great global-warming time machine. With atmospheric CO2 levels hitting Middle Miocene ranges of 407.5 ppm at Mauna Loa this year, an accumulation of enough heat to significantly melt large portions of Greenland’s ice is a very real and growing concern. Exactly how that melt may unfold is still a big scientific mystery, but the risks are growing along with the heat and the new NASA basal melt study helps to shed a little light.

Links:

First Map of Thawed Areas Under Greenland Ice Sheet

NASA Maps Thawed Areas Under the Greenland Ice Sheet

Recharge of Subglacial Lake by Surface Melt Water in Northeast Greenland

Pliocene

Middle Miocene

Greenland Ice Sheet

Hat tip to Colorado Bob

Large Sections of Greenland Covered in Melt Ponds, Dark Snow

Over the past couple of days, temperatures across the Greenland Ice Sheet have really ramped up. The result has been a pretty significant mid-to-late season melt pulse. According to NSIDC, nearly 40 percent of the ice sheet surface has been affected by surface melt during recent days. And Greenland ice mass balance appears to have also taken a hit.

This surface melt pulse is, arguably, best portrayed in the satellite imagery:

Greenland Melt July 20

(Large section of Western Greenland near the Jackobshavn Glacier experiencing significant surface melt on July 20, 2016. Image source: LANCE MODIS.)

On July 20th, this approximate 300 x 70 mile swath of Western Greenland shows a number of distinct strong melt features. Near the interior edge of the melt zone we notice the light blue coloration indicative of widespread and general surface melt. From the satellite, this bluing gives the impression of a thin layer of surface water covering a widespread area of the ice sheet. But it is more likely that the blue tint comes from a plethora of small melt ponds and rivers that blend together in the lower resolution satellite shot to lend the impression of ubiquitous water coverage.

Large Melt Ponds, Dark Snow Over Western Greenland

Further in, we notice the darker blue swatches that indicate large melt ponds. Some of these ponds are quite extensive — measuring 1/4 to up to 1 mile in length. Ponds of this size tend to put a lot of pressure on the Greenland surface and can pretty quickly bore down into the ice sheet’s depths and interior. The water then either becomes locked in the ice — forming a kind of subglacial lake — or flows to base regions of the glacier where it can lubricate the ice — causing it to speed up.

Large Melt Ponds Dark Snow Western Greenland

(Close up satellite shot shows 1/4 to 1 mile long melt ponds, general melt ponding and a darkened Greenland Ice Sheet. Image source: LANCE MODIS.)

Still closer to the ice edge we find greatly darkened patches of ice. Darkening occurs when ice melt reveals and thickens past layers of ice sheet dust and soot accumulation. Each year, winds carry dust from land masses and soot from fires — which now, due to rapid Earth warming, burn more frequently over the Arctic and near-Arctic — to the ice sheet where it accumulates. This darker material is then covered by the annual layers of snowfall. If enough snow and ice melts, the yearly layers of dust and soot accumulation can concentrate into a gray-black covering. Such a covering is clearly visible in the July 20 satellite imagery above.

According to Dr. Jason Box, as much as 5.6 percent of the Greenland Ice Sheet was covered by this darkening, which he calls Dark Snow, as recently as 2014. Darkening of the Greenland ice sheet can accelerate melt as it reduces the ice sheet’s ability to reflect the sun’s rays — resulting in more overall heat absorption.

Substantial Northeastern Greenland Melt Also Visible

Zachariae Surface Melt Darkening

(Zacharie Isstrom Glacier in Northeastern Greenland shows significant melt in July 20 satellite shot. Image source: LANCE MODIS.)

Though surface melt and darkening is quite extensive along the southwestern flank of Greenland, toward the north and east, widespread surface melt, ponding and ice darkening is also visible over sections of the Zachariae Glacier. Here, in a far northern section of Greenland that borders the Arctic Ocean, we find an approximate 100 x 20 mile region of melting and darkening ice. Note the tell-tale bluing and dark gray patches visible in the above image.

For this region, ice has tended to experience more melt during recent years as sea ice within the Fram Strait and Greenland Sea has receded. This has revealed more darker ocean surfaces which, in turn, has absorbed more incoming solar radiation resulting in increased warming for this section of Greenland.

Conditions in Context — Human-Forced Warming Pushing Greenland to Melt Faster

Overall, Greenland melt is this year less extensive than the record 2012 melt season. However, the current mid-to-late season pulse has forced a big melt acceleration that may result in melt that exceeds 250 billion tons of ice loss for 2016 (or the average over recent years). In the pretty near future, continued high global temperatures and additional warming due to human fossil fuel emissions will almost certainly push Greenland to melt at a faster pace.

To this point, the Earth has now warmed by more than 1 C above Preindustrial temperatures. And a range of 1-2 C warming from this baseline in past climate eras such as the Eemian resulted in a 10-20 foot rise in world ocean levels. We’re in this temperature range now. So that’s pretty bad news for sea level rise — to which Greenland now contributes enough melt to lift seas by about 0.75 mm every year. The only real questions at this point are how fast will that already substantial melt accelerate, and will we halt fossil fuel burning swiftly enough to slow it down.

Links/Attribution/Statements

LANCE MODIS

The National Snow and Ice Data Center

Greenland Surface Mass Budget

These Stunning Photos of Greenland’s Dark Snow Should Worry You

The Dark Snow Project (please support)

Hat tip to Andy in San Diego

Hat tip to DT Lange

Scribbler-sponsored note on Trump:

Trump Chooses Climate Change Denier as Energy Advisor

Greenland’s Contribution to Sea Level Rise Doubled During 2011-2014 — Larger Melt Pulses on the Horizon

According to a new report, the Greenland Ice Sheet lost one trillion tons of water due to melt during the four-year period from 2011 through 2014. That’s about double the typical rate of loss during the 1990s through mid-2000s. Subsequently, Greenland’s contribution to sea-level rise also doubled. As a result, Greenland alone contributed 0.75 mm of sea-level rise every year during the 2011 to 2014 period.

(The above video briefly explains the findings of a new scientific study indicating a doubling in the rate of Greenland melt during 2011 through 2014.)

Bear in mind, the study focuses on Greenland only. Those numbers don’t include thermal expansion from the world’s warming oceans. Nor do they include an increasing amount of melt from Antarctica. Nor do they include large volumes of melt coming from the world’s rapidly disappearing mountain glaciers. Together, all of these in total are pushing sea levels higher by around 4 mm per year during the 2011 through 2016 period. That’s about 1 mm more per year than the 1993 to 2009 period. But the greater additional contribution appears to be coming from melting glaciers in Greenland and Antarctica.

The new Greenland Study found that melt averaged around 250 billion tons per year over the four-year period. This included a single melt year, 2012, in which Greenland contributed about half a trillion tons of melt water. The massive 2012 melt was spurred by high Greenland surface temperatures during summer which resulted in spiking surface melt rates during June, July, and August. At the time, a powerful high pressure system focused heat across the ice sheet which caused most of the surface area of Greenland’s glaciers to experience melt.

According to the study:

During 2011–2014, Greenland mass loss averaged 269 ± 51 Gt/yr. Atmospherically driven losses were widespread, with surface melt variability driving large fluctuations in the annual mass deficit. Terminus regions of five dynamically thinning glaciers, which constitute less than 1% of Greenland’s area, contributed more than 12% of the net ice loss. This high-resolution record demonstrates that mass deficits extending over small spatial and temporal scales have made a relatively large contribution to recent ice sheet imbalance.

In other words, melt at the margins of the ice sheet and large surface melt pulses during brief periods were the primary contributors to increasing melt rated during the study period.

Annual Mass Loss from Greenland and Antarctica

(Annual mass losses from Greenland and Antarctica are accelerating. This results in increasing rates of global sea level rise. While mass loss in Antarctica has recently primarily been driven by basal melt, surface melt has been the chief contributor to Greenland mass loss. In addition, the highly variable nature of surface mass loss along with its tendency to create brief, intense melt pulses is some cause for concern. Image source: Charting Ice Sheet Contributions to Global Sea Level Rise.)

The study found that surface melt rates were highly variable and dependent upon weather — with a strongly negative North Atlantic Oscillation contributing to conditions that enhanced melt during 2012. In this case, it appears that natural variability is beginning to be pushed by human-forced warming into a phase where certain years will preferentially further enhance Greenland melt. To this point, the tendency for large surface melt spikes was found to have increased during recent years. In contrast to Antarctica, where warming oceans contact glacial cliff faces and ice shelf undersides to accelerate melt, in Greenland, surface melt appears to currently be playing a bigger role in driving melt acceleration.

Surface melt can produce odd and unstable patterns of melt ponding and runoff over large ice sheets like Greenland. And as Greenland continues to warm due to human-forced climate change, an increasing risk of glacial outburst floods can be the result. The highly variable nature of surface melt is also a concern. In other words, overall warming can produce extreme, if brief, periods of warmth over Greenland that produce disproportionately large melt spikes. In this case, 2012 should not be seen as an outlier, but as the first of many future strong surface melt years — ones that will almost certainly surpass that year in melt intensity unless human-forced warming is somehow brought to a halt.

Links/Attribution/Statements

A High Resolution Record of Greenland Mass Balance

Excellent Comment on the Paper By Slate writer Phil Plait

Charting Ice Sheet Contributions to Global Sea Level Rise

Glacial Outburst Flood

Hat tip to Colorado Bob

Coastal Cities, Critical Infrastructure Unprepared to Face the Rising Tides of Climate Change

Civitasthe latin word for city and the root word for civilization. Civilization, in other words, is a collection of component cities. And, by extension, any major threat to a large number of cities is a threat to civilization itself. Such is the case with human-forced climate change.

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It’s a sad fact that many of the hundreds of coastal cities around the world are living on borrowed time. Current greenhouse gas levels — topping out near 408 parts per million CO2 (and 490 parts per million CO2e) this year — will need to fall in order to prevent 1-3 C of additional warming and 25 to 60 feet or more of sea level rise over the coming decades and centuries. And even if we somehow dialed atmospheric CO2 and CO2e levels back to 350 ppm, it’s likely that we’d still see seas eventually rise by 10-20 feet over the long term due to already destabilized glaciers in places like Greenland or West Antarctica.

But with fossil fuel burning continuing at near record levels globally, and with many corporations and political bodies around the world dragging feet on greenhouse gas emissions cuts, the level of heat-trapping carbon held aloft in our airs will continue to rise for some time. These vastly irresponsible actions will further heat the atmosphere and ocean — melting a greater share of the world’s land ice and forcing seas to ultimately rise even more. If CO2e exceeds a range of 550 to 650 parts per million — which could easily happen even under so-called moderate rates of fossil fuel burning before the middle of the 21st Century — then all the land ice on Earth will be placed under melt pressure. And that vast sum of ice melt represents about 220 feet of sea level rise long term so long as the greenhouse gas melt and heat pressure remains.

Sea level rise AVISO July 2016

(Seas have been rising in concert with ocean warming and fossil fuel burning since the start of the 20th Century. At first, during the first half of the 20th Century, rates of rise were less than 1 mm per year. By the 1993 through 2016 period, sea level rise averaged 3.39 mm per year. And since 2011, the rate of rise appears to have steepened into the range of 4 to 6 milimeters per year. Image source: AVISO.)

Even more disturbing is the fact that in the geological past, glacial melt has not tended to process in a gradual, orderly fashion. Instead, initial gradual melt has, in deep history, often been punctuated by very large melt pulses as glacial systems rapidly succumbed to warming environments. And with human warming now proceeding at a pace about 20 times faster than the end of the last ice age, the risk for rapid melt has been greatly enhanced.

Despite continued snide claims by climate change deniers to the contrary — it really is a global emergency. One that includes difficult impacts now and a rising risk of far worse impacts to come. A very real kind of long emergency for human civilization and the natural world combined. One made no less worse by its current deceptively slow, if massive and inexorable, advance.

Hundreds of Cities Under Threat

Due to this threat posed by human-forced warming of the global climate system, cities that have lasted for hundreds or thousands of years now face a serious risk that they will ultimately be devoured by rising tides. Around the world, nearly half of the world’s approximate 4,000 cities with populations of greater than 100,000 people sit on or near the coastline, at elevations below 220 feet, or near bodies of water that are vulnerable to sea level rise. Under the continued pressure of human-forced warming on global ocean levels, a good number (5-10 percent) of these cities may begin to succumb to rising tides in as little as a 10-30 years. And, long term, over 30-300 year time frames, pretty much all are threatened if the world continues burning fossil fuels.

Greenland Glacial Melt

(Glacial melt, like from this pond-riddled and melt-darkened section of Greenland as seen on July 8 of 2016, threatens many coastal cities this Century. With human warming of the Earth atmosphere approaching 2 C, the threat of large glacial outburst flood events that rapidly push sea levels higher is rising. But even gradual sea level rise is already disrupting cities and the infrastructure that supports them. Image source: LANCE MODIS.)

New Orleans, London, Sydney, Shanghai, Los Angeles, New York, Alexandria, Amsterdam, Miami, Norfolk, Washington DC, and Toyko are just a handful of the major cities that are mostly low-lying or that contain large low-lying sections. And all are below the 220 foot sea level rise line that current levels of fossil fuel burning will begin to put into long-term play before mid-Century.

Infrastructure is the First Vulnerability

While complete inundation by rising tides is the ultimate issue, cities do not have to face such drowning to fall under threat. Water supplies, transportation nodes and arteries, food supplies, and energy production and distribution facilities all represent lynch-pins that, if disrupted, can take down a city’s ability to effectively function. And sea level rise often threatens many or all of these critical supports well before the problem of total inundation becomes an issue.

Miami, for example, now faces a combination of these threats due to the presently emerging early outlier effects of human-forced sea level rise. There, just one foot of rising tides since the early 1870s has now put 2.4 million of Miami’s residents and 1.3 million homes within 4 feet of the high tide mark. By 2015, that relatively minor sea level rise had increased tidal flooding by 50 percent. Roadways and neighborhoods were more frequently cut off by the rising waters — which prompted the election of Philip Levine as Mayor of Miami Beach and the implementation of his 400 million dollar project to elevate roads and add pumps.

The city’s water supply, provided by a fresh water aquifer running through porous limestone, is protected from ocean salt water intrusion by a fresh water barrier of canals. A mere six additional inches of sea level rise will render the current system both ineffective and vulnerable to over-topping due to heavy rainfall events.

Power Stations, Roads, and Airports

By 2030, Miami is expected to see between 6-10 more inches of sea level rise. By the end of this Century, it will probably see at least 6 feet — and that’s if we don’t pursue business as usual fossil fuel burning and if the world’s glaciers mostly behave themselves by not giving us a big, angry melt pulse in response to our insults. The result is that not only Miami, but the far-flung critical infrastructure that supports it is also under threat.

In this context, Miami’s airport is just 8 feet above the high tide line. The nearby Turkey Point Nuclear facility which provides energy to the city and a big chunk of South Florida is about 6 feet above the high tide line. And though its reactors are elevated by another 20 feet of concrete buttressing, this Century’s predicted sea level rise would flood its grounds and surrounding roadways — likely rendering it inoperable.

Nuclear Stations Sea Level Rise

(Long term inland extent of sea level rise under 2 C and 4 C warming scenarios for US East and Gulf Coasts puts 13 nuclear facilities in the firing line. And an unexpected melt pulse or powerful storms riding on the top of sea level rise present a risk of flooded reactors. Such an inland rush of waters would also drown scores of coastal US cities, cut off roadways, flood aquifers, inundate crops, submerge airports, and sink conventional power stations. Image source: Nuclear Regulatory Commission, National Geographic, Climate Central.)

In the US, nine nuclear power stations are located on the coast. Another 13 are vulnerable to sea level rise. These sites are located near the ocean or along ocean fed rivers. They are ultimately vulnerable to sea level rise spurred by 2 or 4 degrees Celsius worth of warming. Without a herculean effort to not only reduce greenhouse gasses, but to recapture them from the atmosphere, 2 C warming is already locked in (this Century or longer term). The 4 C number is possible by late this Century under business as usual fossil fuel burning and is possible long term (500 year time scales) under the continuous 490 ppm CO2e forcing now in place.

Many large coal and gas power plants which also require heavy flows of water to support their operations are located near the coast. Oil refineries, which rely on shipping are often very close to sea level. Many major roadways are vulnerable to cut-off from sea level rise. And an amazingly large number of key airports are below a 20 foot elevation.  A small sampling includes San Diego International Airport at 13ft in elevation, Santa Barbara — 10 feet, Vancouver –14 feet, Portland 20 feet, JFK — 13 feet, La Guardia — runway elevations between 7 and 21 feet, Reagan National — 13 feet.

New York Also Armoring Against Rising Tides

In the northeastern US, another city has recently had a harsh global warming wake-up call. About a foot of east coast sea level rise added to the approximate 13 foot storm surge of Hurricane Sandy to flood Staten Island and large sections of lower Manhattan. The local power station flooded — propelling the city into darkness even as the subway system drowned and one neighborhood filled with water and burned at the same time.

Post Sandy responses have resulted in a flurry of activity. Fully 60 billion dollars has been spent to rebuild and a good chunk of that has gone to making the city more protected against both storms and rising sea levels. High rises are now required to lift critical infrastructure such as water pumps and spare generators into the upper stories should lower levels flood. A big flood resiliency effort, starting with the 3 billion dollar construction of a 10 foot high, two mile long flood barrier in 2017, is underway. One that may buttress much of lower Manhattan behind a U shaped wall meant to deflect both rising tides and worsening storms.  And a new park now features hills up to 70 feet above sea level.

Post-Glacial_Sea_Level

(At the end of the last ice age, as global temperatures approached 2 degrees Celsius above previous averages, large melt pulses from Antarctica and Northern Hemisphere Ice Sheets forced seas to rise by as much as 10 feet per Century. Human-forced warming is currently about 20 times faster than warming at the end of the last ice age. Current rates of warming and greenhouse gas emissions threaten to generate a 2 C warming by or even before the middle of this Century. Large melt pulses forced by such conditions would put cities like New York under risk of rapid inundation. Image source: Post-Glacial Sea Level Rise.)

These efforts appear to be aimed at facing off against another 1 foot of sea level rise for Manhattan by 2030 and a North Atlantic Ocean that is increasingly riled by powerful storms due to warming related climate instabilities. New York is digging in for the fight of its life. And for good reason. 10 percent of US gross domestic product funnels through this city of 8.5 million and over 100 billion dollars worth of real estate now sits in a high risk flood zone.

But build and buttress as it might, New York is hopeless in the long term if we can’t somehow stop human carbon emissions soon. If we can’t somehow start to draw carbon out of the air. If we can’t do these things, then New York, Miami and thousands of other coastal cities will ultimately face 25 feet of sea level rise or much, much worse. And the far flung infrastructures that they rely on will all, increasingly, need more and more costly and involved protections before they too succumb to the rising tides.

Links/Attribution/Statements:

Rising Seas Threat to Miami

Miami Nuisance Flooding Up by 50 Percent

As Waters Rise, Miami Beach Builds Higher Streets

Miami Herald — Sea Level Rise

Nuclear Regulatory Commission

Sea Level Rise — Are Coastal Nuke Plants Ready?

Sea Level Rise Risk to Coastal Nuclear Plants

Can New York Be Saved in the Era of Global Warming?

Post-Glacial Sea Level Rise

New Park Built to Withstand Epic Storms

Global Cities Map

Ancient Civilization

Scientific hat tip to Dr. James Hansen

Scientific hat tip to Dr. Eric Rignot

Scientific hat tip to Dr. Jason Box

Hat tip to DT Lange

Hat tip to Scott

Hat tip to Genomik

Hat tip to Cate

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