Constant Arctic Heatwave Sends World’s Largest Ice Cap Hurtling Seaward

Svalbard. Until lately, a little-known locale situated between the previously frigid extreme North Atlantic and the Arctic Ocean about 500 miles east of Greenland. Typically a frozen island Archipelago, this pristine and sparsely inhabited redoubt has, over the past few years been ground zero for the assaults of an ongoing and extreme polar heat amplification.

During winters, temperatures in Svalbard are generally, well, Arctic. But in recent years abnormal winter warmth featuring temperatures ten, twenty, even thirty degrees above 20th century averages have been experienced with increasing frequency. This year, during one of the warmest winters on record for the Arctic, local Svalbard temperatures rocketed to as much as 40 degrees F above the usual range and for extended periods remained in the range of +20 to +30 F positive anomaly.

For all of February of 2014, the average temperature for this Arctic island chain was -1 C (about 30 F), a full 15 degrees C above average and a period that featured many readings at or above freezing. It was an unprecedented event for an island that features one of the largest ice caps on Earth.

Austfonna, Svalbard’s Ice Giant, Takes a Fall

Austfonna sprawls across the northeast section of Nordaustlandet, one of Svalbard’s many islands. The ice cap covers fully 8,000 square miles and features an ice dome pinnacle looming 750 meters high making it the largest of its ilk. Though not as grand as the great ice sheets of Greenland or West Antarctica, Austfonna still contains an immense amount of water. Less stable than ice sheets, deteriorating ice caps currently contribute to almost 50% of global sea level rise.

Austfonna Sentinel 1 Pace of Outlet

(ESA’s Sentinel provides false-color imagery of the Austfonna Ice Cap sliding into the Barents Sea. Right panel imagery provides observed changes in outlet speed from 1995, 2008, and 2014. Flow rates are indicated by color contour as slow [dark blue] to fast [red]. Image source: ESA via BBC.)

But Austfonna, the largest of these, was thought to be somewhat insulated from the insults plaguing most of the world’s ice caps. Its far northern and previously frigid location at Svalbard made it less vulnerable. But that was before sea ice loss opened the gates to an ongoing and ever-increasing assault of warm winds.

Now, according to findings made by the European Space Agency’s (ESA) Sentinel 1 Spacecraft, it appears that the ongoing assault of heat has at last destabilized the great Austfonna. For according to radar altimetry readings, the pace of the ice cap’s motion toward the Barents Sea has, over the past three years, accelerated to an extraordinary speed ten times more rapid than its previous pace (Sentinel’s findings are due to be published soon in a prominent scientific journal).

Lead study author Prof Andy Sheperd of Leeds University notes:

“We’ve observed Austfonna with various satellite radar datasets over the past 20 years, and it hasn’t done very much. But we’ve now looked at it again with the new Sentienl-1a spacecraft, and it’s clear it has speeded up quite considerably in the last two or three years. It is now flowing at least 10 times faster than previously measured.”

Austfonna is just the most recent of many very large ice caps, ice sheets, or glaciers now showing increasing rates of motion toward the world ocean. In many cases, once destabilized, these great bodies of frozen water have reached a point of no return as they lunge toward an inevitable destiny of melt, outflow, and disintegration. The most recent and ongoing rash of destabilizations are likely to have significant implications for global sea level rise due to human caused warming going forward. And with human heat forcing and amplifying Earth System feedbacks still on the rise, the glacial butcher tally isn’t likely to end any time soon.

Links

Sentinel Spies Ice Cap Speed-Up

Arctic Heat in Winter: February 2 Temperature Anomaly Hits + 13 F For Entire Arctic

ESA

Warm February Provides Extreme Record on Svalbard

Hat tip to Colorado Bob

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What Does a World at 400 Parts Per Million CO2 Look Like Long-Term?

In the give and take of the current global warming debate, it’s easy to lose track of context. Thankfully, we have a geological history to use as a window to our past. And by using that window we can see what the world will look like if CO2 levels stay where they are for long periods of time. In this first exploration, we’ll look at current CO2 levels — around 400 parts per million to give a decent idea of how the world will change if we don’t undertake the challenge of reducing these high levels of greenhouse gasses.

When Was the Last Time CO2 Levels Were This High?

It is important to note that relatively small changes in CO2 can lead to ample warming. During the last ice age, more than 10,000 years ago, CO2 levels were stable in a range between 180 and 210 parts per million. At the ice age’s cessation, CO2 levels rose to 280 parts per million. This relatively small rise of about 70 parts per million had dramatic consequences. Temperatures rose by about 5.5 degrees Celcius (10 degrees Fahrenheit).

Today, industrial activity and fossil fuel consumption has resulted in nearly 120 parts per million of additional CO2 added to the atmosphere. This addition has occurred over a very short time-scale when compared to past changes in CO2 levels and additions of 2-3 parts per million continue each year.

However, assuming CO2 were to stabilize. Assuming that, somehow, the world is able to reign in emissions enough to keep CO2 levels steady at 400 parts per million, what would happen?

As mentioned above, geological history gives us a basic notion. Long ago, about 3 million years ago, CO2 levels were steady in a range of 365-410 parts per million. This geological era was called the Pliocene.

What Did the Pliocene Look Like?

What would seem like a rather small difference in CO2 levels had dramatic effects. The first was that sea levels were 75 feet higher than they are currently today. The second was that average temperatures around the world were 3-4 degrees Celsius warmer (5.4-7.2 degrees Fahrenheit). Greenland and the West Antarctic Ice Sheet were ice free at CO2 levels of 400 parts per million and temperatures 3 degrees Celsius warmer than today. Arctic temperatures were much warmer — 8-16 degrees Celsius warmer than today.

This is the kind of world we can expect if CO2 levels are sustained at 400 parts per million.

Why Do Climate Models Under-predict Sea Level and Temperature Rise?

These historic temperature increases are much greater than those predicted by current climate models. The reason is that these models have not been able to take into account all the feedbacks to CO2 forcing that are intrinsic to the climate system. Models, by their nature, are simplifications and are only as good as the data that goes into them. But looking at geological history, it is quite clear that current climate models underestimate temperature and sea level rise given current levels of CO2.

How Fast Will Climate Change at a Constant 400 Parts Per Million CO2?

If, somehow, the world were able to stabilize CO2 at 400 parts per million, how fast would the world see 75 foot sea levels and 3-4 degree Celsius temperature increases? In short, this is the one million dollar question. Fossil fuel special interests would like us to believe that these changes would be gradual and slow to happen. In fact, many fossil fuel interests would have us believe that climate change isn’t happening at all, or, if it is, that its impacts will be far milder than the geological record would indicate. Sadly, the fossil fuel companies are misguiding themselves and the rest of us for their own short-term economic gain.

Paleoclimate data points to rapid, non-linear, responses to increases in CO2 levels. In some cases, temperatures have rebalanced over the course of decades and normally during periods of centuries or less. In some of the most radical cases, the changes have occurred on time scales measuring as few as ten years. Given the rapid rise of CO2 to its current state and likely feedbacks to result, we could expect to see a majority of that 75 feet in 300-600 years. That means severe consequences could ramp up before the end of this century pushing sea levels by ten to fifteen feet or more. You won’t see the IPCC posting a report that makes this kind of a statement, but it certainly is a potential, even if CO2 levels stabilize at ‘only’ 400 parts per million.

Most likely, current predictions of 1-2 meters of sea level rise by the end of this century is still a conservative forecast even for what would happen in a world where CO2 levels remain stable at 400 ppm. Even at constant CO2 levels of 400 ppm, we are looking at sea level rises in the range of 1.5-4.6 meters per century or more.

Business As Usual Estimates Place CO2 at Around 1000 Parts Per Million By the End of This Century; What Would That World Look Like?

Unfortunately, the world has yet to adopt serious policies that curtail greenhouse gas emission or reduce the level of CO2 in the atmosphere. And, even more concerning, world carbon sinks are beginning to contribute their own greenhouse gasses to the world climate system. Unless very rapid emissions reduction regimes are put into place, the world of the Pliocene, as strange and radically different as it may seem, will look like paradise compared to a world that reaches 600, 800, 0r 1000 parts per million CO2. And it is this increasing likelihood that we will explore in another blog.

Please help support our continuing efforts.

Please help support our continuing efforts.

Links:

http://www.nasa.gov/topics/earth/features/rapid-change-feature.html

http://www.skepticalscience.com/what-was-it-like-the-last-time-co2-levels-were-this-high.html

NSIDC: Greenland Experiencing “Extraordinarily High Melting.”

Image

Back in July, Greenland experienced a very rare period of warm weather that resulted in melting over all of Greenland’s ice cap. That said, for this summer, this single period of extremely warm weather was just the capstone of what has been an extraordinary melt season.

The National Snow and Ice Data Center (NSIDC) recently released a report including statements on Greenland’s record high elevation melt, noting that such events tend to occur with 150 year frequency (according to ice cores, the last such event happened in 1889). But the NSIDC was quick to note that lower elevation melting was perhaps even more extraordinary:

“Perhaps more important, however, is the extraordinary high melting occurring this year around the lower elevations in Greenland. Figure 6 (above) shows that the first few months of melt exceeded past higher-than-average melt seasons.”

Taking a look at the figure, it is pretty clear that Greenland melt through late July has far exceeded even the record 2010 and 2011 melt seasons. NSIDC went on to report that this year’s melt resulted in flooding for a number of rivers in Greenland and this, in turn, resulted in instances of structural damage.

Putting this event in context, it is important to note that increased volumes of melt from Greenland also increase the rate of sea level rise. Furthermore, increased rates of melt in Greenland result in large iceberg calving events that directly impact world shipping and maritime industries. One such calving event in July resulted in an iceberg larger than Manhattan breaking off from the ice sheet.

Finally, the unprecedented melt in Greenland did not occur in a vacuum. This summer has also brought record sea ice melt as well as a record early snow melt to the Northern Hemisphere. This series of events punctuates an ongoing trend that is years ahead of climate scientist’s expectations for impacts to global warming. In short, these kinds of events were predicted, but for one, two, or three decades on — not now. In particular, the discrepancy for sea ice melt and model predictions has been among the most glaring of these earlier than expected melt events. This issue is one we will explore more deeply in another post.

For now, I’ll leave you with this record of albedo loss for Greenland so far this year:

Image

(NOTE: Albedo measures an ice sheet’s reflectivity. The less reflective an ice sheet becomes, the more heat it absorbs and the faster it tends to melt.)

Please help support our continuing efforts.

Please help support our continuing efforts.

Links:

http://nsidc.org/arcticseaicenews/

http://www.greenlandmelting.com/

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