Tumbling Down the Rabbit Hole Toward a Second Great Dying? World Ocean Shows Signs of Coming Extinction.

The last time Earth experienced a Great Dying was during a dangerous transition from glaciation and to hothouse. We’re doing the same thing by burning fossil fuels today. And if we are sensitive to the lessons of our geological past, we’ll put a stop to it soon. Or else doesn’t even begin to characterize this necessary, moral choice.

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The Great Dying of 252 million years ago began, as it does today, with a great burning and release of ancient carbon. The Siberian flood basalts erupted. Spilling lava over ancient coal beds, they dumped carbon into the air at a rate of around 1-2 billion tons per year. Greenhouse gasses built in the atmosphere and the world warmed. Glacier melt and episodes of increasingly violent rainfall over the single land mass — Pangaea — generated an ocean in which large volumes of fresh water pooled at the top. Because fresh water is less dense than salt water, it floats at the surface — creating a layer that is resistant to mixing with water at other levels.

Algae Blooms and Red Tides in the Stratified Ocean

This stratified ocean state began to cut the life-giving thread of the world’s great waters. Reduced mixing meant the great ocean currents slowed. Oxygen transport into the depths declined. Moreover, a constant rain of debris in the form of particulate matter from burning forests and nitrogen oxides from the smoldering coal beds fertilized the ocean surface. Food for algae also came from increasing continental run-off. And a spike in iron loading due to glacial melt added yet more fertilizer. Great microbial blooms covered the world ocean, painting its face neon green, blue, or blood red.

antarctic-algae-bloom-terra

(Stratified Ocean waters hosting massive algae blooms. It’s a combination that can quickly rob ocean waters of oxygen. During the Permian, a transition to stratified and then Canfield Ocean conditions led to the worst mass extinction event in the history of life on Earth. Today, the Southern Ocean’s waters are increasingly stratified due to glacial melt run-off of fresh water. In addition, these waters also host very large algae blooms like the ones seen above in a NASA satellite shot from 2012. Image source: NASA and Live Science.)

Rising CO2 levels increased ocean acidification even as the blooms spread toxins through the waters. When the blooms finally exhausted all the available food in their given region, they died off en masse. And by decay they further robbed the waters of life-giving oxygen. At this point the strains to ocean life became extreme and the first mass deaths began to occur. The stress opened pathways for disease. And the warming, de-oxygenating waters forced migrations to different Latitudinal zones and ocean depths. What life there was that couldn’t move, or couldn’t move fast enough died in place.

Transitioning to a Canfield Ocean

At first, ocean deaths appeared prominently in the bottom regions that saw the most rapid declines in oxygen levels and the swiftest increases in temperatures. For not only did the fresh water at the surface of the world’s oceans prevent mixing — it also prevented the oceans from ventilating heat into the air. Instead, the ocean heat was increasingly trapped at depth. Aiding this process of heat transport into the world’s deeps was a bottom water formation that issued from the hot Equator. There, evaporation at the surface increased saltiness. The heavier, hotter, saltier waters sank — carrying with them the Equatorial surface heat which they then delivered to the ocean bottom.

The hot, low oxygen bottom water became increasingly loaded with methane as the heat activated frozen stores. It created an environment where a nasty little set of primordial, hydrogen sulfide producing, creatures could thrive.  These little microbes cannot live in oxygen rich environments. But warm, anoxic bottom waters are more like the ancient environments from which they emerged. Times long past when the world was ruled by microbes in conditions that were simply deadly to the more complex and cold-loving life forms of later times. To most life, the hydrogen sulfide gas produced by these little monsters is a deadly toxin.

Ancient ocean conditions

(Oxygen, iron and hydrogen sulfide content of the world’s oceans over the past 4 billion years. Ancient oceans were hotter than today. They were rich in iron and densely populated with hydrogen sulfide producing bacteria. They were also anoxic. During hothouse events, oceans can again lapse into these ancient ocean states. Called Canfield Ocean environments and named after Dr. Donald Canfield who discovered them, these states are extremely deadly to ocean life. If they become too deeply entrenched, Canfield Oceans can also transform the global atmosphere, resulting in extinctions of land animals as well. Such an event was thought to be the primary killing mechanism during the Permian Extinction. Image source: Nature.)

The rotten-eggs stinking, hydrogen sulfide filled waters at first did their dirty work in silence at the bottom of the warming world ocean. But, steadily, anoxia progressed upward, providing pathways for the hydrogen sulfide producing bacteria to fill up the oceans. Death expanded from the bottom toward the surface.

In all the great mass extinction events but, possibly, one, this heat-driven filling up of the world ocean with deadly hydrogen sulfide gas during hothouse periods represents the major killing mechanism. The other impacts of hothouse waters — ocean acidification and habitat displacement — do provide killing stresses. But the combined zero oxygen environment filled with a deadly gas generates zones of near absolute death in which few things but microbes and jellyfish can live. In rock strata, the anoxic, zones are marked by regions of black as the hydrogen sulfide producing bacteria-filled waters eventually take on the color of tar. In the lesser extinctions, these black zones are confined to the lower ocean levels. In the greater ones, they rise higher and higher.

During the Great Dying, the oceans brimmed full of the stuff. Black, purple and neon green waters bubbled to the surface to belch their lethal loads of hydrogen sulfide gas into the airs. The gas was deadly toxic to land plants and animals alike. And it eventually wafted into the skies, turning it from blue to green and eating away at the protective ozone layer.

In this terrible way, more than 99 percent of all living things were killed off. Of species, about 95 percent of ocean forms were lost with around 80 percent of the land forms being wiped out.

Early Signs of a New Ocean Extinction

The Great Dying of the Permian Extinction 200 million years ago should be a warning to anyone still enamored with the notion that today’s terrifying fossil fuel burning results in any future that is not horrible, wretched, bleak. Today, we dump 11 billion tons of carbon into the air each year — at least six times faster than during the Great Dying. Today, the great melting glaciers are beginning the painful process of ocean death by spreading out their films of stratifying, iron-loaded fresh water. Today fossil fuel industry, industrial farming and warming all together are fertilizing the ocean surface with nitrous oxides, particulates, phosphates flushed down rivers, and an overall increased runoff due to a multiplication of extreme rainfall events.

(The hot blob in the Pacific Ocean is setting off the largest red tide on record. Just one of many dangerous impacts to sea life due to this large region of abnormally warm water.)

And the impacts are visible to anyone who cares to look. In the Pacific Ocean, a climate change related blob of hot water is resulting in mass ocean creature die offs. Low oxygen waters beneath the blob are wrecking large zones of ocean productivity and risking the proliferation of deadly hydrogen sulfide producing bacteria. The largest red tide on record has spun off the hot blob. Covering waters 40 miles wide and 600 feet deep, it has left piles and piles of dead shellfish rotting on beaches across the North American West Coast.

Across the Continent, the Chesapeake Bay suffers a proliferation of dead zones and greatly reduced productivity. There’s a rising risk that, during coming years, increased warming will deliver a heavy blow to life in the Bay and turn one of the world’s greatest estuaries into a large hydrogen sulfide production zone similar to the Baltic Sea. In the Gulf of Mexico, a similar dead zone emerges near the outlet of the Mississippi. And out in the Atlantic Ocean, mobile dead zones now swirl providing a roving surface hazard to both the deep open waters and to the coastal regions that now sit in the firing line.

In the Arctic, recently ice-freed waters are now the host of massive blue and green Algae blooms.

Barent Algae Bloom July 2015

(Large blue and green algae bloom covering the southern Barents Sea during late July of 2015. Large algae blooms are now a frequent feature of previously ice covered waters in a warming Arctic. Image source: LANCE-MODIS.)

Ever since the mid 2000s a massive algae bloom like the one pictured above has dominated the Barents Sea during summer time. Often running as deep as 400 feet, this sprawling mat can rapidly deplete northern waters of vitalizing oxygen and result in mass fish kills. Waters around Greenland, in the East Siberian Sea, the Chukchi, and the Beaufort have also hosted large, and potentially ocean-health threatening algae blooms.

And, in the polynyas and open waters off a melting Antarctica, massive algae blooms are also starting to form. Some of the blooms are so dense they emit a nasty rotten-eggs smell — a sign that sulfide producing bacteria may already be active in some of these waters. Fed by iron from melting glaciers, these immense blooms represent rapid explosions of life that can equally rapidly deplete waters of nutrients and then oxygen as they die off.

The blooms and the related expanding, low oxygen dead zones now range the entire world ocean. And where we see the red, the neon green, the cloudy light blue what we see are the signs of another ocean extinction in the making. An extinction that is likely building faster than at any time in the geological past. But we may still be able to avoid another great dying. The amount of carbon we’ve emitted into the world’s airs is immense, but it is still but a fraction of the carbon explosion that resulted in the Permian die-off. It is still a tiny fraction of the carbon that remains in the ground. The carbon that could be burned but shouldn’t. And a rapid cessation of fossil fuel burning now should, hopefully, be enough to prevent another hothouse spurred great dying in the oceans and upon the lands.

As for continued burning of fossil fuels — that results in ever greater risk of unleashing the horrors of the ancient hothouse. A set of now stirring monsters that we should carefully allow to fall back into slumber — leaving them to rest in dreams of the great long ago where they belong.

Links:

A Deadly Climb From Glaciation to Hothouse: Why the Permian-Triassic Extinction is Relevant to Current Warming

Antarctic Glaciers are Loading the Southern Ocean Up With Iron (Not the Good News Some Are Making it Out to Be)

Large Algae Blooms off Antarctica

Under A Green Sky

Awakening the Horrors of the Ancient Hothouse

Canfield Oceans

Nature

K-T Extinction — Impact or Hothouse Caused?

Climate Change Happening Faster Than Scientists Predicted

How Global Warming Sets off Extreme Weather

Hot Pacific Ocean Runs Bloody

Pacific Algae Bloom is The Biggest Red Tide We’ve Ever Seen

Chesapeake Bay Dead Zones

The Atlantic Ocean’s Whirlpool Dead Zones

LANCE-MODIS

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Through The Looking Glass of The Great Dying: New Study Finds Ocean Stratification Proceeded Rapidly Over Past 150 Years

During the terrible mass extinction event at the Permian-Triassic boundary about 250 million years ago nearly all life on Earth was snuffed out. The event, which geologists have dubbed “The Great Dying,” occurred during a period of rapid warming on the tail end of a long period of glaciation (see A Deadly Climb From Glaciation to Hothouse: Why the Permian-Triassic Extinction is Pertinent to Human Warming). According to reports by Dr. Peter Ward, a prominent geologist specializing in causes of previous mass extinctions, the Permian extinction was composed of three smaller extinction events occurring over the course of about 50,000 to 80,000 years which together wiped out 96% of all marine species and 70% of all land species. Ward’s book “Under a Green Sky,” in my view, together with Hansen’s seminal “Storms of My Grandchildren” provide an excellent if terrible rough allegory of the climate beast we seem to be in the process of awakening.

A2 model run

(NCAR A2 model run shows global surface temperatures near those last seen during the PETM and Permian/Triassic extinction events by 2090 under a middle-range fossil fuel emissions scenario. A2 does include some added emissions via amplifying feedbacks from massive polar methane or CO2 stores along with other Earth Systems feedbacks. It is worth nothing that the P/T extinction occurred at the end of a glacial period while the PETM did not and was notably less pronounced. It also worth noting that global average temperatures are currently about .2 C above those seen in the 1990s.)

As noted above, Ward’s work focused on causes and what he found at numerous dig sites around the world was evidence of a ‘Great Dying’ that began at the ocean floor, proceeded upward from the depths, and eventually came to transcend the ocean boundary and inflict a similar, if less pronounced, lethality upon terrestrial organisms. The mechanism Ward proposed for the worst extinction in Earth’s geological memory involved how oceans and, in particular, living creatures in the oceans, respond to rapid warming. Ward found that during periods of high heat called hothouse states, oceans first became anoxic and stratified and then, during the worst events, transitioned to a deadly primordial state called a Canfield Ocean.

A stratified ocean is one in which the layers become inverted and do not mix. Warm water is avected toward the ocean bottom and a cooler layer on top keeps that warm layer in place. The warmer water beneath is oxygen poor and this results in more anaerobic microbes living in the deep ocean. Overall, global ocean warming also contributes to an anoxic state. Many of these microbes produce toxins that are deadly to oxygen dependent organisms. As they multiplied, the combined low oxygen/high toxicity environment created a layer of death that slowly rose up through the world ocean system.

The primary lethal agent Ward proposed for this action was hydrogen sulfide gas. This deadly gas, which has an effect similar to that of cyanide gas, is produced in prodigious quantities by an anaerobic bacteria whose remnants lurk in the world’s deep oceans. In lower quantities they turn the water pink or purple, in greater quantities — black. Oxygen is toxic to these primordial bacteria. And so, in the mixed oceans of the Holocene all the way back to the PETM boundary layer, these little monsters were kept in check by a relatively high oxygen content. But start to shut down ocean mixing, start to make the oceans more stratified and less oxygen rich and you begin to let these dragons of our past out of their ancient cages. And once they get on the move, these creatures of Earth’s deep history can do extreme and severe harm.

Ward hypothesized that these ancient organisms and the gas they produced eventually came to fill the oceans and then spill out into the atmosphere.

An anoxic, stratified ocean full of anaerobic organisms and out-gassing hydrogen sulfide to the atmosphere is a primordial sea state known as a Canfield Ocean. And Ward found that such hot, toxic waters were the lethal agent that most likely snuffed out nearly all life 250 million years ago.

A Climate Hockey Stick for the World Ocean System: Oceans Show Marked and Rapid Stratification Over the Past 150 Years

Peter Ward’s tone was nothing if not fearful in his book ‘Under a Green Sky.’ He wrote with the wisdom of a man who has come face to face with terrible limits time and time again. He wrote with the wisdom of a man shocked by some of the hardest truths of our world. He also made a plea — could scientists and experts of different fields please work together to give humanity a better measure of the risks he saw to be plainly visible.

Chief among these risks, according to Ward, included a rapidly warming planet. Ward found that both extreme high heat conditions as well as a relatively rapid pace of warming, in geological terms, increased the speed of transition to stratified ocean and Canfield Ocean states. Ward acknowledged that high rates of water runoff from continents likely contributed to anoxia. Recent studies have also indicated that rapid glacial melt combined with rapid global heating may contribute to a an increasingly stratified and anoxic ocean system.

Now, a new study of deep ocean corals entitled Increasing subtropical North Pacific Ocean nitrogen fixation since the Little Ice Age and conducted by researchers at the University of Santa Cruz and published in Nature has discovered proxy evidence that ocean stratification over the past 150 years advanced at the most rapid pace in at least the last 12,000 years. The study analyzed the sediment composition of coral growth layers to determine changes in ocean states since the 1850s. As the corals sucked up the dead bodies of micro-organisms over the past 1,000 years, the researchers were able to analyze what was happening to the cyanobacteria at the base of the food web.

What they found was that the bacteria increased their rate of nitrogen fixation by about 17 to 27 percent over the past 150 year period. And that this pace of change was ten times more rapid than that observed at the end of the Pliestocene and beginning of the Holocene 12,000 years ago.

Nitrogen Proxy Records and Their Relationship to Climate Change

(The Ocean’s Hockey Stick? Nitrogen Proxy Levels and Their Relationship to Climate Change.)

Increasing nitrogen fixation is an indicator of ocean stratification because cyanobacteria species under stress evolve to fix higher amounts of nitrogen from the surface transfer boundary with the air if particulate nitrogen levels in their environment drop. In a healthy, mixed ocean environment, nitrogen from various sources (terrestrial, run-off, etc), is readily traded between ocean layers due to the mixing action of ocean currents. In cooler oceans, more nitrogen is also held in suspension. But as oceans become warmer and more stratified, a loss of mixing and solubility results in lower nitrogen levels.

The researchers believe that this increase in nitrogen fixation is a clear indication that the region of the Pacific they observed is rapidly becoming more stratified and that this rate of increase is probably an order of magnitude faster than what occurred during the last major transition at the end of the last ice age.

“In comparison to other transitions in the paleoceanographic record, it’s gigantic,” Lead author Sherwood noted. “It’s comparable to the change observed at the transition between the Pleistocene and Holocene Epochs, except that it happens an order of magnitude faster.”

A separate study analyzing the nitrogen content of sea bird bones also provided proxy indication of a shift among cyanobacteria toward greater rates of nitrogen fixation, providing some additional confirmation for the increased ocean stratification observation. (An excellent article providing a more in depth exploration of these studies is available here.)

These studies combine with numerous observations of declining ocean health, increasing ocean hypoxia and anoxia, and an increasing number of observed mechanisms that may result in a more and more stratified ocean state as human warming intensifies to increase concern that the worst fears of Dr. Peter Ward and colleagues may be in the process of realization. (See: Dead Dolphins,  Climate Change Devastating Ocean Fishermen, and Mass Starfish Die-off for more indicators of failing ocean health.)

Concerned Journalists and Terrified Ecologists

Put into various contexts, the current state of climate and environmental health does channel our worst fears that the Permian Extinction event may well be in for a human-caused repeat. The current estimated background extinction rate of 100-250 species per day is possibly the most rapid in all of geological history. The current CO2 level, near 400 parts per million, is higher than at any time during which human beings walked the Earth. The pace of greenhouse gas emissions is at least six times faster than at any time in the geological record. And the current, very large, forcing provided by humans does not yet include a probable powerful and unpredictable response from the Earth’s natural systems.

As Ecologist Guy McPherson notes — Nature Bats Last. And we should not be comforted by this notion. Because Nature carries the biggest stick of all. A consequence hanging over our heads that grows larger and more dangerous with each passing year during which our insults to her continue.

Among the pessimists regarding the end consequences of human caused climate change and related pollution, ecologists are the worst of the bunch. This is likely due to the fact that ecologists are very intimately involved in the study of how communities of organisms succeed or fail in natural settings. Among all groups of scientists, they are perhaps the ones most intimately familiar with the way in which all living things are connected to both one another and to the natural world. Ecologists know all too well that small shifts can mean huge changes to biodiversity, the rate of death among living beings, and the distribution of species in a given environment. But the changes humans inflict are not small in the least. They roughly ripple through the natural world in ways that ecologists know all too well have never before been seen.

Dr. McPherson is such an ecologist and one with such great conscience and concern that he, years ago, abandoned most of the luxuries of modern civilization to live in a fashion that produced the least harm possible. Not that this action has resulted in more optimism on his part. In fact, Guy is one of a growing group of people who believe that no action is likely to save humankind. That our insults to the natural world have already grown too great.

McPherson notes:

“We’ve never been here as a species and the implications are truly dire and profound for our species and the rest of the living planet.”

In this observation, Guy is probably right. But I sincerely hope that his and my own worst fears do not emerge.

It was Guy’s ongoing tracking of various dangerous alterations to world climate systems and assertion that human extinction may well be nigh that drew the attention of prominent journalist Dahr Jamail. Jamail recently penned the article: “The Great Dying Redux: Shocking Parallels Between Ancient Mass Extinction and Climate Change.

Reading professor emeritus Guy McPherson’s blog was enough to convince Mr. Jamail of the risk that current warming could result in an extinction event to rival that of the Great Dying so long ago. Mr. Jamail notes:

It is possible that, on top of the vast quantities of carbon dioxide from fossil fuels that continue to enter the atmosphere in record amounts yearly, an increased release of methane could signal the beginning of the sort of process that led to the Great Dying. Some scientists fear that the situation is already so serious and so many self-reinforcing feedback loops are already in play that we are in the process of causing our own extinction. Worse yet, some are convinced that it could happen far more quickly than generally believed possible — even in the course of just the next few decades.

And so we come full circle. Rapid human warming leads to troubling ocean changes that hint at those feared to have resulted in mass extinctions during the Permian-Triassic boundary event. And the very rapid human warming puts at risk the catastrophically rapid release of Arctic methane which would certainly consign Earth to a rapid jump from a glacial to a hothouse state and potentially produce the kind of Canfield Oceans Dr. Ward fears. It is a deadly transition for which we have growing evidence with almost each passing day, one that McPherson and others fear could truly make an end to us and to so many other living creatures on this world.

So many scientists, so much valid reason to be dreadfully concerned, and yet we continue on the path toward a great burning never before seen in Earth’s history…

Links (Read them!):

A Deadly Climb From Glaciation to Hothouse: Why the Permian-Triassic Extinction is Pertinent to Human Warming

Increasing subtropical North Pacific Ocean nitrogen fixation since the Little Ice Age

The Great Dying Redux: Shocking Parallels Between Ancient Mass Extinction and Climate Change.

Deep Sea Corals Record Dramatic Long-Term Shift in Pacific Ocean Ecosystem

Nature Bats Last

Colorado Bob’s Climate Feed

Dead Dolphins

Mass Starfish Die-off

Climate Change Devastating Ocean Fishermen

NCAR A2 Model Run

Hat Tip to David Goldstein

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