Nature Bats Last – Feedback Loops
Self-Reinforcing Feedback Loops (Part 2 of 3)
by Guy McPerson
guymcpherson.com
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Updated most recently, likely for the final time, 2 August 2016.
Self-Reinforcing Feedback Loops (also see analysis here)
1. This description combines sub-sea permafrost and methane hydrates in the Arctic. The two sources of methane are sufficiently similar to warrant considering them in combination. MSNBC knew about methane release from beneath the Arctic Ocean in 2007. Oddly, they seem to be ignorant about it today. And note that award-winning journalist Dahr Jamail’s reporting about methane registered at spot #6 on Project Censored’s 2014 compilation.
About 250 plumes of methane hydrates are escaping from the shallow Arctic seabed, likely as a result of a regional 1 C rise in temperature, as reported in the 6 August 2009 issue of Geophysical Research Letters. Methane bubbling out the Arctic Ocean is further elucidated in Science in March 2010. As described in a subsequent paper in the June 2010 issue of Geophysical Research Letters, a minor increase in temperature would cause the release of upwards of 16,000 metric tons of methane each year. Storms accelerate the release, according to research published in the 24 November 2013 issue of Nature Geoscience The latter paper also concludes the East Siberian Arctic Shelf is venting at least 17 teragrams of the methane into the atmosphere each year, up from 0.5 teragrams just 7 years earlier (a teragram is equal to 1 million tons). According to NASA’s CARVE project, these plumes were up to 150 kilometers across as of mid-July 2013. Global-average temperature is expected to rise by more than 4 C by 2030 and 10 C by 2040 based solely on methane release from the Arctic Ocean, according to Sam Carana’s research (see especially Image 24). Whereas Malcolm Light’s 9 February 2012 forecast of extinction of all life on Earth by the middle of this century appeared premature because his conclusion of exponential methane release during summer 2011 was based on data subsequently revised and smoothed by U.S. government agencies, subsequent information — most notably from NASA’s CARVE project — indicates the grave potential for catastrophic release of methane. (I doubt industrial civilization manages to kill all life on Earth, although that clearly is the goal.) Catastrophically rapid release of methane in the Arctic is further supported by Nafeez Ahmed’s thorough analysis in the 5 August 2013 issue of the Guardian as well as Natalia Shakhova’s 29 July 2013 interview with Nick Breeze (note the look of abject despair at the eight-minute mark). The 16 August 2013 issue of Geophysical Research Letters includes a report of the Siberian Kara Sea where “Arctic shelf region where seafloor gas release is widespread suggests that permafrost has degraded more significantly than previously thought.” In early November 2013, methane levels well in excess of 2,600 ppb were recorded at multiple altitudes in the Arctic. Later that same month, Shakhova and colleagues published a paper in Nature Geoscience suggesting “significant quantities of methane are escaping the East Siberian Shelf” and indicating that a 50-billion-tonne “burst” of methane could warm Earth by 1.3 C. Such a burst of methane is “highly possible at any time,” according to Shakhova in July 2013, which echoes findings from 2008 (paradoxically, on 23 May 2015 Shakhova said, “We never stated that 50 gigatonnes is likely to be released in near or distant future”). In the 7 September 2015 issue of Philosophical Transactions of the Royal Society A, Shakhova and colleagues concluded that “progression of subsea permafrost thawing and decrease in ice extent could result in a significant increase in CH4 emissions from the ESAS” (East Siberian Arctic Shelf).In the 7 September 2015 issue of Philosophical Transactions of the Royal Society A, Shakhova and colleagues concluded that “progression of subsea permafrost thawing and decrease in ice extent could result in a significant increase in CH4 emissions from the ESAS” (East Siberian Arctic Shelf). Taking an expectedly more conservative approach, Peter Wadhams expects a 0.6 C rise in global-average temperature within five years after an ice-free Arctic, more than sufficient to collapse civilization and enough to make Wadhams ponder human extinction.
By 15 December 2013, methane bubbling up from the seafloor of the Arctic Ocean had sufficient force to prevent sea ice from forming in the area. Nearly two years after his initial, oft-disparaged analysis, Malcolm Light concluded on 22 December 2013, “we have passed the methane hydrate tipping point and are now accelerating into extinction as the methane hydrate ‘Clathrate Gun’ has begun firing volleys of methane into the Arctic atmosphere.” According to Light’s analysis in late 2013, the temperature of Earth’s atmosphere will resemble that of Venus before 2100. The refereed journal literature tackles the topic of hothouse Earth with a paper in the 9 February 2016 issue of Nature Communications: “Water-rich planets such as Earth are expected to become eventually uninhabitable, because liquid water turns unstable at the surface as temperatures increase with solar luminosity. Whether a large increase of atmospheric concentrations of greenhouse gases such as CO2 could also destroy the habitability of water-rich planets has remained unclear. Here we show with three-dimensional aqua-planet simulations that CO2-induced forcing as readily destabilizes the climate as does solar forcing. The climate instability is caused by a positive cloud feedback and leads to a new steady state with global-mean sea-surface temperatures above 330 K” (330 Kelvin is about 57 C, compared to today’s temperature of about 15 C). Two weeks after Light’s 2013 analysis, in an essay stressing near-term human extinction, Light concluded: “The Gulf Stream transport rate started the methane hydrate (clathrate) gun firing in the Arctic in 2007 when its energy/year exceeded 10 million times the amount of energy/year necessary to dissociate subsea Arctic methane hydrates.” The refereed journal literature, typically playing catch-up with reality, includes an article in the 3 February 2014 issue of Journal of Geophysical Research: Earth Surface claiming, “Sustained submergence [of these sediments] into the future should increase gas venting rate roughly exponentially as sediments continue to warm.” Not surprisingly, the clathrate gun began firing in 2007, the same year the extent of Arctic sea ice reached a tipping point. Abundant evidence supporting the firing of the clathrate gun was collated and presented here on 9 September 2012. Further confirmation the clathrate gun had been fired came from Stockholm University’s Örjan Gustafsson, who reported from the Laptev Sea on 23 July 2014: “results of preliminary analyses of seawater samples pointed towards levels of dissolved methane 10-50 times higher than background levels.” Jason Box responds to the news in the conservative fashion I’ve come to expect from academic scientists on 27 July 2014: “What’s the take home message, if you ask me? Because elevated atmospheric carbon from fossil fuel burning is the trigger mechanism poking the climate dragon. The trajectory we’re on is to awaken a runaway climate heating that will ravage global agricultural systems leading to mass famine, conflict. Sea level rise will be a small problem by comparison.” Later, during an interview with Vice published 1 August 2014, Box loosened up a bit, saying, “Even if a small fraction of the Arctic carbon were released to the atmosphere, we’re fucked.” Trust me, Jason, we’re there.
Simultaneous with the Laptev Sea mission, several large holes were discovered in Siberia. The reaction from an article published in the 31 July 2014 issue of Nature indicates atmospheric methane levels more than 50,000 times the usual. An article in the 4 August 2014 edition of Ecowatch ponders the holes: “If you have ever wondered whether you might see the end of the world as we know it in your lifetime, you probably should not read this story, nor study the graphs, nor look at the pictures of methane blowholes aka dragon burps.”
One of the authors of two research papers rooted in the Siberian Kara Sea concluded on 22 December 2014, “If the temperature of the oceans increases by two degrees as suggested by some reports, it will accelerate the thawing to the extreme. A warming climate could lead to an explosive gas release from the shallow areas.” As we’ve known for a few years, 2 C is locked in.
By late February 2015, the Siberian crater saga had become “more widespread — and scarier — than anyone thought,” with numerous reports from the mainstream media. Naturally, these reports focused on economic impacts and the need for further research.
Methane release from thawing offshore permafrost was further verified with research reported in the 7 August 2015 issue of Journal of Geophysical Research. This paper, for the first time, describes pingo-like features beneath the seabed offshore from Siberia.
According to researchers quoted in the 22 September 2015 issue of The Siberian Times, the rare media outlet that is willing to address abrupt climate change in a meaningful manner, those massive craters on the Yamal Peninsula are, in fact, created by the release of methane. Furthermore, more craters are expected due to eruptions as permafrost continues to melt.
It turns out those giant, methane-emitting craters in the Yamal region of Siberia have subsea counterparts. A paper in the 7 August 2015 issue of Journal of Geophysical Research: Earth Science connects the craters on land with those in the adjacent, shallow South Kara Sea. According a write-up in The Siberian Times: “Large mounds — described as pingos — have been identified on the seabed off the Yamal Peninsula, and their formation is seen as due to the thawing of subsea permafrost, causing a ‘high accumulation’ of methane gas.”
The importance of methane cannot be overstated. Increasingly, evidence points to a methane burst underlying the Great Dying associated with the end-Permian extinction event, as pointed out in the 31 March 2014 issue of Proceedings of the National Academy of Sciences. As Malcolm Light reported on 14 July 2014: “There are such massive reserves of methane in the subsea Arctic methane hydrates, that if only a few percent of them are released, they will lead to a jump in the average temperature of the Earth’s atmosphere of 10 degrees C and produce a ‘Permian’ style major extinction event which will kill us all. Apparently a 5 C rise in global-average temperature was responsible for the Great Dying, according to Michael Benton’s book on the topic. In that case, the rise is temperature requires tens of thousands of years.
Discussion about methane release from the Arctic Ocean has been quite heated (pun intended). Paul Beckwith was criticized by the conservative website, Skeptical Science. His response from 9 August 2013 is here.
Robert Scribbler provides a terrifying summary 24 February 2014, and concludes, “two particularly large and troubling ocean to atmosphere methane outbursts were observed” in the Arctic Ocean. Such an event hasn’t occurred during the last 45 million years. Scribbler’s bottom line: “that time of dangerous and explosive reawakening, increasingly, seems to be now.”
Sam Carana includes the figure below in his 10 September 2014 analysis. Based on data from several reputable sources, exponential release of methane clearly is under way. Robert Scribbler reaches the conclusion, finally, on 8 December 2014.
A paper published in the 22 December 2015 online issue of the Proceedings of the National Academy of Sciences reports, “that emissions during the cold season (September to May) contribute ≥50% of annual sources of methane from Alaskan tundra, based on fluxes obtained from eddy covariance sites and from regional fluxes calculated from aircraft data. … The dominance of late season emissions, sensitivity to soil conditions, and importance of dry tundra are not currently simulated in most global climate models.”
2. Warm Atlantic water is defrosting the Arctic as it shoots through the Fram Strait (Science, January 2011). Extent of Arctic sea ice passed a tipping point in 2007, according to research published in the February 2013 issue of The Cryosphere. On 6 October 2012, Truth-out cites Peter Wadhams, professor of ocean physics at Cambridge University: “The Arctic may be ice-free in summer as soon as 2015. Such a massive loss would have a warming effect roughly equivalent to all human activity to date. In other words, a summer ice-free Arctic could double the rate of warming of the planet as a whole.” Subsequent melting of Arctic ice is reducing albedo, hence enhancing absorption of solar energy. According to NASA on 17 December 2014, “the rate of absorbed solar radiation in the Arctic in June, July and August has increased by five percent” since 2000. “Averaged globally, this albedo change is equivalent to 25% of the direct forcing from CO2 during the past 30 years,” according to research published in the 17 February 2014 issue of the Proceedings of the National Academy of Sciences. Destabilization of the deep circulation in the Atlantic Ocean may be “spasmodic and abrupt rather than a more gradual increase” as earlier expected, according to a paper published in the 21 February 2014 issues of Science. Models continue to underestimate results relative to observations, as reported in the 10 March 2014 issue of Geophysical Research Letters. Consider, for example, the thinning “by more than 50 metres since 2012 — about one sixth of its original thickness — and that it is now flowing 25 times faster,” as reported in the 23 December 2014 issue of Geophysical Research Letters. Rapid ice melt in the region is explained as a product of warm-air advection, air mass transformation, and fog in the June 2015 issue of Geophysical Research Letters.
3. Peat in the world’s boreal forests is decomposing at an astonishing rate (Nature Communications, November 2011)
4. Ozone, a powerful greenhouse gas, also contributes to mortality of trees (Global Change Biology, November 2011). Tree mortality reduces uptake of atmospheric carbon dioxide and instead accelerates the contribution of carbon dioxide into the atmosphere. Forest dieback resulting from atmospheric ozone is the primary topic addressed by Gail Zawacki at Wit’s End.
Analysis of tropospheric data has linked elevated levels of ozone with Indonesian forest fires, according to a paper in the 13 January 2016 issue of Nature Communications. Like methane, ozone is a potent but short-lived greenhouse gas. As indicated in the abstract: “This study suggest a larger role for biomass burning in the radiative forcing of climate in the remote TWP (Tropical Western Pacific) than is commonly appreciated.”
5. Invasion of tall shrubs warms the soil, hence destabilizes the permafrost (Environmental Research Letters, March 2012). Further elucidation of this phenomenon included study of 25 species, and ~42,000 annual growth records from 1,821 individuals, as reported in the 6 July 2015 online issue of Nature Climate Change.
6. Greenland ice is darkening (The Cryosphere, June 2012). As reported in the 8 June 2014 issue of Nature Geoscience, “a decrease in the albedo of fresh snow by 0.01 leads to a surface mass loss of 27 Gt” annually. Any reduction in albedo is a disaster, says Peter Wadhams, head of the Polar Oceans Physics Group at Cambridge University. As pointed out by Robert Scribbler on 1 August 2014, we’ve removed the plug and, like the water leaving a tub, acceleration is under way: “Extensive darkening of the ice sheet surface, especially near the ice sheet edge, is resulting in more solar energy being absorbed by the ice sheet. Recent studies have shown that edge melt results in rapid destabilization and speeds glacier flows due to the fact that edge ice traditionally acts like a wall holding the more central and denser ice pack back.” Jason Box registers his surprise with a photo essay on 29 October 2014. A paper in the 15 December 2014 issue of Proceedings of the National Academy of Sciences provides the first comprehensive picture of how Greenland’s ice is vanishing and concludes “that Greenland may lose ice more rapidly in the near future than previously thought.” Research reported in the 17 December 2015 issue of Nature calculates spatial ice mass loss around the entire Greenland Ice Sheet from 1900 to the present and finds “that many areas currently undergoing change are identical to those that experienced considerable thinning throughout the twentieth century.” According to one of paper’s co-authors “the average mass loss rate over the past decade is much larger than at any other time over the last 115 years.”
Adding to the rapidity of ice melt on Greenland is cloud cover. A paper published in the 12 January 2016 edition of Nature Communications shows that clouds are playing a larger role than previously understood in heating the Greenland Ice Sheet. Clouds trap heat, thus accounting for as much as 30% of the ongoing melt of the ice sheet.
According to a paper in the 3 March 2016 issue of The Cryosphere, the darkening of the Greenland ice sheet started becoming significantly less reflective of solar radiation from around 1996, with the ice absorbing 2% more solar energy per decade from this point. “Future darkening is likely underestimated,” according to the paper’s abstract.
7. Methane is being released from beneath Antarctic ice, too (Nature, August 2012). This third primary source of methane — in addition to permafrost and the shallow seabed — potentially is enormous. According to a paper in the 24 July 2013 issue of Scientific Reports, melt rate in the Antarctic has caught up to the Arctic and the West Antarctic Ice Sheet is losing over 150 cubic kilometres of ice each year according to CryoSat observations published 11 December 2013, and Antarctica’s crumbling Larsen-B Ice Shelf is poised to finish its collapse, according to Ted Scambos, a glaciologist at the National Snow and Ice Data Center at the annual meeting of the American Geophysical Union. A paper in the 12 September 2014 issue of Science concluded the major collapse of the Larsen-B Ice Shelf in 2002 resulted from warm local air temperatures, indicating the importance of global and local warming on ice dynamics. Two days later a paper in Nature Climate Change indicates that this sensitivity to temperature illustrates “that future increases in precipitation are unlikely to offset atmospheric-warming-induced melt of peripheral Antarctic Peninsula glaciers.” A study published in the 1 June 2015 issue of Earth and Planetary Science Letters finds the last remaining section of Antarctica’s Larsen B Ice Shelf, which partially collapsed in 2002, is quickly weakening and is likely to disintegrate completely before the end of the decade. Meanwhile, the Larsen-C Ice Shelf is poised to collapse, according to an article in the 13 May 2015 issue of The Cryosphere. A paper in the 8 February 2016 online issue of Nature Climate Change reinforces prior findings about the collapse of major ice shelves in Antarctica. Some of these country-sized, so-called “safety bands” are extremely dynamic and therefore susceptible to rapid breakup. The rate of loss during the period 2010-2013 was double that during the period 2005-2010, according to a paper in the 16 June 2014 issue of Geophysical Research Letters. By mid-May 2015 the sudden onset of ice loss in Antarctica was large enough to affect Earth’s gravity field, as reported in the 21 May 2015 issue of Science. According to NASA climate scientist Eric Rignot in early 2015, “the fuse is blown.” Rignot goes on to explain this “shattering” moment and also points out the utter ineptitude by climate scientists at explaining the situation to the public. According to research reported in the 26 March 2015 issue of Science, “West Antarctic losses increased by 70% in the last decade, and earlier volume gain by East Antarctic ice shelves ceased.” Loss of Antarctic ice is accelerating even in areas long considered stable, as documented in the 24 July 2013 edition of Scientific Reports. Based on gravity data published in the 1 April 2015 issue of Earth and Planetary Science Letters: “During the past decade, Antarctica’s massive ice sheet lost twice the amount of ice in its western portion compared with what it accumulated in the east, according to Princeton University researchers who came to one overall conclusion — the southern continent’s ice cap is melting ever faster.” The faster-than-expected narrative continued into 10 July 2015, when a paper in Science Advances found that geothermal activity was contributing to rapid melting of the West Antarctic Ice Sheet. The 14 March 2016 issue of Nature Geoscience includes a paper about Antarctic ice shelves concluding that “loss of ice shelf mass is accelerating, especially in West Antarctica, where warm seawater is reaching ocean cavities beneath ice shelves. … We conclude that basal channels can form and grow quickly as a result of warm ocean water intrusion, and that they can structurally weaken ice shelves, potentially leading to rapid ice shelf loss in some areas.” According to a paper in the 20 June 2016 issue of Nature Communications: “Here we report the discovery of a massive subsurface ice layer, at least 16 km across, several kilometres long and tens of metres deep, located in an area of intense melting and intermittent ponding on Larsen C Ice Shelf, Antarctica. We combine borehole optical televiewer logging and radar measurements with remote sensing and firn modelling to investigate the layer, found to be ~10 °C warmer and ~170 kg m−3 denser than anticipated in the absence of ponding and hitherto used in models of ice-shelf fracture and flow.” ** The Antarctic Peninsula is one of the fastest warming spots on the planet, and it was thought that the rising air temperature was driving the melt of the glaciers along its fringes. But it is actually warm ocean waters that are eating away at the ice along part of its western side, a group of scientists reported 15 July 2016 in the journal Science. ** Further confirmation of large methane releases is revealed by noctilucent clouds over the southern hemisphere from 21 November 2013 to 6 December 2013.
It’s not just Antarctica spewing methane hydrates from beneath the ice. Ice sheets may be hiding vast reservoirs in the Arctic, too, as reported in the 7 January 2016 issue of Nature Communications. As reported in the abstract, “recent dating of methane expulsion sites suggests that gas release has been ongoing over many millennia. Here we synthesize observations of ~1,900 fluid escape features — pockmarks and active gas flares — across a previously glaciated Arctic margin with ice-sheet thermomechanical and gas hydrate stability zone modelling. Our results indicate that even under conservative estimates of ice thickness with temperate subglacial conditions, a 500-m thick gas hydrate stability zone — which could serve as a methane sink — existed beneath the ice sheet. Moreover, we reveal that in water depths 150–520 m methane release also persisted through a 20-km-wide window between the subsea and subglacial gas hydrate stability zone. This window expanded in response to post-glacial climate warming and deglaciation thereby opening the Arctic shelf for methane release.”
8. Forest and bog fires are growing (in Russia, initially, according to NASA in August 2012), a phenomenon consequently apparent throughout the northern hemisphere (Nature Communications, July 2013). The New York Times reports hotter, drier conditions leading to huge fires in western North America as the “new normal” in their 1 July 2013 issue. A paper in the 22 July 2013 issue of the Proceedings of the National Academy of Sciences indicates boreal forests are burning at a rate exceeding that of the last 10,000 years. Los Alamos National Laboratory catches on during same month. According to reports from Canada’s Interagency Fire Center, total acres burned to date in early summer 2014 are more than six times that of a typical year. This rate of burning is unprecedented not just for this century, but for any period in Canada’s basement forest record over the last 10,000 years. A comprehensive assessment of biomass burning, published in the 21 July 2014 issue of Journal of Geophysical Research: Atmospheres, explains most of the global-average increase in temperature and explains that biomass burning causes much more global warming per unit weight than other human-associated carbon sources. By early August 2014 tundra fires were burning just 70 miles south of Arctic Ocean waters and the fires were creating their own weather via pyrocumulus clouds. According to a paper published in the 14 July 2015 issue of Nature Communications, the length of the fire season has increased nearly 20% since 1979.
Ignition sources are on the rise, too. According to a paper in the 14 November 2014 issue of Science, each 1 C rise in global-average temperature contributes to a 12 ± 5% increase in lightning strikes.
According to a paper in the 6 October 2015 online issue of the Proceedings of the National Academy of Sciences comes a paper describing how the 0.5 C rise in global-average temperature associated with the Medieval Climate Anomaly — commonly called the Medieval Warm period — contributed to substantial increase in area burned. According to the abstract: “Warming of ∼0.5 °C ∼1,000 years ago increased the percentage of our study sites burned per century by ∼260% relative to the past ∼400 y.”
According to a paper in the 16 March 2016 issue of Global Ecology and Biogeography, climate change is adversely altering the ability of Rocky Mountain forests to recover from wildfire. Specifically, warm, dry conditions in the years following fires impede the growth and establishment of vulnerable new post-fire seedlings. Not only does climate change contribute to more and larger fires in the region, thus killing the trees in the forest, but post-fire recruitment is reduced by the same conditions that contribute to the more and larger fires.
9. Cracking of glaciers accelerates in the presence of increased carbon dioxide (Journal of Physics D: Applied Physics, October 2012)
10. The Beaufort Gyre apparently has reversed course (U.S. National Snow and Ice Data Center, October 2012). Mechanics of this process are explained by the Woods Hole Oceanographic Institution here.
11. Exposure to sunlight increases bacterial conversion of exposed soil carbon, thus accelerating thawing of the permafrost (Proceedings of the National Academy of Sciences, February 2013). Subsequent carbon release “could be expected to more than double overall net C losses from tundra to the atmosphere,” as reported in the March 2014 issue of Ecology. Arctic permafrost houses about half the carbon stored in Earth’s soils, an estimated 1,400 to 1,850 petagrams of it, according to NASA, which is more than twice as much as already exists in the atmosphere. Peat chemistry changes as warming proceeds, which accelerates the process, as reported in the 7 April 2014 issue of Proceedings of the National Academy of Sciences.
12. The microbes have joined the party, too, according to a paper in the 23 February 2013 issue of New Scientist. A subsequent paper in the 22 October 2014 issue of Nature illustrates the key role of a single species of microbe in amplifying climate change.
13. According to a paper in the 12 April 2013 issue of Science, a major methane release is almost inevitable from permafrost in Alaska, which makes me wonder where the authors have been hiding. Almost inevitable, they report, regarding an ongoing event. Trees are tipping over and dying as permafrost thaws, thus illustrating how self-reinforcing feedback loops feed each other. A paper in the 6 April 2015 online issue of Nature concludes: “The heat production is not only expected to accelerate the organic carbon decomposition and potentially the amounts of carbon emitted to the atmosphere but could be the tipping point that will lead to the loss of evidence of early human history in the Arctic, which so far has been extremely well preserved in the top permafrost.” The rapidly decaying permafrost is largely recent in origin, according to a paper in the 27 April 2015 issue of Geophysical Research Letters, and is leading to a “runaway effect.” The resulting carbon is entering “the atmosphere at breakneck speed,” according to an analysis published in the 27 April 2015 issue of Geophysical Research Letters. A paper in the 1 February 2016 issue of the Journal of Geophysical Research: Biogeosciences finally indicates the scientific literature is catching up to the reality of the dire situation: “our results suggest that this subarctic tundra ecosystem is shifting away from its historical function as a C sink to a C source.” Slowly catching up to reality, a paper in the 12 March 2016 issue of Climate Change Responses indicates “the large stocks of carbon stored in graminoid soils should be more susceptible to mineralization in a warming Arctic.” In other words, climate warming accelerates carbon release from thawing Arctic soils.
A paper in the 20 June 2016 issue of Environmental Research Letters. According to the paper, permafrost thaw has risen fourfold in some Arctic regions during the last 50 years.
14. Summer ice melt in Antarctica is at its highest level in a thousand years: Summer ice in the Antarctic is melting 10 times quicker than it was 600 years ago, with the most rapid melt occurring in the last 50 years (Nature Geoscience, April 2013). According to a paper in the 4 March 2014 issue of Geophysical Research Letters — which assumes relatively little change in regional temperature during the coming decades — “modeled summer sea-ice concentrations decreased by 56% by 2050 and 78% by 2100” (Robert Scribbler’s in-depth analysis is here). Citing forthcoming papers in Science and Geophysical Research Letters, the 12 May 2014 issue of the New York Times reported: “A large section of the mighty West Antarctica ice sheet has begun falling apart and its continued melting now appears to be unstoppable. … The new finding appears to be the fulfillment of a prediction made in 1978 by an eminent glaciologist, John H. Mercer of the Ohio State University. He outlined the vulnerable nature of the West Antarctic ice sheet and warned that the rapid human-driven release of greenhouse gases posed ‘a threat of disaster.’” Although scientists have long expressed concern about the instability of the West Antarctic Ice Sheet (WAIS), a research paper published in the 28 August 2013 of Nature indicates the East Antarctic Ice Sheet (EAIS) has undergone rapid changes in the past five decades. The latter is the world’s largest ice sheet and was previously thought to be at little risk from climate change. But it has undergone rapid changes in the past five decades, signaling a potential threat to global sea levels. The EAIS holds enough water to raise sea levels more than 50 meters. According to a paper in the July 2014 issue of the same journal, the southern hemisphere’s westerly winds have been strengthening and shifting poleward since the 1950s, thus quickening the melt rate to the point of — you guessed it — “results that shocked the researchers.” A paper presented at the late 2014 meeting of the American Geophysical Union concludes, “comprehensive, 21-year analysis of the fastest-melting region of Antarctica has found that the melt rate of glaciers there has tripled during the last decade.” The 16 March 2015 online issue of Nature Geoscience adds to the misery and identifies melting from below Totten Glacier. Specifically, a paper published in the 19 May 2016 issue of Nature finds the Totten Glacier capable of “repeated large-scale retreat and advance,” with the researchers concluding the glacier is “fundamentally unstable.”
A paper in the 12 October 2015 issue of Nature Geoscience reports that the Antarctic ice is melting so fast that the stability of the whole continent could be at risk by 2100. No surprise about that long-into-the-future date, of course. But the paper uses two emissions scenarios to predict a doubling of surface melting of the ice shelves by 2050 and, with one emissions scenario, Antarctic ice shelves would be in danger of collapse by century’s end.
According to a paper in the 2 November 2015 online issue of the Proceedings of the National Academy of Sciences, “if the Amundsen Sea sector is destabilized, then the entire marine ice sheet will discharge into the ocean.” This appears to be admission of “self-sustained ice discharge from West Antarctica.”
According to a paper published in the 26 November 2015 issue of Nature Communications, “Outlet glaciers grounded on a bed that deepens inland and extends below sea level are potentially vulnerable to ‘marine ice sheet instability’. This instability, which may lead to runaway ice loss, has been simulated in models, but its consequences have not been directly observed in geological records. Here we provide new surface-exposure ages from an outlet of the East Antarctic Ice Sheet that reveal rapid glacier thinning occurred approximately 7,000 years ago, in the absence of large environmental changes. Glacier thinning persisted for more than two and a half centuries, resulting in hundreds of metres of ice loss.”
15. Increased temperature and aridity in the southwestern interior of North America facilitates movement of dust from low-elevation deserts to high-elevation snowpack, thus accelerating snowmelt, as reported in the 17 May 2013 issue of Hydrology and Earth System Sciences.
16. Floods in Canada are sending pulses of silty water out through the Mackenzie Delta and into the Beaufort Sea, thus painting brown a wide section of the Arctic Ocean near the Mackenzie Delta brown (NASA, June 2013). Pictures of this phenomenon are shown on this NASA website.
17. Surface meltwater draining through cracks in an ice sheet can warm the sheet from the inside, softening the ice and letting it flow faster, according to a study accepted for publication in the Journal of Geophysical Research: Earth Surface (July 2013). Further support for this idea was reported in the 29 September 2014 issue of Nature Communications. It appears a Heinrich Event has been triggered in Greenland. Consider the description of such an event as provided by Robert Scribbler on 8 August 2013:
In a Heinrich Event, the melt forces eventually reach a tipping point. The warmer water has greatly softened the ice sheet. Floods of water flow out beneath the ice. Ice ponds grow into great lakes that may spill out both over top of the ice and underneath it. Large ice damns (sic) may or may not start to form. All through this time ice motion and melt is accelerating. Finally, a major tipping point is reached and in a single large event or ongoing series of such events, a massive surge of water and ice flush outward as the ice sheet enters an entirely chaotic state. Tsunamis of melt water rush out bearing their vast floatillas (sic) of ice burgs (sic), greatly contributing to sea level rise. And that’s when the weather really starts to get nasty. In the case of Greenland, the firing line for such events is the entire North Atlantic and, ultimately the Northern Hemisphere.
Based on data collected in 2011, a paper published online in the 13 July 2015 issue of Nature Geoscience finds: “Given that the advection of warm, moist air masses and rainfall over Greenland is expected to become more frequent in the coming decades, our findings portend a previously unforeseen vulnerability of the Greenland ice sheet to climate change.” Briefly, melting of the “Greenland ice sheet has been shown to accelerate in response to surface rainfall and melt associated with late-summer and autumnal cyclonic weather events.”
18. Breakdown of the thermohaline conveyor belt is happening in the Antarctic as well as the Arctic, thus leading to melting of Antarctic permafrost (Scientific Reports, July 2013). In the past 60 years, the ocean surface offshore Antarctica became less salty as a result of melting glaciers and more precipitation, as reported in the 2 March 2014 issue of Nature Climate Change.
19. Loss of Arctic sea ice is reducing the temperature gradient between the poles and the equator, thus causing the jet stream to slow and meander (see particularly the work of Jennifer Francis, as well as this article in the 20 November 2014 issue of the Washington Post). The most extreme “dipole” on record occurred during 2013-2014, as reported in the Geophysical Research Letters. One result is the creation of weather blocks such as the recent very high temperatures in Alaska. This so-called “polar vortex” became widely reported in the United States in 2013 and received the attention of the academic community when the 2013-2014 drought threatened crop production in California. Extreme weather events are occurring, as reported in the 22 June 2014 issue of Nature Climate Change. Also called Rossby Waves, these atmospheric events are on the rise, as reported in the 11 August 2014 edition of the Proceedings of the National Academy of Science. A paper co-authored by Francis in the 6 January 2015 issue of Environmental Research Letters concludes with this line in the abstract: “These results suggest that as the Arctic continues to warm faster than elsewhere in response to rising greenhouse-gas concentrations, the frequency of extreme weather events caused by persistent jet-stream patterns will increase.” Regarding the Rossby Waves, a paper in the 24 April 2015 edition of Journal of Geophysical Research: Atmospheres includes this comment: “We also found a positive feedback mechanism resulting from the anomalous meridional circulation that cools the mid-latitudes and warms the Arctic, which adds an extra heating to the Arctic air column equivalent to about 60% of the direct surface heat release from the sea-ice reduction.” Francis’ work was further validated in the 31 August 2015 online issue of Nature Geoscience in an article titled, “Two distinct influences of Arctic warming on cold winters over North America and East Asia.”
As one result of the polar vortex, boreal peat dries and catches fire like a coal seam (also see this paper in Nature, published online 23 December 2014, indicating “the amount of carbon stored in peats exceeds that stored in vegetation and is similar in size to the current atmospheric carbon pool”). The resulting soot enters the atmosphere to fall again, coating the ice surface elsewhere, thus reducing albedo and hastening the melting of ice. Each of these individual phenomena has been reported, albeit rarely, but to my knowledge the dots have not been connected beyond this space. The inability or unwillingness of the media to connect two dots is not surprising, and has been routinely reported (recently including here with respect to climate change and wildfires) (July 2013)
20. Arctic ice is growing darker, hence less reflective (Nature Climate Change, August 2013)
21. Extreme weather events drive climate change, as reported in the 15 August 2013 issue of Nature (Nature, August 2013). Details are elucidated via modeling in the 6 June 2014 issue of Global Biogeochemical Cycles. Further data and explanation are presented in the 27 April 2015 online issue of Nature Climate Change.
“Explaining Extreme Events of 2014 from a Climate Perspective” was published by the Bulletin of the American Meteorological Society in their December 2015 issue and draws on conclusions from 32 international teams of scientists who investigated 28 separate weather events. Findings of this report, released on 5 November 2015, include the following: “Human activities, such as greenhouse gas emissions and land use, influenced specific extreme weather and climate events in 2014, including tropical cyclones in the central Pacific, heavy rainfall in Europe, drought in East Africa, and stifling heat waves in Australia, Asia, and South America.”
According to a paper in the 13 June 2016 issue of the Proceedings of the National Academy of Sciences, atmospheric aerosols strengthen storm clouds, thus leading to extreme weather. An abundance of aerosol particles in the atmosphere — constantly added via industrial activity — can increase the lifespans of large storm clouds by delaying rainfall, making the clouds grow larger and live longer, and producing more extreme storms.
For many years, scientists have cautioned that individual weather events couldn’t be attributed to climate change. Now, however, specific extreme weather events can be attributed to climate change. A 200-page, March 2016 report from the National Academies of Science, Engineering, and Medicine examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities.
22. Drought-induced mortality of trees contributes to increased decomposition of carbon dioxide into the atmosphere and decreased sequestration of atmospheric carbon dioxide. Such mortality has been documented throughout the world since at least November 2000 in Nature, with recent summaries in the February 2013 issue of Nature for the tropics, the August 2013 issue of Frontiers in Plant Science for temperate North America, and the <a href="http:/