Generally, tipping points are only recognized as such in our rear view mirrors, when it’s already too late to do anything.
But ironically, it’s possible that the extreme winter weather -- the "Polar Vortex" -- we’ve experienced this season can help us both see and act on climate change, and its imminent tipping points, before it’s too late. According to Rutgers University climate scientist researcher, Jennifer Francis, the record-breaking cold temperatures we’ve experienced this winter are due to a wavy and elongated jet stream that has allowed frigid Arctic air to travel much farther south than usual. Her research is demonstrating that we’re seeing more of this kind of jet stream behavior because of the rapid warming and melting of the Arctic.
The planet has not known an ice-free Arctic for 3 million years. Within the next few years, however, this body will be ice-free in the summers, something that Professor Peter Wadhams, an Arctic expert at Cambridge University estimates "with 95 percent confidence" will occur by 2018. (Studies by U.S. Navy researchers indicate that this could take place as early as 2016.) Having measured Arctic ice for 40 years, Wadhams stated that "The fall-off in ice volume is so fast it is going to bring us to zero very quickly."
This event will have profound consequences for our climate, including the possibility of altering the jet stream and changing weather patterns in the years ahead. More ominously, the loss of Arctic sea ice would also mean the release of methane which has been trapped in methane hydrates (methane surrounded by ice) for centuries.
British scientist, John Nissen, who chairs the Arctic Methane Emergency Group, suggests that if summer sea ice loss passes "the point of no return" and "catastrophic Arctic methane feedbacks" kick in, we’ll be in an "instant planetary emergency."
Until recently, the enormous white surface of the Arctic sea ice has served to reflect solar radiation back into the atmosphere. But when the ice has been replaced by dark water the reverse action takes place. Solar radiation is absorbed, heating those waters, and the planet with it. This, in turn contributes to the melting of the Greenland Ice Sheet (raising sea levels), thawing of permafrost on tundra (releasing methane trapped in soil), and destabilization of the subsea permafrost, which would release methane.
Methane is a greenhouse gas that is 105 times more potent than CO2 per molecule, over a 20-year period, and 23 times as powerful as CO2 per molecule on a 100-year timescale. It plays a crucial role in climate change because it’s part of a positive feedback loop -- as the planet warms, more methane is released, and more methane emissions mean more global warming.
A complete loss of summer sea ice could potentially release huge amounts of Arctic methane that might lead to a catastrophic climate change event, possibly akin to the Permian extinction (also known as the "Great Dying") 252 million years ago that wiped out more than 90 percent of life on earth. According to a March 2010 Science report these hydrates contain the equivalent of 1,000 to 10,000 gigatons of carbon. Humanity has burned 240 gigatons since the industrial revolution began, which has already produced an .85-degree Celsius rise in temperature. Some scientists worry that the release of such quantities of methane could raise temperatures 4 to 6 degrees Celsius, well beyond the 2-degree Celsius threshold which it is generally agreed we cannot go without risking climate disaster.
A study published by Nature in its July 2013 issue suggested that a 50-gigaton "burp" of methane from permafrost thawing beneath the East Siberian Sea is "highly possible at any time." This would result in the equivalent of at least 1,000 gigatons of carbon dioxide being released into the atmosphere.
Another study published recently in Nature Geoscience reports that great plumes of methane are presently being observed bubbling up in the Siberian Sea. Twice as much methane is being released from the East Siberian Arctic shelf, a 2 million square kilometer area off the coast of Northern Siberia, as was previously thought. Its researchers found that at least 17 teragrams (one million tons) of methane are being released in the atmosphere each year.
Active and growing methane vents up to 150 kilometers across the Arctic permafrost have been observed by NASA scientists. In a June 2013 report, one scientist described this as "a bubbling as far as the eye can see in which the seawater looks like a vast pool of seltzer." Between 2010 and 2011, researchers found that methane vents had grown by 3,333 percent, from 30 centimeters across to 1 kilometer, reflecting the non-linear, exponential way the planet is responding to climate change.
The day after the Nature Geoscience study was released, a group of scientists published a report in the Proceedings of the National Academy of Sciences stating that the amount of methane being emitted in the U.S. both from oil and agricultural operations could be 50 percent greater than previous estimates. This is greatly exacerbated by the extreme extraction of unconventional fuels, a major source of methane.
Atmospheric and marine scientist, Ira Leifer, notes that "the Permian mass extinction was related to methane and is thought to be the key to what caused the extinction of most species on the planet."
Scientists believe that we’re currently in the midst of the planet’s sixth mass extinction, with between 150 and 200 species becoming extinct daily. This rate is 1,000 times greater than the "natural" extinction rate and may already be comparable to the speed and intensity of the Permian mass extinction.
Yes, the tipping point is right in front of us.
The Climate Change Café meets Tuesday, Feb. 25, at 6:15 p.m. in the Brooks Library.
Tim Stevenson is a community organizer with Post Oil Solutions and can be reached at 802.869.2141 and firstname.lastname@example.org.