The last year or so has seen more scientific papers and presentations that raise the genuine prospect of catastrophe (if we stay on our current emissions path) that I can recall seeing in any other year.
Perhaps the media would have ignored that science anyway, but Climategate appears to be a key reason “less than 10 percent of the news articles written about last year’s climate summit in Copenhagen dealt primarily with the science of climate change, a study showed on Monday.”
But for those interested in the real climate science story of the past year, let’s review a couple dozen studies of the most important findings. Any one of these would be cause for action — and combined they vindicate the final sentence of Elizabeth Kolbert’s Field Notes from a Catastrophe: “It may seem impossible to imagine that a technologically advanced society could choose, in essence, to destroy itself, but that is what we are now in the process of doing.”
1. Nature: “Global warming blamed for 40% decline in the ocean’s phytoplankton”: “Microscopic life crucial to the marine food chain is dying out. The consequences could be catastrophic.”
If confirmed, it may represent the single most important finding of the year in climate science. Seth Borenstein of the AP explains, “plant plankton found in the world’s oceans are crucial to much of life on Earth. They are the foundation of the bountiful marine food web, produce half the world’s oxygen and suck up harmful carbon dioxide.” Boris Worm, a marine biologist and co-author of the study said, “We found that temperature had the best power to explain the changes.” He noted, “If this holds up, something really serious is underway and has been underway for decades. I’ve been trying to think of a biological change that’s bigger than this and I can’t think of one.”
2. Science: Vast East Siberian Arctic Shelf methane stores destabilizing and venting: NSF issues world a wake-up call: “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.”
Methane release from the not-so-perma-frost is the most dangerous amplifying feedback in the entire carbon cycle. This research finds a key “lid” on “the large sub-sea permafrost carbon reservoir” near Eastern Siberia “is clearly perforated, and sedimentary CH4 [methane] is escaping to the atmosphere.”
The permafrost permamelt contains a staggering “1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere,” much of which would be released as methane. Methane is is 25 times as potent a heat-trapping gas as CO2 over a 100 year time horizon, but 72 times as potent over 20 years!
The carbon is locked in a freezer in the part of the planet warming up the fastest (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“). Half the land-based permafrost would vanish by mid-century on our current emissions path (see “Tundra, Part 2: The point of no return” and below). No climate model currently incorporates the amplifying feedback from methane released by a defrosting tundra.
The NSF is normally a very staid organization. If they are worried, everybody should be.
It is increasingly clear that if the world strays significantly above 450 ppm atmospheric concentrations of carbon dioxide for any length of time, we will find it unimaginably difficult to stop short of 800 to 1000 ppm.
3. Must-read NCAR analysis warns we risk multiple, devastating global droughts even on moderate emissions path.
Dust-Bowlification may be the impact of human-caused climate change that hits the most people by mid-century, as the figure below suggests (“a reading of -4 or below is considered extreme drought”):
The PDSI in the Great Plains during the Dust Bowl apparently spiked very briefly to -6, but otherwise rarely exceeded -3 for the decade (see here). The National Center for Atmospheric Research notes “By the end of the century, many populated areas, including parts of the United States, could face readings in the range of -8 to -10, and much of the Mediterranean could fall to -15 to -20. Such readings would be almost unprecedented.”
Read the rest at Climate Progress and share it broadly...