The Copenhagen Diagnosis: Sobering Update on the Science  

Yale Environment 360 has an article on the latest climate research summary released in the lead up to the Copenhagen summit - The Copenhagen Diagnosis:
Sobering Update on the Science.

Ahead of talks in Copenhagen, a group of leading climate scientists has issued a new report summarizing the most recent research findings from around the world and concluding that scientists have underestimated the pace and extent of global warming. The report — titled “The Copenhagen Diagnosis” — finds that in several key areas observed changes are outstripping the most recent projections by the UN’s Intergovernmental Panel on Climate Change and warns that “there is a very high probability of the warming exceeding 2 °C unless global emissions peak and start to decline rapidly” within the next decade.

The report points to dramatic declines in Arctic sea ice, recent measurements that show a large net loss of ice from both Greenland and Antarctica, and the relatively rapid rise in global sea levels — 3.4 millimeters per year — as particular reasons for concern. Sea-level rise this century, it states, “is likely to be at least twice as large” as predicted by the most recent IPCC report, issued in 2007, with an upper limit of roughly two meters.

“Sea level is rising much faster and Arctic sea ice cover shrinking more rapidly than we previously expected,” Stefan Rahmstorf, department head at Germany’s Potsdam Institute for Climate Impact Research, said in a press release accompanying the report. “Unfortunately, the data now show us that we have underestimated the climate crisis in the past.”

According to the report, which was released today, there are several elements of the climate system that could reach a “tipping point” in coming decades if current emissions trends continue. The report notes that even at current greenhouse gas concentrations, it is already “very likely” that a “summer ice-free Arctic is inevitable.” The Greenland Ice sheet, too, the report warns, “may be nearing a tipping point where it is committed to shrink.”

The report’s 26 authors include scientists from Germany, France, Switzerland, Austria, Canada, the U.S., and Australia. Most were also authors of the last IPCC report, and donated their time to draft “The Copenhagen Diagnosis.” The University of New South Wales’ Climate Change Research Centre provided logistical support.