New Study Makes Previous Climate Projections Look "Rosy"

The dire 2007 predictions of the U.N. Intergovernmental Panel on Climate Change (IPCC) painted a picture that was “a bit too rosy,” according to John Reilly, Ph.D., of the Massachusetts Institute of Technology (MIT), one of the authors of a new study suggesting that climate change is happening more rapidly than predicted.

It takes seven years to produce an IPCC report, which makes it difficult to accurately assess how rapidly changes are occurring, says the group of researchers from MIT, Penn State, the Marine Biological Institute, and the U.S. Environmental Protection Agency. The 2007 report assumed countries would achieve their pledged reductions in greenhouse gas emissions, but that hasn’t been the case: 2010 emissions exceeded IPCC projections by 10%. The new report forecasts a median global temperature increase of 9°F (6°C) by 2100—instead of IPCC’s predicted increase of 6.3°F (3.5°C)—along with greater sea-level rise, more extreme weather events, and up to three times greater Arctic warming. Even if countries do achieve the promised emissions reductions, say the authors, the global temperature increase will still exceed 7.2°F (5°C) by century’s end.