麻豆AV

A new method for projecting how the temperature will respond to human impacts supports the outlook for substantial global warming throughout this century 鈥� but also indicates that, in many regions, warming patterns are likely to vary significantly from those estimated by widely used computer models.

The , outlined by 麻豆AV researchers in Geophysical Research Letters, is based on historical temperature increase in response to rising greenhouse gas concentrations and other climate influences. This approach could be used to complement the complex global climate models, filling a need for more reliable climate projections at the regional scale, the researchers say.

鈥淏y establishing a historical relationship, the new method effectively models the collective atmospheric response to the huge numbers of interacting forces and structures, ranging from clouds to weather systems to ocean currents,鈥� says Shaun Lovejoy, a 麻豆AV physics professor and senior author of the study.

鈥淥ur approach vindicates the conclusion of the Intergovernmental Panel on Climate Change (IPCC) that drastic reductions in greenhouse gas emissions are needed in order to avoid catastrophic warming,鈥� he adds. 鈥淏ut it also brings some important nuances, and underscores a need to develop historical methods for regional climate projections in order to evaluate climate-change impacts and inform policy.鈥�

In particular, the new approach suggests that for over 39% of the globe, the computer models either overestimate or underestimate significantly the pace of warming, according to Lovejoy and his co-author, PhD student Rapha毛l H茅bert (now at the Alfred-Wegener-Institut, in Potsdam.

These areas of significant difference are indicated by the x鈥檚 in the map above. For example, the map shows that the IPCC projections are expected to be too warm (red x鈥檚) over vast parts of the Pacific Ocean, the North Atlantic Ocean, and the Indian Ocean, while the opposite is true for the South Atlantic Ocean and the part of the Indian Ocean south of Australia.听 In contrast, the projected warming is expected to be underestimated (blue) over northwestern Canada and central Asia -- and a seasonal analysis reveals that this is primarily due to an underestimate of the warming in winter months.听 (Dark red indicates 3-degree Celsius model overestimate,听dark blue听3-degree underestimate if CO2 is doubled).

"," by H茅bert, R., and S. Lovejoy is published in Geophysical Research Letters.