Insects offer clues to climate variability 10,000 years ago

[OKIsItJustMe]

http://news.illinois.edu/news/11/1114climate_FengShengHu.html

Insects offer clues to climate variability 10,000 years ago

11/14/2011 | Diana Yates, Life Sciences Editor | 217-333-5802; [e-mail]

CHAMPAIGN, lll. — An analysis of the remains of ancient midges – tiny non-biting insects closely related to mosquitoes – opens a new window on the past with a detailed view of the surprising regional variability that accompanied climate warming during the early Holocene epoch, 10,000 to 5,500 years ago.

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“This study shows that early Holocene warming did not occur everywhere in high latitudes, and exhibited important regional exceptions, even though the driving force behind it – solar input, in this case – was geographically uniform,” said Clegg, who is now a postdoctoral researcher in Hu’s lab. The drivers of climate change during the early Holocene “were different than the greenhouse gases responsible for global warming today,” Clegg said. “So we should not expect to see exactly the same spatial patterns of temperature anomalies in the next few decades as during the early Holocene.”

The researchers hypothesize that solar warming during the early Holocene spurred atmospheric circulation patterns that contributed to extensive sea-ice off the Alaskan coast. That, and a treeless tundra over more of the land area than at present would have increased surface reflectivity, potentially contributing to the observed cooling, Clegg said.

“This study has important ecological and societal implications,” Hu said. “Nonlinear responses such as those identified here constitute a major source of potential climate ‘surprises’ that make it more difficult to anticipate and prepare for future regional climate scenarios.”

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http://dx.doi.org/10.1073/pnas.1110913108