Study: Ancient climate events not uniform

The remains of ancient insects can yield clues to the regional variability of climate warming experienced 10,000 to 5,500 years ago, U.S. researchers say. Scientists at the University of Illinois said an analysis of the remains of ancient midges -- tiny non-biting insects closely related to mosquitoes -- opens a new window into the early Holocene epoch's climate history. Working with researchers from the University of British Columbia, Illinois researchers analyzed the abundance and variety of midge larvae buried in lake sediments in Alaska, an Illinois release said Thursday. Since midges are highly sensitive to summer temperatures, changes in the abundance of different species over time gave the scientists a reliable marker of temperature fluctuations over the last 10,000 years, they said. The analysis offers the first detailed record of temperature variation over that period, they said. "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," researcher Benjamin Clegg said. "This study has important ecological and societal implications," geology Professor Feng Sheng Hu said. "Non-linear 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."