Tuesday, May 22, 2012
New paper finds Sun caused abrupt climate change 2,800 years ago
A paper recently published in Nature Geoscience finds that large changes in solar UV radiation induced amplified effects upon climate and abrupt climate change via the atmospheric circulation. The authors state, "We conclude that changes in atmospheric circulation amplified the solar signal and caused abrupt climate change about 2,800 years ago, coincident with a grand solar minimum." The IPCC dismisses solar effects upon climate by only looking at small changes in Total Solar Irradiance (TSI), while ignoring large [up to 20%] changes in solar UV within and between solar cycles. The paper identifies a new mechanism by which small changes in solar activity may have amplified effects upon climate, others being via ozone or clouds.
Posted by MS at 2:21 PM