Saturday, August 18, 2007

Sun spots and climate change

The first-ever study to find a statistically significant linkage between sunspot activity and global temperature oscillations has important implications for climate change.
First, the effect of the sunspot cycle on global temperatures was greater than previously assumed, but still maxes out at 0.2 degrees C. Sorry, nay-sayers, the sun isn’t doing it.
And we’re at the minimum of the 11-year cycle – so while global temps have been seriously rising the last half-decade, the sun’s contribution has actually been diminishing (I know, its hard to talk about climate change over such small intervals, but hey, its been really, really hot!). Forecast – global warming ratchets up a notch the next six years as increasing solar energy adds to the problem.

Second, the study provides tangible backing to one major prediction of climate models: higher temperature variability at the poles. Since solar energy is much more variable at the equator, the polar variability must be due to something else – like melting ice feedback loops.

Finally the study gives us the first direct measure of the key climate model parameter “climate sensitivity”. This parameter drives climate model predictions because it is the estimate of the connection between climate change and the actual warming of the planet. The bad news: the measured value is higher than model-derived estimates being currently used. This means that the low-end of global warming predictions are “unlikely.”

Bearing in mind that the most quoted/published estimates of the future perils of climate changes are from the IPCC’s “consensus” (read: conservative) documents, I expect that this is one in a string of past and future studies showing that we should have been much, much more afraid….