Wednesday, December 05, 2007

Keep watching the sun

Dr David Whitehouse, an astronomer and the author of 'The Sun: A Biography' writes in The Independent today that we might be about to enter a period of unusually low sun activity. Such periods, in the past, have been associated with low temperatures on planet Earth.

Some members of the Russian Academy of Sciences, Whitehouse writes, say we may be at the start of a period like that seen between 1790 and 1820, a minor decline in solar activity called the Dalton Minimum. They estimate that the Sun's reduced activity may cause a global temperature drop of 1.5C by 2020. This is larger than most sensible predictions of man-made global warming over this period.

This is something we must take seriously, Whitehouse adds. What happened in the 17th century is bound to happen again some time. Recent work studying the periods when our Sun loses its sunspots, along with data on other Sun-like stars that may be behaving in the same way, suggests that our Sun may spend between 10 and 25 per cent of the time in this state.

He moots that the lateness of the expected cycle of sunspots might even be the start of another Little Ice Age. If so, then our Sun might come to our rescue over climate change, mitigating mankind's influence and allowing us more time to act. It might even be the case that the Earth's response to low solar activity will overturn many of our assumptions about man's influence on climate change. We don't know. We must keep watching the sun.

I wonder if they are watching in Brussels.


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