Sunday, February 28, 2010

Worth being reminded

This is not a new conclusion, but it would appear to be based on new modelling, and is worth bearing in mind:
The sun goes through an 11-year solar cycle during which its luminosity varies according to the number of sunspots appearing on its face. The normal cycle has a small effect on Earth's weather. But sometimes lulls in sunspot activity can last several decades, driving down the sun's luminosity to a "grand minimum". The Maunder minimum lasted from 1645 to 1715 and may have contributed to the little ice age.

Stefan Rahmstorf and Georg Feulner of the Potsdam Institute for Climate Impact Research in Germany modelled what would happen to temperatures on Earth if a grand minimum started now and lasted until 2100. They found that while temperatures would go down by as much as 0.3 °C, global warming would push up temperatures by 3.7 to 4.5 °C - more than negating any effect of a global minimum

No comments: