Cool Sun

Skeptics of the idea that global warming is a man-made phenomenon often claim that the sun is simply entering a period of increased activity and that our carbon dioxide emissions have little or no effect on matters. Not so, according to new research presented to the Royal Society:

But a new analysis of data on the sun's output in the last 25 years of the 20th century has firmly put the notion to rest. The data shows that even though the sun's activity has been decreasing since 1985, global temperatures have continued to rise at an accelerating rate.

The solar hypothesis was championed publicly in March by the controversial Channel 4 documentary The Great Global Warming Swindle.

The programme has been heavily criticised for distorting scientific data to fit the sceptic argument and Carl Wunsch, a professor of physical oceanography at MIT who featured in the programme, later said that he was "totally misled" by the film makers and that his comments were "completely misrepresented".

The new analysis is designed to counter the main alternative scientific argument put forward by the programme - that solar activity may be to blame for global warming.

"The temperature record is simply not consistent with any of the solar forcings that people are talking about," said lead author Mike Lockwood at the Rutherford Appleton Laboratory in Oxfordshire.