Sun 'does not change climate'

Scientists say cosmic rays may affect past weather, not today.

Mike Lockwood, of Lutherford-Appleton Laboratories in the United Kingdom, said: "This should stop the controversy so far." He conducted a new study with Claus Froehlich from the World Radiation Center in Sweden.

This study reaffirms the fact that warming over the past 20-40 years cannot be due to the sun's activities.

 

Dr. Piers Forster

Dr. Lockwood began research in part because the television documentary called The Great Global Warming Swindle, played by British television channel C4 at the beginning of the year. The film mentioned the hypothesis of cosmic rays.

He told the BBC: "All the graphs they put out ended in 1980, and I know why, because these charts have the opposite result later. You can't ignore the data that you have. dislike."

Warming trend

The scientists' main approach in this study is simple: to understand the heat and cosmic ray intensity over the past 30-40 years, and compare these trends with the average surface temperature graph. the face of the earth. Earth temperature increased by about 0.4 degrees Celsius during this time.

Most of the years in the 10th century, the sun's heat increased.

But around 1985, this trend was reversed. The temperature of the sun decreases. However, during this time, the temperature increased rapidly, even faster, than the previous 100 years.

"This study reaffirms the fact that global warming over the past 20-40 years cannot be caused by the sun," said Dr Piers Forster from the University of Leeds, leading the Intergovernmental Research Group on Climate change (IPCC) says.

Scientists are measuring the frequency of the sun's rays (Photo: NASA)

Cosmic ray reduction

The IPCC's February preliminary report concluded that greenhouse gas emissions are 13 times larger than changes in solar temperatures for global warming. But the organization was criticized for not mentioning the cosmic ray hypothesis, along with other actors, by Henrik Svensmark and Eigil Friis - Christensen of the Danish National Space Center.

Their hypothesis is that cosmic rays help clouds form by providing tiny particles of what water vapor attaches to. In general, clouds cool the earth. During the sun's strong activity, cosmic rays are partially blocked by the sun's stronger magnetic fields. Clouds are melting and the earth heats up.

Mike Lockwood said: "I think cosmic rays affect the surface of clouds. It works in the sea air, where there is not much for steam to cling to. It can also have an important effect on. pre-industrial temperatures, but you can't apply this to what we are currently witnessing, because we're playing another game. "