By Richard Gray, Science Correspondent, Sunday Telegraph
Last Updated: 1:08am GMT 11/02/2007



Man-made climate change may be happening at a far slower rate than has
been claimed, according to controversial new research.

Scientists say that cosmic rays from outer space play a far greater
role in changing the Earth's climate than global warming experts
previously thought.

In a book, to be published this week, they claim that fluctuations in
the number of cosmic rays hitting the atmosphere directly alter the
amount of cloud covering the planet.


High levels of cloud cover blankets the Earth and reflects radiated
heat from the Sun back out into space, causing the planet to cool.

Henrik Svensmark, a weather scientist at the Danish National Space
Centre who led the team behind the research, believes that the planet
is experiencing a natural period of low cloud cover due to fewer
cosmic rays entering the atmosphere.

This, he says, is responsible for much of the global warming we are
experiencing.

He claims carbon dioxide emissions due to human activity are having a
smaller impact on climate change than scientists think. If he is
correct, it could mean that mankind has more time to reduce our effect
on the climate.

The controversial theory comes one week after 2,500 scientists who
make up the United Nations International Panel on Climate Change
published their fourth report stating that human carbon dioxide
emissions would cause temperature rises of up to 4.5 C by the end of
the century.

Mr Svensmark claims that the calculations used to make this prediction
largely overlooked the effect of cosmic rays on cloud cover and the
temperature rise due to human activity may be much smaller.

He said: "It was long thought that clouds were caused by climate
change, but now we see that climate change is driven by clouds.

"This has not been taken into account in the models used to work out
the effect carbon dioxide has had.

advertisement"We may see CO2 is responsible for much less warming than
we thought and if this is the case the predictions of warming due to
human activity will need to be adjusted."

Mr Svensmark last week published the first experimental evidence from
five years' research on the influence that cosmic rays have on cloud
production in the Proceedings of the Royal Society Journal A:
Mathematical, Physical and Engineering Sciences. This week he will
also publish a fuller account of his work in a book entitled The
Chilling Stars: A New Theory of Climate Change.

A team of more than 60 scientists from around the world are preparing
to conduct a large-scale experiment using a particle accelerator in
Geneva, Switzerland, to replicate the effect of cosmic rays hitting
the atmosphere.

They hope this will prove whether this deep space radiation is
responsible for changing cloud cover. If so, it could force climate
scientists to re-evaluate their ideas about how global warming occurs.

Mr Svensmark's results show that the rays produce electrically charged
particles when they hit the atmosphere. He said: "These particles
attract water molecules from the air and cause them to clump together
until they condense into clouds."

Mr Svensmark claims that the number of cosmic rays hitting the Earth
changes with the magnetic activity around the Sun. During high periods
of activity, fewer cosmic rays hit the Earth and so there are less
clouds formed, resulting in warming.

Low activity causes more clouds and cools the Earth.

He said: "Evidence from ice cores show this happening long into the
past. We have the highest solar activity we have had in at least 1,000
years.

"Humans are having an effect on climate change, but by not including
the cosmic ray effect in models it means the results are
inaccurate.The size of man's impact may be much smaller and so the man-
made change is happening slower than predicted."

Some climate change experts have dismissed the claims as "tenuous".

Giles Harrison, a cloud specialist at Reading University said that he
had carried out research on cosmic rays and their effect on clouds,
but believed the impact on climate is much smaller than Mr Svensmark
claims.

Mr Harrison said: "I have been looking at cloud data going back 50
years over the UK and found there was a small relationship with cosmic
rays. It looks like it creates some additional variability in a
natural climate system but this is small."

But there is a growing number of scientists who believe that the
effect may be genuine.

Among them is Prof Bob Bingham, a clouds expert from the Central
Laboratory of the Research Councils in Rutherford.

He said: "It is a relatively new idea, but there is some evidence
there for this effect on clouds."

Earl Evleth wrote:

> In a book, to be published this week

So why did they publish a book instead of a peer reviewed scientific
paper? You need to go out and buy this book right way! Hurry up!

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