The Sunday Times March 26, 2006
Brighter sun adds to fears of climate change
http://www.timesonline.co.uk/article/0,,2087-2104022,00.html

THE amount of sunshine reaching earth is increasing, accelerating the
pace of climate change, scientists have found.
A series of independent studies around the world show a significant
rise in the amount of sunshine penetrating the atmosphere to be
absorbed by the earth's surface and turned into heat.

The research will concern climate researchers who are already
predicting a rapid rise in global temperatures due to man-made
emissions of so-called greenhouse gases such as carbon dioxide.

"The enhanced warming we have seen since the 1990s along with
phenomena such as the widespread melting of glaciers could well be due
to this increased intensity of sunlight compounding the effect of
greenhouse gases," said Professor Martin Wild of the Institute of
Atmospheric and Climate Science in Zurich, Switzerland.

Researchers will present their findings to the European Geophysical
Union conference in Vienna next week.

They reverse a 30-year trend. Measurements of sunshine levels between
1960 and 1990 had shown a decrease in the amount of sunshine reaching
the earth, a phenomenon known as global dimming.

This was thought to have been caused by dust, smog and other
pollutants, mainly from industrialised western countries.The
pollutants, known as aerosols, reduced sunshine levels by absorbing
and scattering solar radiation and promoting the formation of clouds
that reflected radiation back into space.

In the last two decades, however, there have been significant
decreases in such pollutants, partly due to industry becoming cleaner
but largely because of the collapse of the Soviet Union and much of
its heavy industry.

Wild said: "Sunshine levels had been decreasing by 2% a decade between
1960 and 1980 - a total decline of about 6%. Now they are going up
again. Perhaps this is why our Swiss glaciers are melting."

A 6% increase in the amount of solar radiation reaching earth would
have a powerful impact on climate, especially when added to the
warming effect of greenhouse gases which have already raised global
temperatures by about 0.6C. Researchers predict an additional rise of
at least 1.5C by 2050.

Such rises could be disastrous for agriculture, wildlife and human
settlements in many regions, especially the tropics. But scientists
warn they may have to revise these calculations sharply upwards if the
impact of "global brightening" has to be factored in.

Atsumu Ohmura, of the Swiss Federal Institute of Technology in Zurich,
has collated measurements from 400 sites worldwide and found an
increase in sunshine at 300 of them, sited mainly in Eurasia and the
Polar regions.

Some showed a decline in sunshine since 1990, largely in
fast-developing countries such as China and India.

"A widespread brightening has been observed since the 1980s. This may
substantially affect surface climate, the water cycle, glaciers and
ecosystems," said Ohmura.

--
"There are no absolute certainties in this universe. A man must try to
whip order into a yelping pack of probabilities, and uniform success is
impossible." -- Jack Vance

"Civilizaton is the interval between Ice Ages." -- Will Durant.

"War is God's way of teaching Americans geography" -- Ambrose Bierce

"Long term commitment in relationships is only necessary because it takes
so damn long to raise children. Marriage may well be some kind of trick
to keep the males around beyond sexual satiation." -- Captain Compassion

"Progress is the increasing control of the environment by life.
--Will Durant

Joseph R. Darancette
daranc@NOSPAMverizon.net