warming has finally been explained: the Earth is getting hotter because
the Sun is burning more brightly than at any time during the past 1,000
years, according to new research.
A study by Swiss
and German scientists suggests that increasing radiation from the sun
is responsible for recent global climate changes.
Sami Solanki, the director of the renowned Max Planck Institute for
Solar System Research in Gottingen, Germany, who led the research,
said: "The Sun has been at its strongest over the past 60 years and may
now be affecting global temperatures.
Sun is in a changed state. It is brighter than it was a few hundred
years ago and this brightening started relatively recently - in the
last 100 to 150 years."
Dr Solanki said that the
brighter Sun and higher levels of "greenhouse gases", such as carbon
dioxide, both contributed to the change in the Earth's temperature but
it was impossible to say which had the greater impact.
Average global temperatures have increased
by about 0.2 deg Celsius over the past 20 years and are widely believed
to be responsible for new extremes in weather patterns. After pressure
from environmentalists, politicians agreed the Kyoto Protocol in 1997,
promising to limit greenhouse gas emissions between 2008 and 2012.
Britain ratified the protocol in 2002 and said it would cut emissions
by 12.5 per cent from 1990 levels.
Globally, 1997, 1998 and 2002 were the hottest years since worldwide weather records were first collated in 1860.
scientists agree that greenhouse gases from fossil fuels have
contributed to the warming of the planet in the past few decades but
have questioned whether a brighter Sun is also responsible for rising
To determine the Sun's role in
global warming, Dr Solanki's research team measured magnetic zones on
the Sun's surface known as sunspots, which are believed to intensify
the Sun's energy output.
The team studied sunspot
data going back several hundred years. They found that a dearth of
sunspots signalled a cold period - which could last up to 50 years -
but that over the past century their numbers had increased as the
Earth's climate grew steadily warmer. The scientists also compared data
from ice samples collected during an expedition to Greenland in 1991.
The most recent samples contained the lowest recorded levels of
beryllium 10 for more than 1,000 years. Beryllium 10 is a particle
created by cosmic rays that decreases in the Earth's atmosphere as the
magnetic energy from the Sun increases. Scientists can currently trace
beryllium 10 levels back 1,150 years.
Dr Solanki does not know what is causing the Sun to burn brighter now or how long this cycle would last.
says that the increased solar brightness over the past 20 years has not
been enough to cause the observed climate changes but believes that the
impact of more intense sunshine on the ozone layer and on cloud cover
could be affecting the climate more than the sunlight itself.
Bill Burrows, a climatologist and a member of the Royal Meteorological
Society, welcomed Dr Solanki's research. "While the established view
remains that the sun cannot be responsible for all the climate changes
we have seen in the past 50 years or so, this study is certainly
significant," he said.
"It shows that there is
enough happening on the solar front to merit further research. Perhaps
we are devoting too many resources to correcting human effects on the
climate without being sure that we are the major contributor."
David Viner, the senior research scientist at the University of East
Anglia's climatic research unit, said the research showed that the sun
did have an effect on global warming.
however, that the study also showed that over the past 20 years the
number of sunspots had remained roughly constant, while the Earth's
temperature had continued to increase.
suggested that over the past 20 years, human activities such as the
burning of fossil fuels and deforestation had begun to dominate "the
natural factors involved in climate change", he said.
Gareth Jones, a climate researcher at the Met Office, said that Dr
Solanki's findings were inconclusive because the study had not
incorporated other potential climate change factors.
Sun's radiance may well have an impact on climate change but it needs
to be looked at in conjunction with other factors such as greenhouse
gases, sulphate aerosols and volcano activity," he said. The research
adds weight to the views of David Bellamy, the conservationist. "Global
warming - at least the modern nightmare version - is a myth," he said.
"I am sure of it and so are a growing number of scientists. But what is
really worrying is that the world's politicians and policy-makers are
"Instead, they have an unshakeable faith in
what has, unfortunately, become one of the central credos of the
environmental movement: humans burn fossil fuels, which release
increased levels of carbon dioxide - the principal so-called greenhouse
gas - into the atmosphere, causing the atmosphere to heat up. They say
this is global warming: I say this is poppycock."