- Global temperatures could rise by as much as eleven degrees
Celsius, according to one of the largest climate prediction projects ever
run.
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- This figure is twice the level that previous studies
have suggested.
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- The scientists behind the project, called climateprediction.net,
say it shows there's no such thing as a safe level of carbon dioxide.
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- The results of the study, which used PCs around the world
to produce data, are published in the journal Nature.
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- Climateprediction.net is run from Oxford University,
and is a distributed computing project; rather than using a supercomputer
to run climate models, people can download software to their own PCs, which
run the programs during downtime.
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- More than 95,000 people have registered, from more than
150 countries; their PCs have between them run more than 60,000 simulations
of future climate.
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- Each PC runs a slightly different computer simulation
examining what happens to the global climate if levels of carbon dioxide
in the atmosphere double from pre-industrial levels - which may happen
by the middle of the century.
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- What vary most between the simulations are the precise
nature of physical processes like the extent of convection within tropical
clouds - a process which drives the transport of heat around the world.
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- Lowest rise
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- So no two simulations will produce exactly the same results;
overall, the project produces a picture of the possible range of outcomes
given the present state of scientific knowledge.
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- The lowest rise which climateprediction.net finds possible
is two degrees Celsius, ranging up to 11 degrees.
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- The timescale would depend on how quickly the doubling
of CO2 was reached, but large rises would be on a scale of a century at
least from now.
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- "I think these results suggest that our need to
do something about climate change is perhaps even more urgent," the
climateprediction.net chief scientist David Stainforth told BBC News.
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- "However, with our current state of knowledge, we
can't yet define a safe level in the atmosphere."
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- On Monday, the International Climate Change Taskforce,
co-chaired by the British MP Stephen Byers, claimed it had shown that a
carbon dioxide concentration of over 400 ppm (parts per million) would
be 'dangerous'.
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- The current concentration is around 378 ppm, rising at
roughly 2ppm per year.
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- Dangerous warming
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- Next week the UK Meteorological Office hosts an international
conference, Stabilisation 2005, announced by Tony Blair late last year.
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- Its aim is to discuss what the term "dangerous"
global warming really means, and to look at ways to stabilise greenhouse
gas levels.
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- Myles Allen, the principal investigator of climateprediction.net,
said the focus on stabilisation might not be appropriate.
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- "Stabilisation as an exclusive target may not be
adequate," he told BBC News.
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- "Stephen Byers claims to know that 400 ppm is the
maximum 'safe' level; what we show is that it may be impossible to pin
down a safe level, and therefore we should not focus exclusively on stabilisation."
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- Distributed computing has been used before, notably by
the Search for Extra-Terrestrial Intelligence or Seti, where several million
people have downloaded software enabling them to analyse data from observations
of distant galaxies for signs of alien life.
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- The scientists behind climateprediction.net believe their
project, because it is distributed to individual PCs, can help inform people
about climate change - and that, in turn could bring political change.
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- "It's very difficult to get politicians to collaborate,
not only across the globe but also over sustained lengths of time,"
Bob Spicer from the Earth Sciences Department at the Open University, told
BBC News.
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- "The people who can hold politicians to account
are the public; and with this project we are bringing cutting-edge science
to the stakeholders, the public."
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- © BBC MMV
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- http://news.bbc.co.uk/2/hi/science/nature/4210629.stm
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