Repost: Earth losing fight against global warming
--- In ClimateArchive@yahoogroups.com, mtneuman@j... wrote:
> Earth `losing fight against global warming'
> > 07 August 2005
> By Jenifer Johnston
> THE Earth is losing its natural resistance to global warming as the
> oceans and forests reach capacity in their ability to soak up
> emissions, say scientists.
> Using a new computer model, researchers "fast- forwarded" 100
> reveal that unless emissions are curbed, land and seas
the "sinks" for
> carbon dioxide will become steadily less effective at removing
> from the atmosphere, causing the planet to heat faster and
> temperatures and droughts.
> Lead researcher Dr Inez Fung of the University of California,
> told the Sunday Herald the model debunks one argument put forward
> global-warming sceptics that plants will flourish and the oceans
> a warmer environment.
> "Our work shows that if we keep going on our current course of
> fuel emissions, the land and oceans will not be able to slow the
> carbon dioxide in the atmosphere the way they are doing now. Land
> oceans absorb about half of the carbon dioxide produced by human
> at the moment. If we accelerate our emissions, the saturation rate
> increase," she said.
> Fung's model suggests that as heat and droughts increase, plants
> their intake of carbon dioxide to save water. Ultimately, they stop
> absorbing it at all. Similarly, as the oceans heat up they
> absorb carbon dioxide which then collects near the surface, further
> preventing absorption and accelerating global warming.
> Using data from 1982 onwards, Fung said the northern hemisphere has
> "greened" each spring and summer as the climate has warmed,
> more atmospheric CO2 being absorbed by plants.
> However, since 1994, as droughts have made the world hotter and
> plants have been unable to cope. Even though plants could take in
> CO2 in spring, that has been offset by decreasing CO2 uptake during
> summers which have become increasingly dry, literally "browning"
> "We're saying `hold on a second plants may not be happier in a
> and drier world'. This negative effect of hot, dry summers
> wiped out the benefits of warm, wet springs. If you look at
> pictures of the Earth over this time you can actually see this
> now," Fung said.
> Fung's planet model predicts that by 2050 as the biosphere
> absorb CO2 being pumped into the atmosphere by humans burning
> fuels faster and faster the planet will not be able to keep up,
> that, at a low estimate, global temperatures will rise 1.4°C .
> "The Earth has a natural rate of absorption that you just cannot
> accelerate you can't make the land accept more CO2 just because
> being released," she said. "If the rate of fossil fuel emissions
> high, the carbon storage capacity of the land and oceans decreases
> climate warming accelerates."
> Last week the World Wildlife Federation warned that Scotland's
> temperature for 2005 is 1°C above average. Overall, Scotland's
> annual temperature has increased by 1°C in the past four decades.
> Friends of the Earth Scotland's Dr Dan Barlow warned: "It is not
> surprising that the Earth's ability to deal with rising carbon
> has limits and it is increasingly clear that we have a very narrow
> in which to act to avert climate chaos."
> Dr David Reay of the Institute of Atmospheric and Environmental
> at the University of Edinburgh said the study's predictions
> "As scientists we're aware that you cannot keep pumping CO2 into
> atmosphere and expect the Earth to keep absorbing it. This study
> important in terms of giving us a window on the future," he said.
> Fung, one of the world's leading climate scientists, has spent
> studying the carbon cycle of the planet, producing a sophisticated
> which takes into account the tiniest of details, such as the
> oceans and forest floor litter decomposition rates and the effects
> temperature, rainfall, clouds and wind speed on these kinds of
> She told the Sunday Herald: "The Earth is entering a climate space
> never seen before we don't know where the threshold is. You
> that a one or two degree increase is not all that much but if
> the threshold, it could make a big difference."
> 07 August 2005