Forests Absorb 20 Percent Of Fossil Fuel Emissions:
Study
Date: 19-Feb-09
Country: UK
Author: Michael Kahn
Forests Absorb 20 Percent Of Fossil Fuel Emissions: Study Photo: Guillermo
Granja
A view of the Kapawi river, in the Ecuadorean rainforest
of Kapawi, some 165 miles (266 kilometers) southwest of Quito October 20,
2008.
Photo: Guillermo Granja
LONDON - Tropical trees have grown bigger over the past 40 years and now
absorb 20 percent of fossil fuel emissions from the atmosphere, highlighting
the need to preserve threatened forests, British researchers said Wednesday.
Using data collected from nearly 250,000 trees in the world's tropical
forests over the past 40 years, their study found that tropical forests
across the world remove 4.8 billion metric tons of carbon dioxide emissions
each year.
"To get an idea of the value of the sink, the removal of nearly 5 billion
tons of carbon dioxide from the atmosphere by intact tropical forests, based
on realistic prices for a ton of carbon, should be valued at around 13
billion pounds per year," said Lee White, Gabon's chief climate change
scientist, who co-led the study, said in a statement.
The researchers do not know exactly why trees are getting bigger and mopping
up more carbon but they suspect that extra carbon dioxide in the atmosphere
may be acting like a fertilizer.
While nature has provided a free subsidy for dealing with carbon emissions,
it is one that won't last forever because trees can only grow so much
bigger, said Simon Lewis, an ecologist at the University of Leeds who led
the study.
"The trees are growing just a bit bigger but they make a big difference
because there are so many trees and half their mass is carbon," Lewis said
in a telephone interview.
"Our study gives us another reason why it is really important to conserve
tropical rain forests."
The U.N. Intergovernmental Panel on Climate Change estimates that human
activity produces 32 billion tons of carbon dioxide worldwide each year, but
only about 15 billion tons actually stays in the atmosphere and affects
climate change.
Human-produced greenhouse gases are blamed for warming temperatures, which
experts say will spark heat waves, droughts, more powerful storms, species
extinctions and higher sea levels.
Knowing what exactly what happens to the carbon dioxide pumped into the
atmosphere will help researchers better
understand future climate change, Lewis added.
The team analyzed data on 250,000 tree records collected from the world's
tropical forests over a 40-year period and found that the total mass of
trees -- which is mostly in their
trunks -- was getting bigger on average.
As a result, tropical forests absorb more carbon emissions and now make up
about half the world's land carbon sink, the researchers said in the journal
Nature.
"This is all about what is happening with the trees but we still don't know
what is happening with the soils," said Lewis, who noted that oceans absorb
about 8 billion tons of carbon dioxide each year.
(Editing by Will Dunham and Richard Williams)
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