Tropical forests may dry out
and become vulnerable to devastating wildfires
as global warming accelerates over the coming
decades, a senior scientist has warned.
Soaring greenhouse gas emissions,
driven by a surge in coal use in countries such
as China and India, are threatening temperature
rises that will turn damp and humid forests
into parched tinderboxes, said Dr. Chris Field,
co-chair of the UN's Noble prize-winning Intergovernmental
Panel on Climate Change (IPCC).
Wildfires
Higher temperatures could see
wildfires raging through the tropics and a large-scale
melting of the Arctic tundra, releasing billons
of tones of carbon into the atmosphere that
will accelerate warming even further, he said.
Field said that the IPCC's
last report on climate change in 2007 had substantially
underestimated the severity of global warming
over the rest of the century.
The report concluded that the
earth's temperature is likely to rise between
1.1C and 6.4C by 2100, depending on future global
carbon emissions.
Tipping
point
Field said that if the tropics
became dry enough for fires to break out, tropical
forests would pass a "tipping point"
from absorbing carbon dioxide from the atmosphere
to releasing it. "Tropical forests are
essentially not flammable. You couldn't get
a fire to burn there if you tired. But if they
dry out just a little, the result can be very
large and destructive wildfires.
It is increasing clear that
as you produce a warmer world, lots of forested
areas that had been acting as carbon sinks could
be converted to carbon sources," he said.
The result could lead to runway warming.-Guardian
Newspapers Limited 2009.
