Global Warming Threatens Extinctions
April 11, 2006 — By Alister Doyle, Reuters
OSLO — Global warming will become a
top cause of extinction from the tropical Andes to South Africa with thousands
of species of plants and animals likely to be wiped out in coming decades, a
study said on Tuesday.
"Global warming ranks among the most serious threats to the planet's
biodiversity and, under some scenarios, may rival or exceed that due to
deforestation," according to the study in the journal Conservation
Biology.
"This study provides even stronger scientific evidence that global warming
will result in catastrophic species loss across the planet," said Jay
Malcolm, an assistant forestry professor at the University of Toronto and a
lead author of the study with scientists in the United States and Australia.
Last month, a U.N. study said humans were responsible for the worst spate of
extinctions since the dinosaurs and urged unprecedented extra efforts to reach
a U.N. target of slowing the rate of losses by 2010.
Scientists disagree about how far global warming is to blame compared with
other human threats such as deforestation, pollution and the introduction of
alien species to new habitats.
The new study looked at 25 "hotspots" -- areas that contain a big
concentration of plants and animals -- and projected that 11.6 percent of all
species, with a range from 1-43 percent, could be driven to extinction if
levels of heat trapping-gases in the atmosphere were to keep rising in the next
100 years.
The range would mean the loss of thousands, or tens of thousands, of species.
The report gave a wide range because of uncertainties, for instance, about the
ability of animals or plants to move towards the poles if the climate warmed.
"Areas particularly vulnerable to climate change include the tropical
Andes, the Cape Floristic region (on the tip of South Africa), southwest
Australia, and the Atlantic forests of Brazil, Paraguay and Argentina," it
said.
NO ESCAPE
Species in many of these regions have limited escape routes. Rare plants,
antelopes, tortoises or birds found only on the southern tip of Africa, for
instance, cannot move south because the nearest land is thousands of miles away
in Antarctica.
The scientists said their study broadly backed the findings of a 2004 report in
the journal Nature that suggested global warming could commit a quarter of the
world's species to extinction by 2050. No one knows how many species are on
earth, with estimates ranging from 5-100 million.
"It isn't just polar bears and penguins that we must worry about any
more," said Lee Hannah, co-author of the study and senior fellow for
climate change at Conservation International in the United States.
"We used a completely different set of methods (from the Nature study) and
came up with similar results. All the evidence shows that there is a very
serious problem," he said.
Global warming is widely blamed on rising concentrations of carbon dioxide in
the atmosphere linked to emissions of gases from burning fossil fuels in cars,
factories and power plants.
The U.N.'s Kyoto Protocol obliges about 40 nations to cut emissions by at least
5.2 percent below 1990 levels by 2008-12.
President George W. Bush pulled the United States out in 2001, arguing that
Kyoto was too costly and wrongly excluded poor nations. Bush instead favours
big investments in new technology to break what he has called a U.S. addiction
to oil.
Source: Reuters