DISAPPEARANCE…. TIED TO GLOBAL WARMING

[Anonymous]

Frogs’ Disappearance Tied to Warming
(Jan.
06) – A team of biologists and climate scientists says in a new study
that it has linked the extinction of a widespread group of animals to
global warming.
Writing in Thursday’s issue of the journal Nature,
the scientists say that more than 60 closely related frog and toad
species have vanished from the tropical forests of Latin America during
the last few decades, partly because of warming temperatures. The team
says this is the first time such a connection has been made.
The
research team found a “near lock-step (link) between the timing of
losses and changes in climate,” said lead scientist Alan Pounds of the
Monteverde Cloud Forest Preserve and Tropical Science Center in Costa
Rica. “It’s a very striking pattern, and it’s hard to find another
explanation for it.”
The group did not identify the other
contributing causes. Pounds and his team say the warmer temperatures of
the late 20th century led to better growing conditions for a fungus
that kills frogs and toads.
Other scientists expressed skepticism
about the findings. Stephen Corn of the U.S. Geological Survey said the
dates recorded for extinctions may not be entirely reliable. The
University of Colorado’s Cynthia Carey questioned why the new work
ignores extinctions of related species after 1998.
The Earth’s
average temperature rose roughly 1 degree in the 20th century and could
rise 10 more degrees by 2100, according to an international group of
scientists convened by the United Nations.
That group and other
researchers attribute the warming trend to the use of coal, oil and
other fossil fuels, which emit carbon dioxide when burned. Buildup of
the gas in the atmosphere can trap heat.
Scientists already have
evidence linking higher temperatures to changes in the behavior or
range of hundreds of species, such as flowers that bloom earlier in the
year.
Scientists in the U.N. group predicted in 2001 that global
warming would produce a wave of extinctions. They did not predict
they’d see evidence so quickly.
“None of us expected that we’d be
seeing massive extinctions in five years,” said Camille Parmesan of the
University of Texas. She was not on the Pounds team but found the link
between extinction and global warming “very convincing.”
Pounds and
his colleagues compared when a species was last seen with climate data.
They found that roughly 80% of the extinct species were spotted for the
last time just after a particularly hot year. For example, the
Monteverde harlequin frog hasn’t been seen since 1988, one year after a
warm year.
Pounds and his team theorize that the changes in the
region’s climate are encouraging the growth of a parasite that spread
around the world in the 1960s and is a known killer of frogs and toads.
Pounds said more work needs to be done to nail down this possibility.

[Author]

January 12, 2006 at 10:46 AM