Climate Change Already Here
By AFP
02 February , 2005
Agence France Presse
Evidence is growing that global warming
is already starting to disrupt the world's delicately-balanced climate
system, and the damage will reverberate for generations, a top science
conference was told.
"There is no
longer any doubt that the Earth's climate is changing," conference
chairman Dennis Tirpak said Tuesday.
"Globally,
nine of the past 10 years have been the warmest since records began
in 1861," he said. "Rising greenhouse gases are affecting
rainfall patterns and the global water cycle."
Tirpak singled out
the heatwave that gripped western Europe in 2003 as an example. Europe's
worst natural disaster in 50 years killed as many as 30,000 people and
inflicted an estimated 30 billion dollars (23 billion euros) in damage.
"Since the
1970s, climatic warming has increased the extent and frequency of droughts
over land," he said. "(...) Terrestrial ecological systems
are shifting and marine systems are changing, all with outcomes that
are difficult to predict."
In temperate parts
of Asia, "recurring incidence of floods and droughts is already
apparent," said Rajendra Pachauri, chairman of the Intergovernmental
Panel on Climate Change (IPCC), the UN's paramount scientific authority
on global warming.
British scientist
Chris Rapley said melting ice from Antarctica was already accounting
for at least 15 percent of the two-millimeter annual rise (0.06 inches)
in the global sea level due to warming.
In the Antarctic
peninsula, which juts north from the continent, there had been three
iceshelf breakups in the last 10 years, including the creation of the
Larsen B iceberg, a Luxembourg-sized behemoth that is the biggest floating
object in the world.
When these iceshelves
break off, that speeds up the flow of ice into the sea from coastal
glaciers, he said. The ice melted, adding to global sea levels, he said.
"It's like
a cork in a bottle," he said. "You remove the icesheet and
the glacial flow increases," he said.
If Antarctica melted,
that would boost global sea levels by some 120 meters (390 feet), if
past evidence from Earth's natural cycle of ice ages is a guide.
However, most of
Antarctica's ice is locked up in the Western Antarctica icesheet, and
temperatures there are somewhat cooler than before, said Rapley.
The conference,
hosted by Britain at its Met Office headquarters in this southwestern
English city, is tasked with coming up with a state-of-play assessment
about man-made global warming.
The phenomenon is
blamed on the unbridled burning of gas, coal and oil, the fuels that
powered industrialization.
They release into
the atmosphere carbon dioxide (CO2) and other gases that have been locked
in Earth's crust for millions of years.
This carbon pollution
traps the Sun, causing Earth's surface to heat, disrupting the ballet-like
interplay between three physical giants: sea, air and land.
One problem is that
even if pollution were slashed immediately, temperatures would continue
to rise because of the gas which has already been spewed into the atmosphere.
"The inertia
can carry the impacts, especially on sea level rise, for centuries,
if not for millennia," Pachauri said.
Sea levels rise
mainly because water expands as it is heated. The oceans are such vast
volumes of water that, once the warming starts, it takes a long time
for the process to stop.
That warning was
underscored by a study about the risk of a meltdown of the Greenland
icesheet, something that would raise global sea levels by seven meters
(22.75 feet) if it were lost completely.
The icesheet could
start to contract when local temperatures warm by more than 2.7 C (4.8
F) compared with the present.
"There is a
significant possibility that this trigger point will be reached in the
next few centuries," said Jason Lowe of Britain's Hadley Center
for Climate Prediction and Research.
Even if atmospheric
CO2 levels are eventually stabilized at quite modest concentrations,
sea levels will continue to rise "for more than 1,000 years,"
he said. "Deglaciation of Greenland may be irreversible."
Copyright 2005 AFP