* Reservoir of methane under East Siberian Sea
* Release could accelerate ice melting, global warming
* Risks include extreme weather, poorer health, lower crop
By Nina Chestney
LONDON, July 24 A release of methane in the
Arctic could speed the melting of sea ice and climate change
with a cost to the global economy of up to $60 trillion over
coming decades, according to a paper published in the journal
Researchers at the University of Cambridge and Erasmus
University in the Netherlands used economic modelling to
calculate the consequences of a release of a 50-gigatonne
reservoir of methane from thawing permafrost under the East
They examined a scenario in which there is a release of
methane over a decade as global temperatures rise at their
They also looked at lower and slower releases, yet all
produced "steep" economic costs stemming from physical changes
to the Arctic.
"The global impact of a warming Arctic is an economic
time-bomb," said Gail Whiteman, an author of the report and
professor of sustainability, management and climate change at
the Rotterdam School of Management, part of Erasmus University.
"In the absence of climate-change mitigation measures, the
model calculates that it would increase mean global climate
impacts by $60 trillion," said Chris Hope, a reader in policy
modelling at the Cambridge Judge Business School, part of the
University of Cambridge.
That approaches the value of the global economy, which was
around $70 trillion last year.
The costs could be even greater if other factors such as
ocean acidification were included, the study said, or reduced to
some $37 trillion if action is taken to lower emissions.
As much as 80 percent of the costs would likely be borne by
developing countries experiencing more extreme weather,
flooding, droughts and poorer health as the Arctic melt affects
the global climate, the paper said.
Methane is a greenhouse gas usually trapped as methane
hydrate in sediment beneath the seabed. As temperatures rise,
the hydrate breaks down and methane is released from the seabed,
mostly dissolving into the seawater.
But if trapped methane were to break the sea surface and
escape into the atmosphere, it could "speed up sea-ice retreat,
reduce the reflection of solar energy and accelerate the melting
of the Greenland ice sheet," the study said.
It said that could bring forward the date at which the
global mean temperature rise exceeds 2 degrees Celsius by
between 15 and 35 years - to 2035 if no action is taken to curb
emissions and to 2040 if enough action is taken to have a 50
percent chance of keeping the rise below 2 degrees.
Scientists have said the rise in global average temperatures
this century needs to stay below 2 degrees Celsius to prevent
devastating climate effects such as crop failure and melting
However, the International Energy Agency warned last month
that the world is on course for a rise of 3.6 to 5.3 degrees
Celsius citing record high global carbon dioxide (CO2) emissions
The Arctic has oil and gas reserves which Lloyd's of London
has estimated could draw investment of up to $100 billion within
a decade. Environmentalists warn Arctic drilling is too risky
and could have devastating consequences for the region.
(Editing by Jason Neely)