Study: Temperatures Could Rise 7-degrees F by 2060
Worst case study: global temp up 7.2F degrees by 2060s
Reuters, Nov. 29, 2010
CANCUN,
Mexico (Reuters) – World temperatures could soar by 4 degrees Celsius
(7.2 degrees Fahrenheit) by the 2060s in the worst case of global
climate change and require an annual investment of $270 billion just to
contain rising sea levels, studies suggested.
Such
a rapid rise, within the lifetimes of many young people today, is
double the 2 degrees C (3.6 degrees Fahrenheit) ceiling set by 140
governments at a U.N. climate summit in Copenhagen last year and would
disrupt food and water supplies in many parts of the globe.
Rising
greenhouse gas emissions this decade meant the 2 degree goal was
"extremely difficult, arguably impossible, raising the likelihood of
global temperature rises of 3 or 4 degrees C within this century," an
international team wrote.
The
studies, published to coincide with annual U.N. climate talks in Mexico
starting on Monday, said few researchers had examined in detail the
possible impact of a 4 degrees C rise above pre-industrial levels.
"Across
many sectors -- coastal cities, farming, water stress, ecosystems or
migration, the impacts will be greater," than at 2 degrees, wrote Mark
New of Oxford University in England, who led the international team.
One
study, published in the British journal Philosophical Transactions of
the Royal Society A, said temperatures could rise by 4 degrees C in the
worst case by the early 2060s.
Other
scenarios showed the threshold breached later in the century or not at
all by 2100, raising risks of abrupt changes such as a loss of Arctic
sea ice in summer, a thaw in permafrost or a drying out of the Amazon rainforest.
MIGRATION
One
of the papers gave what it called a "pragmatic estimate" that sea
levels might rise by between 0.5 and 2 meters (1.64 to 6.56 feet) by
2100 if temperatures rose 4 degrees Celsius.
Containing
a sea level rise of 2 meters, mostly building Dutch-style sea walls,
would require annual investments of up to $270 billion a year by 2100.
That
sum might limit migration to perhaps 305,000 people from the most
vulnerable areas, wrote Robert Nicholls of the University of
Southampton. Lack of protective measures could mean the forced
resettlement of 187 million people.
People living on small islands, in Asia, Africa or river deltas were most at risk.
The
studies concluded that governments should do more both to cut
greenhouse gas emissions and research back-up methods such as
"geo-engineering" programs that could dim sunlight or seek to suck
greenhouse gases from the air.
|
