Mankind to Blame for Warming but Can Slow Damage - UN
Date: 30-Aug-07
Country: AUSTRIA
Author: Alister Doyle, Environment Correspondent
Underlining the need for speed, it says a European Union
goal of holding temperature rises to a maximum 2 Celsius (3.6
Fahrenheit) above pre-industrial times is almost out of reach.
The 21-page study, due for release in November, lays out
possible responses to global warming but cautions that some
impacts are already inevitable, such as a gradual rise in sea
levels that is set to last for centuries.
The report gives a first overview of 3,000 pages of research
by the UN's climate panel already published in three
instalments this year about the science, the likely impacts and
the costs of slowing climate change.
The authoritative summary, obtained by Reuters and meant to
guide governments in working out how to slow warming, reiterates
that humans are to blame for climate change but that clean
technologies are available to offset the most harmful emissions.
"Most of the observed increase in globally averaged
temperatures since the mid-20th century is very likely due to
the observed increase in anthropogenic (from human activities)
greenhouse gas concentrations," it says.
"Very likely" means at least 90 percent probability, up from
66 percent in a previous report by the UN's Intergovernmental
Panel on Climate Change (IPCC) in 2001 when the link was only
judged "likely". The IPCC draws on work by 2,500 scientists.
The report shows a table indicating worsening damage such as
bleached corals, coastal flooding, increasing costs of treating
disease, deaths from heatwaves and rising risks of extinctions
of species of animals and plants.
But it says: "Many impacts can be avoided, reduced or
delayed" by cutting greenhouse gas emissions.
FOSSIL FUELS
Among options to offset warming, blamed mainly on greenhouse
gases from burning fossil fuels, are energy efficiency, wider
use of renewable energies, carbon markets or burying carbon
dioxide from coal-fired power plants.
The report indicates that the cost of such initiatives would
be manageable for the world economy.
Global gross domestic product (GDP) in 2030 would be reduced
by up to 3 percent in the most stringent case that would require
emissions to peak within about 15 years. Other less tough goals
would mean only a fractional loss of GDP by 2030.
The report will be issued in Valencia, Spain, on Nov. 17
after review by governments, along with an even shorter 5-page
summary. The draft is dated May 15 -- an updated version has
been written this month to take account of government
suggestions, scientists said.
"Warming of the climate is now unequivocal, as is now
evident from observations of increases in global average air and
ocean temperatures, widespread melting of snow and ice and
rising global mean sea level," the summary begins.
The report reiterates best estimates that temperatures will
rise by 1.8 to 4.0 Celsius (3 to 7 Fahrenheit) this century and
that sea levels will rise by between 18 and 59 centimetres.
But it says ocean levels are likely to keep rising "for many
centuries" even if greenhouse gases are stabilised, because
water expands as it heats up. The deep oceans will keep heating
up as warmth filters down from the surface.
Under a range of scenarios, such thermal expansion of the
oceans alone would bring sea level rises of 0.4 to 3.7 metres in
coming centuries, without counting any melting of ice in
glaciers or in the vast Greenland or Antarctic ice sheets.
About 1,000 delegates from 158 nations are meeting in Vienna
this week to discuss ways to extend the UN's Kyoto Protocol
for fighting warming beyond 2012 and to widen it to include
outsiders such as the United States and developing nations.
