* Rapid emissions growth means cuts must be deep from 2020
* Talks lack ambition to deliver tough new targets -greens
Nov 28 (Reuters) - As the nations of the world struggle in
Doha to agree even modest targets to tackle global warming, the
cuts needed in rising greenhouse gas emissions grow ever deeper,
more costly and less likely to be achieved.
U.N. talks have delivered only small emissions curbs in 20
years, even as power stations, cars and factories pump out more
and more heat-trapping gases.
An overriding long-term goal set by all nations two years
ago to keep temperature rises to less than 2 degrees Celsius
(3.6 F) above levels prior to the Industrial Revolution is fast
slipping away.
"The possibility of keeping warming to below 2 degrees has
almost vanished," Pep Canadell, head of the Global Carbon
Project at Australia's Commonwealth Scientific and Research
Organization, told Reuters.
Disagreements mean the U.N. climate talks in Doha, Qatar,
that run until Dec. 7 have scant chance of making meaningful
progress. The talks are aimed at reaching a new deal to start by
2020 to slow climate change in the form of more floods,
droughts, rising sea levels and severe storms like Hurricane
Sandy that lashed the U.S. Northeast last month.
Global emissions of carbon dioxide (CO2), the main
greenhouse gas, have risen 50 percent since 1990 and the pace of
growth has picked up since 2000, Canadell said. In the past
decade, emissions have grown about 3 percent a year despite an
economic slowdown, up from 1 percent during the 1990s.
Based on current emissions growth and rapid industrial
expansion in developing nations, emissions are expected to keep
growing by about 3 percent a year over the next decade.
For the talks to have any chance of success in the long run,
emissions must quickly stop rising and then begin to fall.
Temperatures have already risen by 0.8 C (1.4 F) since
pre-industrial times.
"The alarm bells are going off all over the place. There's a
disconnect between the outside world and the lack of urgency in
these halls," Alden Meyer of the Union of Concerned Scientists
said at the Doha talks.
Nearly 1,200 coal-fired power plants, among the biggest
emitters, are proposed around the globe, with three-quarters of
them planned for China and India, a study by the
Washington-based World Resources Institute think-tank said last
week.
Emissions from China, the world's top carbon polluter, are
growing 8 to 9 percent a year and are now about 50 percent
higher than those of the United States. And China's carbon
emissions are not expected to peak until 2030.
POLLUTION
In some projections, global emissions will need to go into
reverse by mid-century, with the world sucking more carbon out
of the air than it puts in, if warming is to be kept to below 2
C.
And air pollution, mostly particles from fossil fuel use,
may be masking the warming by dimming sunshine.
"Those aerosols today hide about one-third of the effect of
greenhouse gases," Jean-Pascal van Ypersele, vice-chairman of
the U.N.'s Intergovernmental Panel on Climate Change (IPCC),
told Reuters.
Without that pollution, a breach of the 2 degree threshold
might already be inevitable, he said.
The latest IPCC report, in 2007, said keeping greenhouse gas
concentrations low would cost less than 3 percent of world gross
domestic product by 2030. So far, the panel has not assessed the
costs of delays, said Rajendra Pachauri, chairman of the panel.
The report also said that world emissions of greenhouse
gases would need to peak by 2015 to give a good chance of
keeping the average temperature rise to below 2 C.
But deep disagreement on future emissions cuts between rich
and poor nations has delayed the start of a new global pact
until 2020, undermining the chances of a robust extension in
Doha of the existing plan, the Kyoto Protocol, which obliges
almost 40 rich nations to cut emissions until the end of 2012.
The deadline for a deal on new cuts due to start in 2020 has
been put back to 2015, giving breathing space for the troubled
talks as ever more carbon enters the air.
Yet current emissions cut pledges are putting the planet on
course for a warming of 3 to 5 C, a U.N. report said last week,
adding that 2 C was still possible with tough action.
"The later we go in getting complete action and the higher
emissions are in 2020, the greater is the risk that these
targets are not possible or are extremely expensive," said Bill
Hare, head of the non-profit advisory organisation Climate
Analytics.
Key will be a switch to nuclear or biomass power and carbon
capture and storage. If these don't step up, there will be no
financially feasible solutions to meet the target, he said.
In Doha, both the United States and the European Union - the
main emitters among developed nations - say they will not deepen
their pledges for cuts by 2020. "It's a desperate situation,"
said Martin Kaiser of Greenpeace.
To be effective, the next climate pact from 2020 would need
global agreement for rapid and deep cuts. Under a scenario drawn
up by the IPCC, rich nations needed to achieve cuts of 25 to 40
percent by 2020 from 1990 levels.
But existing pledges are for less than 20 percent.
STARK MESSAGE
Canadell, citing work by the Global Carbon Project and other
researchers, said that to have a reasonable chance of keeping
warming to 2 C, global emissions would have to drop about 3
percent a year from 2020.
Since developed nations are meant to take the lead, that
would mean the rich would have to cut by between 4 and 5 percent
a year, he said. That could cripple economies by prematurely
shutting down coal-fired power plants and polluting factories.
Global accountancy firm PwC estimated that the improvement
in global carbon intensity - the amount of carbon emitted per
unit of economic output - needed to meet a 2 C target had risen
to 5.1 percent a year, from now to 2050.
"We have passed a critical threshold - not once since World
War Two has the world achieved that rate of decarbonisation, but
the task now confronting us is to achieve it for 39 consecutive
years," PwC said.