* Most greens oppose nuclear due to safety, costs
* Many experts say all technologies needed in climate fight
* U.N. talks in Warsaw working on global climate deal
By Nina Chestney and Alister Doyle
WARSAW, Nov 19 The lack of progress at United
Nations talks to agree a deal to tackle global warming is
calling into question the insistence of many environmental
groups that low-carbon nuclear power can never be the answer.
Japan dismayed many at the 195-nation conference last week
by saying it would fail to reach its greenhouse gas emissions
targets for 2020 after the 2011 Fukushima disaster because it is
replacing nuclear power with the fossil fuels gas and oil.
In Europe, more coal is being burnt due to cheap U.S.
exports displaced by the U.S. shale gas boom. The continent's
biggest economy, Germany, is also phasing out its nuclear plants
Most environmental groups advocate scaling up renewable
energy such as wind and solar power but do not support nuclear
due to safety issues, cost, and the time it takes to build.
But some experts say their stance is too narrow, making it
harder to agree an effective deal in 2015 to cut greenhouse
gases and keep temperature rises within safe limits of 2 degrees
Celsius (3.6 Fahrenheit).
"If you are thinking seriously about holding climate change
to no more than 2 degrees you can't afford to rule out any of
the low-carbon technologies," said Nicholas Stern, chair of the
Grantham Institute on Climate Change and the Environment at the
London School of Economics.
"You need to be investing in all of them - including
nuclear," he told Reuters.
Robert Stavins, director of the Harvard Environmental
Economics Program, said economists wanted all technologies to be
considered, whether it was carbon capture and storage, nuclear
power or geoengineering.
"It may turn out to be necessary, so you need to know the
possible benefits, costs and risks," he said.
'NO TO NUCLEAR'
Despite the setback in Japan, many environmental groups are
adamant that both high-emissions coal, the main target of their
ire in Warsaw, and nuclear can be phased out.
"Nuclear power = dirty power" and "Don't nuke the climate"
were among signs held by protesters outside the U.N. meeting on
After shuttering its nuclear industry, Japan said it was
easing its emissions goal for 2020 to a maximum 3 percent rise
above 1990 levels from a previously planned cut of 25 percent.
That is because fossil fuels will take over.
"We need to have everything on the table. We shouldn't be
ruling things out," said Nathaniel Keohane, vice-president for
international climate at the Environmental Defense Fund, which
is among the few green groups not totally opposed to nuclear.
Alden Meyer, representing the Union of Concerned Scientists
think tank, said his group was neither pro- nor anti-nuclear.
"I am not getting the sense that many (green) organisations
are relaxing their stance on nuclear. If anything, Fukushima has
hardened the opposition to nuclear," he said.
Earlier this month, four leading climate experts, including
former NASA scientist James Hansen, sent an open letter to green
groups urging them to rethink.
"We appreciate your organizations' concern about global
warming, and your advocacy of renewable energy. But continued
opposition to nuclear power threatens humanity's ability to
avoid dangerous climate change," they wrote.
Worldwide, 435 nuclear reactors generate about 13.5 percent
of the world's electricity, according to the World Nuclear
Association's website. It said more than 70 reactors were under
construction around the world.
Last month, Britain signed a deal with French utility EDF
to build a 16 billion pound ($26 billion) nuclear
plant, the first new one agreed in Europe since Fukushima.
A report by a U.N. panel of climate scientists in 2011
said renewables could make up between 15 and 77 percent of world
energy by 2050, depending on the scenario.
So renewables are still the main focus for greens.
"Our concern is that we need to get away from the obsession
with nuclear and focus on renewables," WWF-UK chief executive
David Nussbaum said. "All the ingenuity, technology and
private-sector focus needs to be put into renewables."
($1 = 0.6206 British pounds)
(Editing by Dale Hudson)