Reuters AlertNet - ANALYSIS-Scientists examine causes for lull in warming
Climate scientists must do more to work out how exceptionally cold winters or a dip in world temperatures fit their theories of global warming, if they are to persuade an increasingly sceptical public.
At stake is public belief that greenhouse gas emissions are warming the planet, and political momentum to act as governments struggle to agree a climate treaty which could direct trillions of dollars into renewable energy, away from fossil fuels.
Public conviction of global warming's risks may have been undermined by an error in a U.N. panel report exaggerating the pace of melt of Himalayan glaciers and by the disclosure of hacked emails revealing scientists sniping at sceptics, who leapt on these as evidence of data fixing.
Scientists said they must explain better how a freezing winter this year in parts of the northern hemisphere and a break in a rising trend in global temperatures since 1998 can happen when heat-trapping gases are pouring into the atmosphere.
"There is a lack of consensus," said Kevin Trenberth, head of the Climate Analysis Section at the U.S. National Center for Atmospheric Research, on why global temperatures have not matched a peak set in 1998, or in 2005 according to one U.S. analysis.