DOHA, Qatar (AP) -- Though it's tricky to link a single weather event to climate change, Hurricane Sandy was "probably not a coincidence" but an example of the extreme weather events that are likely to strike the U.S. more often as the world gets warmer, the U.N. climate panel's No. 2 scientist said Tuesday.
Jean-Pascal van Ypersele, the vice chairman of the Intergovernmental Panel on Climate Change, predicted that as stronger and more frequent heat waves and storms become part of life, people will stop asking whether global warming played a role.
"The new question should probably progressively become: Is it possible that climate warming has not influenced this particular event?" he told The Associated Press in an interview on the sidelines of U.N. climate negotiations in Qatar.
Ypersele's remarks come as global warming has re-emerged as an issue in Washington following the devastating superstorm — a rarity for the U.S. Northeast — and an election that led to Democratic gains.
After years of disagreement, climate scientists and hurricane experts have concluded that as the climate warms, there will be fewer total hurricanes. But those storms that do develop will be stronger and wetter.
It is not correct to say Sandy was caused by global warming, but "the damage caused by Sandy was worse because of sea level rise," said Princeton University climate scientist Michael Oppenheimer. He said the sea level in New York City is a foot higher than a century ago because of man-made climate change.
On the second day of a two-week conference in the Qatari capital of Doha, the talks fell back to the bickering between rich and poor countries that has marked the negotiations since they started two decades ago. At the heart of the discord is how to divide the burden of cutting emissions of heat-trapping gases, including carbon dioxide.
Such emissions, primarily from the burning of fossil fuels such as coal and oil, have increased by 20 percent since 2000, according to a U.N. report released last week.
Van Ypersele (vahn EE-purr-say-luh) said the slow pace of the talks was "frustrating" and that negotiators seem more concerned with protecting national interests than studying the science that prompted the negotiations.
"I would say please read our reports a little more. And maybe that would help to give a sense of urgency that is lacking," he said.
Marlene Moses, the head of a coalition of island nations that view the rising sea levels as an existential threat, said that was good advice.
"These are the kind of people that it is probably a good idea to listen to," she said. "It is very much in the interest of small islands to focus on the science, which is why we have always based our positions on the latest research and why here we are calling for dramatically higher ambition."
Since 1990, the Intergovernmental Panel on Climate Change, or IPCC, has released four reports with projections on how global warming will melt glaciers and ice caps, raise sea levels and shift rainfall patterns with impacts on floods and droughts. The panel shared the 2007 Nobel Peace Prize with climate campaigner Al Gore, the former U.S. vice president.
The IPCC is set to start releasing portions of its fifth report next year. Van Ypersele would not discuss the contents except to say the report will include new research on the melting of ice sheets in Greenland and Antarctica, boosting previous estimates on sea level rise.
He said the scientific backing for man-made climate change is now so strong that it can be compared to the consensus behind the principles of gravity.
"It's a very, very broad consensus. There are a few individuals who don't believe it, but we are talking about science and not beliefs," Van Ypersele told AP.
Climate change skeptics say IPCC scientists have in the past overestimated the effect of the accumulation of CO2 in the atmosphere and underplayed natural cycles of warming and cooling. Others have claimed the authors, who aren't paid for their work, exaggerated the effects that climate change will have on the environment and on human life.
Negotiators in Doha are supposed to start talks on an elusive global treaty to rein in emissions. They have set a deadline of 2015 to adopt that pact, which would take effect in 2020.
Among other topics, they are discussing how to help poor countries convert to cleaner energy sources and adapt to a shifting climate, as well as extending the expiring Kyoto Protocol, an agreement that limits the greenhouse emissions of industrialized countries.
The U.S. rejected the Kyoto deal because it didn't cover world-leading carbon polluter China and other fast-growing developing countries. Other rich countries including Canada and Japan don't want to be part of the extension, which means it will cover less than 15 percent of global emissions.
"Japan will not be participating in a second commitment period, because what is important is for the world is to formulate a new framework which is fair and effective and which all parties will join," Japanese delegate Masahiko Horie said.
Meanwhile, a series of recent climate reports have underscored the depth of the challenge before the U.N. climate negotiators. A report released Tuesday by the U.N. Environment Program warned current climate projections are likely too conservative because they don't factor in the thawing of permafrost — a layer of soil that stays frozen year-round in cold climates.
Lead author Kevin Schaefer, of the National Snow and Ice Data Center in Colorado, said 1,700 gigatons of carbon are locked up in permafrost primarily in the U.S., China, Russia and Canada. He called for further studies on the potential climate impact if it's released, saying up to 39 percent of total emissions could come from permafrost by 2100.
AP Environment Writer Michael Casey contributed to this report.
Karl Ritter can be reached at www.twitter.com/karl_ritter