Alister Doyle, Reuters 13 Aug 09;
BONN, Germany (Reuters) - A goal of limiting global warming to 2 degrees Celsius (3.6 Fahrenheit) could mean crippling costs with gasoline taxes rising to $35 a gallon by 2100, a self-styled "skeptical environmentalist" said on Friday.
"The two degrees limit would simply cost too much," Danish statistician Bjorn Lomborg told Reuters, adding meeting the goal could total 12.9 percent of world gross domestic product (GDP) by 2100.
Major economies including top emitters China and the United States last month backed a target of limiting global warming to a 2 degree Celsius rise over pre-industrial levels to avoid the worst effects of climate change including floods, droughts and rising seas.
Most governments say costs will be easily manageable.
Lomborg, author of "The Skeptical Environmentalist," said gradual cuts in carbon dioxide, rather than drastic reductions, were a better solution for a U.N. climate treaty due to be agreed in December in Copenhagen.
"We should cut some carbon, but big cuts right now are a poor decision," Lomborg, who is head of the Copenhagen Consensus Center, told Reuters by telephone. About 180 nations are meeting in Bonn this week for talks on the new treaty.
The level of taxes implied by an ill-guided all-out assault to limit global warming to 2 Celsius would mean gasoline taxes of $0.90 a gallon, rising to $35.5 by 2100, he said.
IRREVERSIBLE CONSEQUENCES
Lomborg's views contrast with the U.N.'s Intergovernmental Panel on Climate Change (IPCC), whose scenarios indicate that emissions should peak quickly and then be reduced fast to avoid the worst of global warming.
Many climate experts say delay could worsen problems, perhaps with irreversible consequences such as disappearance of many Himalayan glaciers that provide meltwater in dry seasons for millions of people, extinctions of species of animals and plants or a runaway thaw of West Antarctica, raising sea levels.
Richard Tol, a professor at the Economic and Social Research Institute in Ireland and an IPCC author who summarized recent research findings for Lomborg, said past computer models had in some cases been misleading.
"A well-designed, gradual policy of carbon cuts could substantially reduce emissions at low cost to society," he said. "Ill-designed policies, or policies that seek to do too much too soon, can be orders of magnitude more expensive."
The IPCC said in 2007 that a 2 Celsius target would brake world GDP by less than 5.5 percent by 2050. But Tol said costs could rise by 2100, based on longer-term projections overseen by the Stanford Energy Modeling Forum (EMF) in the United States.
"The 12.9 percent is for those models that could meet these targets. About half of the models found that these targets are impossible to reach within the constraints of their model," he told Reuters of the EMF findings.
"In my model, for instance, we could meet the (2 Celsius) target if we cut the world population by a third; in another model, we could meet the target if we multiply the number of nuclear reactors by a factor of five between now and 2020."
Lomborg said a moderate tax of $7 per tonne of carbon dioxide emissions, rising with inflation over the century, would be the best deal and avoid $1.51 of climate damage per dollar spent.
(Editing by Janet Lawrence)
