Scientist: Climate talks aim too low for target

The cuts in greenhouse gases offered at the 192-nation climate conference are "clearly not enough" to assure the world it will head off dangerous global warming, a key UN-affiliated scientist said Saturday.

13/12/2009 - Such projections, moreover, don't even account for the "potentially hugely important" threat of methane from the Arctic's thawing permafrost, other researchers said.

Midway through the two-week UN conference, richer nations are offering firm reductions in emissions of carbon dioxide and other greenhouse gases ranging from 3-4 percent for the US to 20 percent for the European Union, in terms of 2020 emission levels compared with 1990.

One authoritative independent analysis finds the aggregate cuts amount to 8-12 percent. But the Intergovernmental Panel on Climate Changes (IPCC), the UN-sponsored science network, recommends that reductions average in the 25-40-percent range to keep global temperature increases below 2 degrees C (3.6 F) above preindustrial levels and head off the worst of global warming.

"I think it is clearly not enough," the IPCC's Thomas Stocker said of the numbers discussed here. "We are by far short of having security that the 2-degree target will be met."

The Swiss physicist heads the IPCC's Working Group I, the climate science group that, among other things, assesses the impact that emissions — from fossil-fuel burning, deforestation and other sources — have on concentrations of global-warming gases in the atmosphere and then on temperatures.

Stocker told reporters the IPCC-recommended target "may be too much to ask at this stage" — too politically daunting to achieve in the current annual conference. But he suggested climate talks should aim at longer-term commitments, over decades, not the short commitment periods envisioned in the annual conferences.

Even limiting the temperature rise to 2 degrees C would not forestall serious damage, the IPCC chairman, Rajendra Pachauri, told reporters. "We would get sea-level rise, through thermal expansion alone, of 0.4 to 1.4 meters" (1.3 feet to 4.5 feet), he said.

Climate science co-chair Stocker acknowledged that IPCC projections do not include the potential "tipping point" addition of trapped methane, a powerful greenhouse gas that would be released as permafrost thaws in the far north.

Do UNFCCC