Key scientist concerned that talks are missing the mark

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

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 U.N. conference, richer nations are offering firm reductions in emissions of carbon dioxide and other greenhouse gases ranging from 3 to 4 percent for the United States to 20 percent for the European Union, in terms of 2020 emissions compared with 1990.

One authoritative independent analysis finds the aggregate cuts amount to 8 to 12 percent. But the Intergovernmental Panel on Climate Changes (IPCC), the U.N.-sponsored science network, recommends that reductions average in the 25- to 40-percent range to head off the worst of global warming.

The IPCC's Thomas Stocker told reporters the IPCC targets "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.