U.N.: Climate Change 'Irreversible'

Nov. 16, 2007 -- Less than three weeks before a crucial conference on climate change, U.N. experts agreed Friday on a draft report that warns global warming may have far-reaching and irreversible consequences.

The report by the Intergovernmental Panel on Climate Change (IPCC) is designed to guide policymakers for the next five years.

Delegates to the Nobel-winning scientific authority agreed the draft after night-long negotiations, chief French delegate Marc Gillet said.

Human activities "could lead to abrupt or irreversible climate changes and impacts," the agreed text said.

The report will be officially adopted on Saturday, followed by a press conference attended by United Nations chief Ban Ki-moon.

It summarizes three massive documents issued this year covering the evidence for climate change; the present and possible future impacts of it; and the options for tackling the peril.

After Saturday, attention shifts to a key meeting in Bali, Indonesia, where governments must set down a "roadmap" for negotiations culminating in a deal to slash carbon emissions and help developing nations cope with climate change.

The IPCC experts agreed that the rise in Earth's temperature observed in the past few decades was principally due to human causes, not natural ones, as "climate skeptics" often aver.

The impacts of climate change are already visible, in the form of retreating glaciers and snow loss in alpine regions, thinning Arctic summer sea ice and thawing permafrost, according to the three IPCC reports issued earlier this year.

But sometimes sharp disagreement emerged during the five days of negotiations in Valencia to hammer out the summary, even though the main findings remained untouched.

U.S. delegates in particular said references to "irreversible" climate change and impacts were imprecise.