HOW much more carbon dioxide can the atmosphere absorb before it triggers catastrophic climate change? That is the key question that climatologists working with the Intergovernmental Panel on Climate Change (IPCC) will be addressing in the coming months.
In Berlin this week, the US and a few other industrialised countries are defending their reluctance to commit themselves to future reductions in their emissions of greenhouse gases on the grounds that the scientists cannot yet offer an answer.
Legally, under the terms of the Climate Change Convention, they have a case. The signatories to the convention have agreed to stabilise greenhouse gases at concentrations "that would avoid dangerous anthropogenic interference with the climate system". The problem, the IPCC says, is that "it is not yet possible to define what such an objective means in quantitative terms".
Instead, IPCC chairman Bert Bolin told the meeting of signatories in Berlin that in its ...
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