The most exhaustive official account of global warming has just been published by the UN. John Maddox shares its anxieties but believes that the committees which produced it need reformby John Maddox / November 20, 1996 / Leave a comment
With the threat of an imminent nuclear exchange behind us, there is now only the prospect of global warming to keep us awake at nights. And that threat is not all that distant. By the middle of the next century, we shall all be uncomfortably warmer than now unless we live in Manitoba or Siberia-by which time it will be too late to do much about a further worsening of the climate.
That is what the intergovernmental panel on climate change (IPCC) has been saying since 1990, when it produced its first assessment of the prospects. (Others, Roger Revelle of Harvard University in particular, began the refrain more than four decades earlier.) The success of the UN framework convention on climate change negotiated at Rio in 1992 suggests that governments in general believed what the IPCC had said, although the Bush administration in the US was more than hesitant.
The IPCC is now in the throes of producing its second assessment, the most important part of which has just appeared (Climate Change 1995, CUP 1996). The earlier version, timed to precede the Earth summit at Rio, was widely lampooned on several grounds, not least because the second and third parts of the exercise were inconsistent with each other and were manifestly na?ve as well. This time round, part one has drawn the flak, perhaps because the other two have yet to appear.
Part one? Parts two and three? What is this? You need to know that the IPCC is a creature of two UN agencies, the World Meteorological Organisation (WMO) and the UN Environmental Program (Unep) and that it was founded in anticipation of the Rio summit to make an assessment of global warming. The concept was grandiose and old- fashioned.
There were to be three working groups (WG1, WG2 and WG3), working simultaneously; the first would deal with the science, the second with the economic and social aspects and the third would make recommendations to governments. The trouble with the first assessment was that nobody had considered how WG3 could make intelligent recommendations without seeing the reports of WG1 and WG2 and how WG2 could say what the socio-economic consequences of global warming would be without seeing WG1’s conclusions.
But it is all in a good cause. If it is relevant, my own belief is that the middle ground projections of global warming, if proved correct, will be…