ONE of the toughest long-term challenges humanity faces is possibly dramatic climate change due to global warming. It's too serious a matter for government bureaucrats to distort the conclusions of scientists who study the threat. Yet that is exactly what the Office of Management and Budget (OMB) did in censoring testimony to be given by James E. Hansen last week before the United States Senate Subcommittee on Science, Technology, and Space.
It's true that Dr. Hansen was prepared to give more certainty to computer projections of climatic change than the state of scientific knowledge warrants. But in seeking to give his testimony a more ``realistic'' perspective, OMB puts words into Hansen's mouth that Hansen himself does not believe. This was an offensive - and silly - act that only served to further distort the debate and to focus public attention on the wrong issue.
There are plenty of experts who can point up the weaknesses in Hansen's conclusions. The overriding question is what actions should be initiated now in spite of the scientific uncertainties. If we wait until the ``iffy'' science is no longer ``iffy,'' it will be too late to avert possible climate disasters.
Hansen, who is director of NASA's Goddard Institute for Space Studies, has a reputation for being a bit alarmist. He drew criticism last year when he asserted that a series of unusually warm years in this decade is probably the first sign of global warming due to the action of heat-trapping gases released by human activity. He made that claim more strongly before general audiences and Congress than when he talked to scientific colleagues, who pointed out that a few hot summers don't make a climatic trend.
Hansen's original testimony last week would have stressed that computer models of the climate system predict drastic changes as the warming effect of carbon dioxide (released by burning fossil fuels), methane, and other heat-trapping gases takes effect.
These include such changes as intensified drought in some North American grain-growing areas, more intense hurricanes, and shifts in regional precipitation patterns.
Hansen's position is that these projections are good enough to spur action now. In fact, they still are quite uncertain. The computer models, for example, still can't take adequate account of changes in cloudiness, which might have a cooling effect.
So what? Many of the indicated actions would be worth taking anyway. Will fertile farmlands dry out? Then develop drought-tolerant crops. They would be useful in many parts of the world, whatever happens. Will water supplies change? Then work out more efficient water management. We will need that even if there is no climate change.
Likewise, energy conservation will slow the carbon dioxide buildup. But we need to conserve energy anyway, especially as developing nations modernize their economies and boost their energy use.
Humanity needs to reorganize the world economy to make more efficient use of its resources in any event. But this will also help us adapt to the kind of climate changes Hansen envisions.
Sir Crispin Tickell, Britain's United Nations representative, has called for a global conference to consider joint action toward this end. It could base its work on the report, late next year, of the International Panel of Climate Change. The panel - chaired by Britain, the Soviet Union, and the United States - is conducting a three-year study of all aspects of a possible global warming.
The Bush administration should give its attention to this larger issue and stop playing games with scientists, even if they do work for the government and are a bit extreme in their conclusions.