Global warming is mostly about arcane weather science that may - or may not - affect your grandchildren's grandchildren. Experts in lab coats do things like study minuscule bits of carbon dioxide trapped in prehistoric ice bubbles, then estimate how many degrees warmer this could make it a century from now.
So why all the fuss among governments and special interests as more than 150 nations prepare to meet in Kyoto, Japan, next week?
It's not so much the science of climate change that will be debated there - most scientists agree that human activities are heating things up and that this could have serious environmental consequences. Rather, the debate is over the steps that should be taken to mitigate global warming. And, more to the point, what that will cost and who should pay.
It's set off a vigorous debate among governments around the world about who bears responsibility for climate change and how drastic the steps to address it should be.
Going into Kyoto, the United States is at the center of the debate. Many nations - especially those in Europe - consider the United States arrogant and are pushing for the US to pick up the biggest share of the tab.
Critics note that the United States (with just 4 percent of the world's population) emits nearly a quarter of all "greenhouse gases." Britain's Prime Minister Tony Blair said at a special United Nations meeting last summer that "the biggest responsibility falls on those countries with the biggest emissions."
US government figures released earlier this month confirm that despite all the energy conservation and efficiency measures adopted in recent years, Americans are using more energy and emitting more greenhouse gases. This is largely because the economy has been booming and the population growth rate here is higher than in most other developed countries.
The US position on cutting emissions, as articulated last month by President Clinton, does not match the European Union's goal. The 15-nation EU wants to reduce greenhouse-gas emissions (mainly carbon dioxide) to 1990 levels by the year 2000 - in accordance with the goal set five years ago at the Earth Summit in Brazil.
Instead, Clinton would phase in greenhouse-gas reductions to 1990 levels, pushing the deadline back as far as 2012. But by this date, Japan says the world should already have cut emission levels 5 percent below 1990 levels, while Europeans want to see them cut by 15 percent.
Clinton's proposal also assumes that the US would have to cut carbon levels 28 percent (about 375 million tons a year) to reach his goal. But the new data show that even steeper cuts - 34 percent - would be necessary.
"That's like adding five more miles to a 26-mile marathon race," says Raymond Kopp, a researcher at the nonpartisan research organization Resources for the Future.
Defenders of the US position point out that America produces many energy-intensive things the rest of the world values (agricultural goods and minerals, for example). The vastness of the country requires more fuel-burning transportation, they add. This is the same position taken by Canada and Australia, the two developed countries allied with the US in wanting to move more deliberately to reduce global warming.
"Canadian homes and businesses must be heated or cooled against temperature extremes experienced by few other nations. And goods must be shipped over very long distances and some very tough terrain - just ask any grain farmer about those challenges," says Ralph Goodale, Canada's minister of natural resources. "At the same time, with an expanding economy and one of the highest rates of population growth in the industrialized world, the demand for energy in Canada continues to increase, despite considerable improvements in energy efficiency."
A head start
It's also noted that two key European countries in effect had a head start in reducing carbon emissions early in this decade (and therefore just after the baseline year of 1990).
Under Prime Minister Margaret Thatcher, Britain shut down old coal mines and began switching to natural gas (which produces less carbon dioxide in burning). And following the fall of the Berlin Wall and German reunification, much of the high-polluting state industries in the former East Germany collapsed.
"In both cases, this is due to national circumstances, quite unrelated to greenhouse-gas emissions," says Paul O'Sullivan, deputy chief of Mission at the Australian Embassy in Washington.
France, meanwhile, generates 80 percent of its electrical power with nuclear plants - which do not emit carbon dioxide but have their own potential environmental problems, such as radioactive waste.
Because of these differences, the US and some other countries will push for "differentiation" at Kyoto. This means that a country's economic situation and rate of population growth would be taken into account in figuring "targets and timetables" for carbon reduction.
Australia, for example, expects to lower its per capita carbon emissions significantly by 2010. But because its population is projected to grow 30 percent between 1990 and 2020 (compared with less than 3 percent in more-densely-packed Europe), overall emissions will continue to rise.
"We do not see why an Australian should have to shoulder more of the economic burden for emission abatement than a European," says Mr. O'Sullivan. "The economic costs to each should be the same."
In any case, public attitudes about the pace and amount of government action to stem global warming differ markedly between the US and many other countries.
A recent survey of 27,000 people in 24 countries by Environics International, a Toronto-based research firm, shows that Americans are much more likely than people in other countries to feel that "we should not take major action to reduce human impacts on climate until we know more, because of the great economic costs involved." (See chart.)
This doesn't mean that Americans would not be willing to help out in reducing global warming. In fact, nearly three-quarters of those polled say they'd pay 5 cents more for a gallon of gasoline, if that's what it took. Sixty percent would pay as much as a quarter more per gallon, according to a recent poll by the Pew Research Center for the People and the Press.
But economists note that there would be more to a fuel tax than just higher prices at the pump. Heating costs would rise, as would the price of goods shipped by road, rail, or air. Indeed, figuring the economic costs of fighting global warming can be a dizzying process, involving countless variables.
"Any serious attempt to cut emissions will have clear and immediate costs, but the benefits may not appear for a long time," says J.W. Anderson of Resources for the Future. "To the extent that the benefits may be disasters that didn't happen [a flood, for example], they may never be obvious - but the costs will be."
This uncertainty, however, has not kept economists - some independent, some on behalf of special interests - from weighing in on both sides.
Clinton's carbon-reduction proposal could amount to "the single most expensive environmental-protection measure ever adopted by the US government," warns the American Automobile Manufacturers Association in a recent study compiled by Charles River Associates.
Unless major developing countries such as India and China "participate fully" in reducing carbon emissions, the automakers assert, the results would include: a loss in US gross domestic product of some $90 billion in 2010 and $350 billion by 2030; a drop in household incomes of $1,250 per year in 2010 and $4,250 in 2030; and job losses amounting to 7 percent of the labor force in the motor-vehicle industry and two-thirds of the labor force in the coal industry.
Yet this is far from a universally accepted prognostication.
"There has been a great deal of disinformation on this subject, claims of millions of jobs being lost and the American standard of living being reduced," says Stephen DeCanio, an economist at the University of California at Santa Barbara and senior staff economist with the President's Council of Economic Advisers during the Reagan administration. "Those claims don't hold up when examined objectively."
More than 2,500 American economists (including eight Nobel laureates) signed a statement asserting that "there are many potential policies to reduce greenhouse-gas emissions for which the total benefits outweigh the total costs."
"For the United States in particular, sound economic analysis shows that there are policy options that would slow climate change without harming American living standards, and these measures may in fact improve US productivity in the longer run," says this statement.
In the end, the diplomats at Kyoto must weigh what's known at present - both scientifically and economically - with a climate-change forecast that remains murky.