Nations can benefit from cutting greenhouse-gas emissions, but there are significant uncertainties about how much it will cost in the long run to stabilize the levels of such gases, according to a report issued today by the Intergovernmental Panel on Climate Change. The report follows other recent studies by the panel, on the human causes of global warming and the likely effects of such climate change.

The report released today looks at the issue of mitigating climate change by summarizing studies published over the past several years. It says that emissions of greenhouse gases increased 70 percent from 1970 to 2004. Emissions of carbon dioxide, the biggest component of greenhouse-gas emissions, are expected to go up 45 percent to 110 percent from 2000 to 2030 if no steps are taken. It would cost nations 0.2 percent to 2.5 percent of the world’s gross domestic product to stabilize levels of greenhouse gases at close to twice the amount they were in preindustrial times. By curbing such gases, however, nations will also benefit from reduced air pollution, which may offset substantial fractions of the cost of mitigation, the report says. —Richard Monastersky