We're drawing to the close of what some scientists predict will be the warmest year on record. Yet the best that could be achieved at an international summit on global warming in Montreal last week was an agreement to continue non-binding talks.

Hot air isn't good enough. The longer the world waits to begin curbing emissions of greenhouse gases, the worse the situation will become. Even sharp cuts in greenhouse gas emissions may not be enough to forestall global disaster.

Voluntary emissions targets alone, such as those favored by President Bush, are unlikely to achieve the reductions necessary to counteract global warming and stabilize the planet's weather systems. Nor is it possible for developed countries — the worst offenders — to address this issue by itself. A study published this month by the federally funded National Center for Atmospheric Research showed the folly of this approach, which is the preference of fast-growing countries like China and India.

Researchers working for the center calculated that the growing trade imbalance between the United States and China resulted in a net increase in carbon-dioxide emissions between 1997 and 2003. Because Chinese industry relies more heavily on power generated by burning coal, and because it faces fewer emissions restrictions, the researchers found that the shift of manufacturing jobs increased the release of this key greenhouse gas by 700 million metric tons during that six-year period.

Neither the United States nor China are parties to the Kyoto Protocol, which limits emissions of greenhouse gases. But even countries that have signed that agreement are failing to meet its targets. Japan, Canada and 11 European Union countries have either increased their emissions or failed to reach their Kyoto targets.

Meanwhile, the costs of inaction are becoming alarmingly apparent. Earlier this year, scientists predicted that the number and severity of storms will increase along with ocean temperatures. Work by an MIT scientist that focused on Atlantic hurricanes was in the headlines this summer, but other researchers have documented similar effects in the Pacific and Indian oceans.

The United States, the world leader in technical innovation, should also be leading the way in combating global warming. Instead, the Bush administration has repeatedly balked at addressing the problem. Only last July did Bush grudgingly concede that global warming is real. At the Montreal summit American delegates very nearly scuttled the call for even non-binding talks.

The United States leads the world in greenhouse gas emissions. It must also lead the world into a new agreement that will reduce them, an agreement that takes into account the effects of international trade. A system of enforceable targets, coupled with expanded emissions trading, would seem to be the fairest approach.

As with all international agreements, the final product won't be perfect. But without U.S. leadership, it is unlikely to arrive before a global environmental crisis forces desperate measures.