With a new coal-fired plant coming online about once a week, China is on course to overtake the United States as the world's leading carbon dioxide emitter this year or next, an official at the International Energy Agency said last week (see page 954).

This means, of course, that unless China and other major nations such as India and Brazil join a global effort to mitigate the effects of climate change, tough targets and sophisticated carbon markets across the developed world will eventually pale into insignificance. But the onus is still on the developed nations, who created the problem, to lead that effort.

China is now working on a national plan that will lay out the measures it intends to take to deal with climate change. Despite all the new power stations and the usual difficulty in discerning China's real intentions, there is one good reason to accept that its efforts are sincere: it is in China's self-interest to confront the problem. Assessments by both China and the Intergovernmental Panel on Climate Change have made clear that the nation is likely to be hit hard by climate change, which will increase pressure on water supplies and cut agricultural yields.

In the United States, momentum for domestic action on carbon emissions is growing. As it does so, the issue of how to ensure that China and other developing countries are on board — the issue that prevented the US Senate from ratifying the Kyoto Protocol in the first place — has resurfaced. Again, those who favour doing nothing are citing possible inaction in developing countries as an excuse for their own refusal to exercise leadership on the issue.

As before, attempts to force China and India into accepting caps on their carbon emissions by refusing to take action without them are doomed to fail. Developing countries have not played a significant role in raising levels of greenhouse gases in the atmosphere in the past, and their per-capita emissions remain far lower than those of the wealthier nations.

Practical considerations, as well as moral ones, preclude the rapid introduction of emissions caps and associated carbon-trading schemes in developing countries. Cap-and-trade schemes are only going to be effective in reasonably advanced economies, where accurate monitoring and reporting of emissions is feasible.

One starting point may be to push developing countries to sign up to more realistic goals than a blanket emissions cap, which as well as addressing the problem of climate change will also deliver associated benefits of high national priority. For example, building-efficiency standards can simultaneously tackle problems of energy security, materials shortages and air pollution in China. Bilateral agreements between rich and poor nations to share clean-energy technologies could help to ensure that these goals are met.

The Chinese government has taken some tentative steps towards managing its energy consumption. It has pledged, for example, to cut its energy intensity — the amount of energy used per unit of economic growth — by 20% between 2005 and 2010 (it isn't, so far, on course to meet this target). It has also put some fairly stringent vehicle-efficiency standards in place. Consistent pressure to step up efforts to meet such commitments could add up to significant reductions in emissions.

Carefully designed incentive mechanisms that encourage developing countries to engage in a global carbon market could also play a role. The Kyoto Protocol established the Clean Development Mechanism (CDM) in 2003. This allows industrialized nations to reduce the costs of complying with Kyoto, essentially by paying individuals in developing countries to adopt lower-polluting technologies than they otherwise would.

Currently, the CDM is rather limited in scope. However, as interest in a global carbon market grows, mechanisms of this type hold out some promise for delivering real global emissions reductions. The major developing nations are increasingly dependent on global economic integration and cannot afford to become outliers in any new global energy strategy that emerges.

In the short term, the best thing that wealthy countries can do to motivate action in the developing world is to take action themselves. Congress should note that a demonstration of good faith will be needed before the United States regains the credibility to engage seriously with countries such as China on this issue.