Is the United States ready to cut its carbon emissions, as the rest of the world demands? Not a chance. Are the poor countries ready to promise to cap their own emissions, as the US Senate is demanding? No way. Is the Kyoto meeting therefore heading for abject failure? Not necessarily.

The differences between the two sides could be accommodated. And experts agree that the essence of any such accommodation will be the practices known as ‘joint implementation’ and emissions trading.

‘Joint implementation’ is the term used by economists to describe projects carried out by the rich countries in poor countries in order to help meet the former's targets for reducing greenhouse gas emissions.

Instead of slapping five cents on the price of a gallon of gasoline, for example, the United States could attempt to meet its own reduction targets by helping to construct a hydro-electric scheme in Guatemala, alleviating the need for that country to generate electricity by burning fossil fuel.

Under the related concept of emissions trading, governments — or even corporations — could buy and sell emissions credits. If Japan could not meet its own emissions goal, for example, it would be able to buy ‘credits’ from a nation such as Russia that was on course to meet its target.

Economists believe that such a market would redistribute emission cuts to wherever costs are lowest. Indeed, trading in emissions of sulphur dioxide has been tried out between corporations in the United States, and has been highly successful in reducing the costs of cutting pollution.

But vast obstacles remain to the use of either joint implementation or emissions trading in a global scheme to cut greenhouse gas emissions. In the case of joint implementation, a programme of pilot schemes introduced as part of the 1995 Berlin mandate has so far achieved little.

Europe and the poor countries want the pilot programme to continue for a couple of years on its current basis. But the United States believes that the scheme has been slow to take off because it does not give participants any ‘credits’ against their own emissions targets — and wants it reformed to do precisely that.

Joint implementation need not only give credits to the rich, donor country, but could do so to the poor, recipient nation as well. But many poor countries don't want that, as it would imply their acceptance of the need for caps on their own emissions. “They see joint implementation as the start of a slippery slope” towards accepting caps, says one diplomat.

According to Bob Dickson, head of the US government's joint implementation office, “We'd like to end the pilot phase and get an agreement for joint implementation with crediting to all parties.” But after two years of trying, the United States has only won the support of Costa Rica, and possibly Argentina, for its vision of joint implementation.

Emissions trading is, if anything, even more fraught. A trading regime would probably be limited at first to those rich countries — the United States, western Europe and Japan — that have the legal and technical equipment to monitor emissions and implement a trading scheme.

Trading could occur at two levels: between nations, and between corporations within each nation. The latter would be relatively straightforward in countries with competitive, private-sector energy markets, such as the United States.

But any global scheme would be far more complex, as it would require global policing. Commentators such as Ed Parson, a specialist in emissions trading at Harvard University's John F. Kennedy School of Government, point out that sulphur dioxide trading only works in the United States because the powerful Environmental Protection Agency is there to enforce it.

Some critics also ask who would prevent governments from interfering with the market to defend their regional and national interests.

Trading would “require governments to relinquish a huge amount of power,” says Parson. “International trading is the way to go — but it is naive to think that we have worked out how to do it.”