support from unexpected quarters has come as a welcome surprise for developing countries which have demanded that international climate change negotiations be based on the principle of equity. A study by the uk 's Royal Commission on Environmental Pollution ( rcep ) says that an effective, enduring and equitable climate agreement will require greenhouse gas ( ghg ) emission quotas to be allocated to nations on a simple and equal per capita basis. This stand is similar to that taken by the Indian government and the G77 block of developing countries in global climate negotiations over the past decade.

The uk government will respond formally to the report. "That can take up to two years, but we hope it will be within a year," says Nicholas Schoon, press officer to the rcep ."The government is due to produce this autumn the final version of its climate change strategy, covering the period up to 2010. We hope they will take our report into account." The government response will explain how existing policies and programmes can be reconciled with the rcep suggestions.

Previous reports by the commission have influenced national policy, Schoon points out. Over 30 years of its existence, the commission's most influential reports have concerned exposure to lead, nuclear power, integrated pollution control and transport.

While it remains to be seen how influential the report will turn out to be, Schoon notes that it has evoked considerable media interest. It will be a major shift in policy if the government accepts the recommendations. Like most developed countries in Europe and North America, the uk has held a position of indifference towards the South's demand of calculating ghg emissions on a per capita basis as each human being has an equal entitlement to the atmosphere.

As a system of per capita entitlements cannot enter into force immediately, the report proposes 'contraction and convergence'. "Initially, emission quotas are :s is' - approximately proportional to each country's income," explains Aubrey Meyer of the London-based Global Commons Institute, a leading advocate of this approach. "Over an agreed period, however, all countries will converge on the same allocation per head of their population in a base year, which has to be agreed upon." This means the quotas of developed countries fall year by year, while those of developing countries rise until all nations emit equal amounts of greenhouse gases per head ( convergence ). The rcep report proposes 2050 as the year for convergence. It will also be the cut-off date for national populations, that is, further changes in a country's population would not affect its emission quota.

From then on, after convergence has been achieved, the quotas of all nations would decline together at the same rate ( contraction ). According to the report, commentators on climate diplomacy have identified contraction-and-convergence as the leading contender among the various proposals for allocating emission quotas to nations in the long run. To make an agreement based on per capita allocation quotas more feasible, the report supports emissions trading between nations. Countries that wish to emit ghg in excess of their respective quotas would be able to purchase unused quotas at prices that incline other countries to emit less than their quotas.

The commission also recommends that the international community adopt an upper limit for carbon dioxide concentration in the atmosphere of 550 parts per million by volume (ppmv).Current global concentration levels stand at about 370 ppmv. A target of 550 ppmv is not entirely safe because, according to the international scientific community, even stabilisation at 450 ppmv would result in a temperature rise of 0.71C and a corresponding 10-65 cm rise in sea level.

If the contraction-and-convergence approach and the target of 550 ppmv are adopted, the uk 's carbon dioxide ( co2 ) emissions will have to be reduced by almost 60 per cent from their current level by mid-century, and by almost 80 per cent by 2100. To achieve this, the rcep recommends reductions in energy demand and a large deployment of renewable energy sources, both of which can be achieved partly through the introduction of a carbon tax.

The commission calls on the uk to play a forceful and leading role in international climate negotiations, and it is not only because the country has a moral imperative to do so. It is also because the greater the number of countries that are hesitant, the smaller the chances of concerted global action against climate change. Already, it warns, there is the danger that the commitments made in Kyoto in 1997 will not be met by developed countries. The report concludes that if the uk does not show serious in doing its own bit, it cannot expect other nations to do theirs, least of all poor countries.