Climate treaty's 'minimal' impact

Most of the reductions had been assigned to the US

By BBC science correspondent Richard Black

As the United Nations climate conference in Marrakech draws to a close, a new analysis just published in the journal Science concludes that the impact of the re-modelled Kyoto Protocol on greenhouse gas emissions will be minimal.

Over the four years of its existence, the original Kyoto Protocol has been changed in many ways - not least by US President George Bush's decision earlier this year to withdraw.

Other major modifications came at the Bonn meeting in July, which allowed countries to meet their individual targets largely by planting forests to absorb carbon dioxide from the atmosphere, rather than reducing their emissions.

The final agreement in Bonn, according to environmental campaigners, committed industrialised nations to cut their net emissions of greenhouse gases by only about 2% of their 1990 levels by 2012.

The original protocol, agreed in 1997, committed signatories to cuts more than twice as great - an average of 5.2% on 1990 emissions.

New analysis

But the new analysis by William Nordhaus, an economics professor at Yale University in the United States and a former presidential advisor, says the actual impact will be much lower.

"Roughly speaking, three-quarters of the emissions reductions under the Kyoto Protocol as originally designed were assigned to the United States. So, without the United States, I estimate that emissions reductions under Kyoto-Bonn will be about 1.5% lower than a no-control scenario," he said.

Other scientists believe Professor Nordhaus's figures to be accurate, without sharing his conclusion that unless the US comes back on board, the treaty is a worthless exercise.

Many scientists, environmentalists and politicians believe that the real value of Kyoto lies not in its immediate impact on greenhouse gas concentrations, but in that it sets a precedent for concerted global action on climate change.

Several important countries, notably those of the European Union, have indicated they will seek to ratify the protocol early next year.

This will allow the United Nations process to move on to the next stage - agreeing on future targets for deeper emissions cuts, and bringing developing countries into the arena.