Environment

President Barack Obama has given a major boost to next month's UN climate change negotiations in Copenhagen by offering firm targets for cuts in US greenhouse gas emissions. The move, announced today, has been widely welcomed by climate change campaigners. But although they may seem generous, the proposed targets are in fact far from what developing nations and climate scientists have called for.

Obama said the US was prepared to cut its emissions of greenhouse gases by 17 per cent by 2020 and by 83 per cent by 2050 "in the context of an overall deal in Copenhagen that includes robust mitigation contributions from China and the other emerging economies".

At first glance, that sounds similar to commitments made by other wealthy nations. The European Union, for instance, is aiming to cut its emissions by 20 per cent cut by 2020 and 80 per cent by 2050. But the US president is measuring his cuts against 2005 emissions; most other nations use 1990 as a baseline.

The difference is subtle but significant: US emissions grew by almost 15 per cent between those dates. Using 1990 as a baseline, Obama's pledge translates into a cut of around 4 per cent.

That is well short of the 25 to 40 per cent cuts that the Intergovernmental Panel on Climate Change says are required from developed nations to avoid the most dangerous consequences of climate change.

More cuts may come

The US may, however, achieve bigger cuts than Obama's statement makes apparent. It is likely that the pledge relates to a scheme to limit emissions from specific industries, such as the energy sector. Alexia Kelly, a climate policy expert at the World Resources Institute in Washington DC, points out that other domestic policies, such improvements in vehicle fuel efficiency, will bring further reductions.

The White House announcement does not say how the cuts will be achieved. The House of Representatives has, however, passed a bill containing similar reductions, and the Senate is considering legislation with a slightly more ambitious target. The presence of those bills will at least allow Obama to point to domestic action when negotiating at Copenhagen. He also has the option of bypassing Congress and imposing cuts through existing legislation, such as the Clean Air Act. "I suspect that it will be a combination of the two," says Kelly.

Obama's pledge also contains interim targets for the US: a 30 per cent cut below 2005 levels by 2025 and a 42 per cent cut by 2030. This addresses one major complaint from developing nations, which have been calling for a more detailed reductions timetable for the next few decades.

Will all this add up to enough incentives to bring China and India – two major polluters that have so far resisted calls to regulate their emissions – on board a global deal? "That we don't know," says Kelly. With the UN climate negotiations less than a fortnight away, we may not have to wait long to find out.

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