the agreement struck at the copenhagen climate change summit will not be enough to stave off dangerous levels of climate change, according to numerous analyses.

that is because, due to the accord's limited nature, countries can stick to the lower end of the ranges of commitments they made before the conference to reduce their greenhouse gas emissions.

under pressure from domestic interests, governments might even seek to reduce their pledges by their self-imposed deadline of the end of next month.

if commitments remain at the upper end of the scale, the world would be within a whisker of meeting scientific estimates of the amount of reductions needed, according to an analysis headed by lord stern, the former world bank chief economist and prominent climate change analyst.

 but if they are at the bottom of the scale, the outlook for the planet is likely to be much more ominous.

the copenhagen accord's weak legal status is another impediment in trying to persuade nations to be more ambitious with their commitments. because of opposition from a few latin american governments, countries have agreed within the context of the united nations negotiations only to “note” the accord, rather than sign up to it. that makes it harder to press countries into stiffening their promises.

barack obama, the us president, acknowledged as much. he hailed the pact as “the first time in history all major economies have come together to accept their responsibility” on climate change. but he added: “we know that this progress alone is not enough.”

“we're going to have to build on the momentum that we've established here in copenhagen to ensure that international action to significantly reduce emissions is sustained and sufficient over time.”

the us has pledged to cut its emissions by 17 per cent by 2020, compared with 2005 levels, but that is conditional on domestic legislation being passed. the european union has vowed to cut its emissions by 20 per cent, compared with 1990 levels, by the same time.

most developing countries, including china and india, have agreed only to curb the future growth of their emissions. but many, rather than committing themselves to a single target, have pledged a range. the eu will deepen its promise to 30 per cent below 1990 levels if other countries also agreed ambitious targets. china is committed to reducing the growth in its carbon dioxide output per unit of gross domestic produce by 40 to 45 per cent by 2020.

when all of these ranges are added up, the potential difference in emissions cuts is huge. the european climate foundation estimates that if all countries went to the upper end of their ranges, emissions would be reduced by 17 per cent from 1990 levels, by 2020. but if countries stuck to the lower end of their ranges, the cut would be only 3 per cent.

that gives negotiators plenty to play for in the next month. “there will be a lot of discussions going on, trying to persuade countries to go to their upper targets,” said one dev­eloped country's negotiator.

but the omens are not good, said bernice lee, research director for energy and the environment at the royal institute of international affairs. “none of the major parties moved out of their comfort zones in . . . negotiations. they stuck to their opening offers