International negotiators at the Lima climate change talks have agreed on a plan to fight global warming that would for the first time commit all countries to cutting their greenhouse gas emissions.
The plan, agreed at United Nations talks on Sunday, was hailed as an important first step towards a climate change deal due to be finalised in Paris next year.
â€œAs a text itâ€™s not perfect, but it includes the positions of the parties,â€ said Manuel Pulgar-Vidal, the Peruvian environment minister, who presided over the talks.
However, negotiators acknowledged they had put off the most difficult decisions for later.
Campaigners said the plan was far too weak to limit warming to the internationally agreed limit of 2C above pre-industrial levels, or to protect poor countries from climate change.
â€œItâ€™s definitely watered down from what we expected,â€ said Alden Meyer of the Union of Concerned Scientists.
They also warned negotiators had left too many contentious issues unresolved before the deadline for reaching a deal in Paris. â€œThe countdown clock to Paris is now ticking. Countries had the chance to give themselves a head start on the road to Paris but instead have missed the gun and now need to play catch up,â€ said Mohammed Adow, Christian Aidâ€™s senior climate change advisor.
But after a difficult negotiation â€“ which over-ran by two daysâ€“ officials said they were satisfied with the outcome.
â€œIt was contentious along the way but it fundamentally accomplished what we wanted it to,â€ Todd Stern, the US State Departmentâ€™s climate change envoy, said.
The five-page text agreed on Sunday â€“ now officially known as the Lima Call for Climate Action â€“ represents the embryonic phase of the deal due to be delivered in Paris.
As sketched out in Lima, all countries, rising economies as well as rich countries would pledge action on climate change.
Wealthy countries would help developing countries fight climate change, by investing in clean energy technology or offering climate aid.
Countries already threatened by climate change â€“ such as small island states which face being swallowed up by rising seas â€“ were promised a â€œloss and damageâ€ programme of financial aid.
The all-inclusive nature of the emissions cuts constitutes a break with one of the defining principles of the last 20 years of climate talks â€“ that wealthy countries should carry the burden of cutting carbon dioxide emissions.
â€œI think for the first time ever the world can contemplate a global deal applicable to all and Lima has helped that process,â€ the UKâ€™s energy and climate change secretary, Ed Davey, said.
If all goes well, China, whose emissions have overtaken the US, will as part of the agreement formally pledge to cut its greenhouse gas emissions, as will India, Brazil and other rising economies.
But much remains uncertain about the prospects of a strong deal emerging from Paris â€“ not least because of the problems that arose during the negotiations in Lima.
The Lima negotiations had opened on 1 December amid a spirit of optimism following an agreement last month between the US and China to cut carbon pollution.
But it soon became apparent that the US-China deal on its own would have no effect on bridging the perennial dividing line of climate negotiations â€“ the responsibility for cutting greenhouse gas emissions.
The talks over-ran by two days because of clashes over which countries should carry the burden of fighting climate change.
There were also disputes over climate finance. Wealthy countries were accused of failing to live up to their earlier promises of mobilising billions to help developing countries fight climate change.
But after a day of brinkmanship on Saturday â€“ with Stern warning of a â€œmajor breakdownâ€ – the deal was done.
â€œWe got what we wanted,â€ Prakash Javadekar, Indiaâ€™s environment minister, said.
But much now remains to be done if the broad outlines agreed at Lima are to materialise in a full-fledged climate deal.
The US, China, and the European Union have already come forward with pledges for cutting greenhouse gas emissions after 2020.
Under the plan, countries are due to come forward by March 2015 with their proposed emissions reductions targets.
The United Nations would then weigh up those pledges and determine whether the collective action was enough to limit warming to 2C.
But much remains vague or poorly defined. The countries put off decisions about the legal structure of the agreement, and deferred decisions about ensuring a flow of finance to developing countries.
The biggest issue left unresolved for Paris is the burden for cutting greenhouse gas emissions. The draft text retains language of â€œcommon but differentiated responsibilitiesâ€ that has over the years given developing countries a pass on cutting emissions. That language remains in the text although with a rider â€œin light of different national circumstancesâ€. Stern acknowledged to reporters the issue was likely to come up again at Paris.
And the text adopted on Sunday no longer makes it mandatory for countries to provide detailed information about their prospect reductions targets.
Campaigners said that would make it increasingly difficult to be sure the deal would manage to keep warming within the 2 degree threshold.