Almost 200 countries have kept alive hopes for a global deal in 2015 to fight climate change after overcoming disputes on greenhouse gas emissions cuts and aid for poor nations at talks in Poland.
Governments agreed that a new deal in 2015 would consist of a patchwork of national contributions to curb emissions that could blur a 20-year-old distinction between the obligations of rich and poor nations.
The two-week meeting also created a Warsaw International Mechanism to help the poor cope with loss and damage from heatwaves, droughts, floods, desertification and rising sea levels - although rich nations refused to pledge new cash.
Many said trhe deal had fallen short of what was needed.
"We did not achieve a meaningful outcome," said Naderev Sano, a Philippines delegate who had been fasting throughout the talks to urge action in sympathy with victims of Typhoon Haiyan, which killed more than 5,000 people.
No major nation offered tougher action to slow rising world greenhouse gas emissions and Japan backtracked from its carbon goals for 2020, after shutting down its nuclear industry after the Fukushima disaster.
Environmentalists walked out on Thursday, exasperated by the lack of progress. Rich nations are considered to be preoccupied with reviving their weak economies rather than climate change.
"It is abundantly clear that we still have a long way to go," said Christiana Figueres, the UN climate chief.
Negotiators were on course for a 2015 summit in Paris but not on track for limiting global warming to an agreed ceiling of 2 degrees Celsius above pre-industrial times to avoid dangerous change, she said.
In September, the UN panel of climate experts raised the probability that man-made emissions of greenhouse gases, mainly from burning fossil fuels, were the main cause of warming since 1950 to 95%, from 90% in a previous assessment.
Delegates in Warsaw agreed that a new global deal, due to be struck in Paris in 2015 and to enter into force from 2020, would be made up of what they called "intended nationally determined contributions" from both rich and poor nations.
Until Saturday, the only concrete measure to have emerged in Warsaw was an agreement on new rules to protect tropical forests, which soak up carbon dioxide as they grow.
Developed nations, which promised in 2009 to raise aid to €80bn a year after 2020 from €8bn a year in 2010-12, rejected calls to set targets for 2013-19.
A draft text merely urged developed nations to set "increasing levels" of aid.