Almost 200 countries on Saturday 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 a meeting widely criticised as lacking urgency.
Governments agreed that a new deal in 2015 would consist of a patchwork of national offers to curb emissions, and would blur a 20-year-old distinction between the obligations of rich and poor nations.
The two-week meeting also set up a new 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.
Still, many said Warsaw 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 meeting 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 in the wake of the Fukushima disaster.
Environmentalists walked out on Thursday, exasperated by lack of progress. Rich nations are preoccupied with reviving their weak economies rather than climate change.
"The actions that have been agreed are simply inadequate when compared with the scale and urgency of the risks that the world faces from rising levels of greenhouse gases, said Nicholas Stern of the London School of Economics.
The negotiators agreed that a new global deal, due to be agreed in Paris 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 now, rich nations that have emitted most greenhouse gases since the Industrial Revolution have been expected to take the lead with "commitments" to cut emissions while the poor have been granted less stringent "actions".
"In the old system you had this firewall between commitments and actions, now there is one word for all," European Commissioner Connie Hedegaard said. "There are many ways to Paris that would be more beautiful and faster."
The Warsaw deal called on those nations able to do so to put forward their plans by the first quarter of 2015 to give time for a review before a summit in Paris at the end of the year.
Under the last climate pact, the Kyoto Protocol, only the most developed countries were required to limit their emissions - one of the main reasons the United States refused to accept it, saying rapidly growing economies like China and India should also take part.
Until Saturday, the only concrete measure to have emerged in Warsaw after two weeks 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 $100 billion a year after 2020 from $10 billion 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.