A handful of major states including Australia have resisted pressure to ramp up efforts to combat global warming as a UN climate summit ground to a delayed close.
Their stance at the COP25 talks in Madrid prompted sharp criticism from smaller countries and environmental activists.
The talks were viewed as a test of governments' collective will to heed the advice of scientists to cut greenhouse gas emissions more rapidly in order to prevent rising global temperatures from hitting irreversible tipping points.
But the conference, in its concluding draft, endorsed only a modest declaration on the "urgent need" to close the gap between existing emissions pledges and the temperature goals of the landmark 2015 Paris climate agreement.
"We are of mixed emotions," said Chile's environment minister Carolina Schmidt, who served as president of the talks, after final decisions were made on Sunday.
Brazil, China, Australia, Saudi Arabia and the US had led resistance to bolder action, delegates said.
"These talks reflect how disconnected country leaders are from the urgency of the science and the demands of their citizens in the streets," Helen Mountford of the World Resources Institute think-tank said.
"They need to wake up in 2020."
The gathering had been due to end at the two-week mark on Friday but ran on for two extra days - a long delay even by the standards of often torturous climate summits.
Chile had earlier triggered outrage after drafting a version of the text that campaigners complained was so weak it betrayed the spirit of the Paris Agreement.
The process set out in that deal hinges on countries ratcheting up emissions cuts next year.
The final draft did acknowledge the "significant gap" between existing pledges and the temperature goals adopted in 2015.
Nevertheless, it was still seen as a weak response to the sense of urgency felt by communities around the world afflicted by floods, droughts, wildfires and cyclones that scientists say have become more intense as the earth rapidly warms.
"COP25 demonstrated the collective ambition fatigue of the world's largest (greenhouse gas) emitters," Greenpeace East Asia policy advisor Li Shuo said.
The Madrid talks became mired in disputes over the rules that should govern international carbon trading, favoured by wealthier countries to reduce the cost of cutting emissions.
Brazil and Australia were among the main holdouts, delegates said, and the summit deferred big decisions on carbon markets for later.
"As many others have expressed, we are disappointed that we once again failed to find agreement," Costa Rica climate official Felipe De Leon said.
Smaller nations had also hoped to win guarantees of financial aid to cope with climate change.
The Pacific island of Tuvalu accused the US, which began withdrawing from the Paris process last month, of blocking progress.
"There are millions of people all around the world who are already suffering from the impacts of climate change," Tuvalu's representative Ian Fry told delegates.
"Denying this fact could be interpreted by some to be a crime against humanity."
Australian Associated Press