Last minute objections from India and China halted a commitment to end coal use and subsidies for fossil fuels as countries reached a deal on the climate crisis to keep within reach the goal of limiting global heating to 1.5ºC.
The Glasgow deal, reached after two weeks of hard-fought negotiations, included rules for a global carbon market and financial commitments to help countries adapt to climate change.
"The approved texts are a compromise. They reflect the interests, the conditions, the contradictions and the state of political will in the world today," UN Secretary-General António Guterres said in a statement. "They take important steps, but unfortunately the collective political will was not enough to overcome some deep contradictions."
The approved texts are a compromise. They reflect the interests, the conditions, the contradictions and the state of political will in the world today."
"Not everyone gets to make choices that actually affect an entire planet. We are privileged today to do exactly that," said United States Special Climate Envoy John Kerry.
In the final hours of the summit, a plan to approve the COP26 text was thrown off track when India and China objected to the phrase about the "phase out" of unabated coal power, referring to power plants that do not capture carbon dioxide emissions, as well as all fossil fuel subsidies. After a huddle between the US, EU and China, a compromise was reached on a pledge to phase "down" rather than phase "out" coal.
The agreement, reached late on Saturday night, drew sharp criticism from those seeking a promise to end the use of coal power altogether, including many smaller island nations.
"It will be too late for the Maldives," Aminath Shauna, environment minister of the Maldives, said, adding: "What is balanced and pragmatic to other parties will not help the Maldives adapt in time."
COP26 President Alok Sharma said the deal struck in the Glasgow climate pact was a "fragile win" and urged China and India to "justify" their actions to nations that are more vulnerable to the effects of global warming.
Jennifer Morgan, head of Greenpeace International, said the outcome of COP26 was "meek" and "weak" but still sent a signal about ending the era of coal. "Glasgow was meant to deliver on firmly closing the gap to 1.5ºC and that didn't happen," she said.
Prime Minister Boris Johnson acknowledged his "delight" at reaching a new deal but added that the result was "tinged with disappointment" after the language on coal was altered later on.
Despite criticism, the deal is seen as a landmark of sorts in that it is the first explicit mention of fossil fuels in a UN climate agreement.