Delegates from nearly 200 states finalise a common rulebook designed to deliver goals of limiting a rise in global temperature to well below two degrees Celsius.
Nations on Sunday struck a deal to implement the landmark 2015 Paris climate treaty after marathon UN talks that failed to match the ambition the world's most vulnerable countries need to avert dangerous global warming.
"Putting together the Paris agreement work programme is a big responsibility," said COP24 president Michal Kurtyka as he gavelled through the manual following talks in Poland that ran deep into overtime.
"It has been a long road. We did our best to leave no-one behind."
TRT World's Reagan Des Vignes reports.
But environmental groups said the package agreed in the Polish mining city of Katowice lacked the bold ambition needed to protect states already dealing with devastating floods, droughts and extreme weather made worse by climate change.
"We continue to witness an irresponsible divide between the vulnerable island states and impoverished countries pitted against those who would block climate action or who are immorally failing to act fast enough," executive director of Greenpeace Jennifer Morgan said.
The final decision text was repeatedly delayed as negotiators sought guidelines that are effective in warding off the worst threats posed by our heating planet while protecting the economies of rich and poor nations alike.
"Without a clear rulebook, we won't see how countries are tracking, whether they are actually doing what they say they are doing," Canada's Environment Minister Catherine McKenna told AFP.
TRT World spoke with Sven Harmeling, global policy lead on climate change for the humanitarian agency CARE International, for more.
At their heart, negotiations were about how each nation funds action to mitigate and adapt to climate change, as well as how those actions are reported.
Developing nations wanted more clarity from richer ones over how the future climate fight will be funded and pushed for so-called "loss and damage" measures.
This would see richer countries giving money now to help deal with the effects of climate change many vulnerable states are already experiencing.
Another contentious issue was the integrity of carbon markets, looking ahead to the day when the patchwork of distinct exchanges - in China, the Europe Union, parts of the United States - may be joined up in a global system.
"To tap that potential, you have to get the rules right," said Alex Hanafi, lead counsel for the Environmental Defense Fund in the United States.
"One of those key rules – which is the bedrock of carbon markets – is no double counting of emissions reductions."
The Paris Agreement calls for setting up a mechanism to guard against practices that could undermine such a market, but finding a solution has proved so problematic that the debate has been kicked down the road to next year.
'System needs to change'
One veteran observer told AFP Poland's presidency at COP24 had left many countries out of the process and presented at-risk nations with a "take it or leave it" deal.
Progress had "been held up by Brazil, when it should have been held up by the small islands. It's tragic."
One of the largest disappointments for countries of all wealths and sizes was the lack of ambition to reduce emissions shown in the final COP24 text.
Most nations wanted the findings of the Intergovernmental Panel on Climate Change (IPCC) to form a key part of future planning.
It highlighted the need for carbon pollution to be slashed to nearly half by 2030 in order to hit the 1.5C target.
But the US, Saudi Arabia, Russia and Kuwait objected, leading to watered-down wording.
The final statement from the Polish COP24 presidency welcomed "the timely conclusion" of the report and invited "parties to make use of it" -- hardly the ringing endorsement many nations had called for.
"There's been a shocking lack of response to the 1.5 report," Morgan told AFP. "You can't come together and say you can't do more!".
With UN talks well into their third decade sputtering on as emissions rise remorselessly, activists have stepped up grassroots campaigns of civil disobedience to speed up action on climate.
"We are not a one-off protest, we are a rebellion," a spokesman for the Extinction Rebellion movement, which disrupted at least one ministerial event at the COP, told AFP.
"We are organising for repeated disruption, and we are targeting our governments, calling for the system change needed to deal with the crisis that we are facing."