MADRID - A marathon UN summit wrapped up Sunday with little to show, squeezing hard-earned compromises from countries over a global warming battle plan that fell well short of what science says is needed to tackle the climate crisis.

The COP25 deal "expresses the urgent need" for new carbon cutting commitments to close the gap between current emissions and the Paris treaty goal of capping temperature at below two degrees, host country Spain said in a statement.

"Today the citizens of the world are asking for us to move ahead faster and better, in financing, adaptation, mitigation," Carolina Schmidt, Chilean environment minister and President of COP25, told the closing plenary.

Following a year of deadly extreme weather and weekly strikes by millions of young people demanding action, negotiations in Madrid were under pressure to send a clear signal that governments were willing to double down.

The summit -- moved at the last minute from Chile due to unrest -- at times teetered on the brink of collapse as rich polluters, emerging powerhouses and climate-vulnerable nations groped for common ground in the face of competing national interests.

"Based on the adopted text, there is a glimmer of hope that the heart of the Paris Agreement is still beating," said Mohamed Adow, Director of Power Shift, referring the treaty inked in the French capital.

"But its pulse is very weak."

Negotiators from nearly 200 nations came to Spain's capital with the aim of finalizing the rulebook for the 2015 agreement, which enjoins nations to limit global temperature to below two degrees Celsius (3.6 Fahrenheit).

With the accord set to become operational next year, it had been hoped COP 25 would show the world that governments would be moved by protests, irrefutable science, and deadly storms and wildfires that marked 2019 to redouble their efforts.

But greater ambition -- how far each country is willing to slash carbon emissions or assist less wealthy peers to do likewise -- has largely failed to materialize.

Veteran observers of UN climate talks were stunned by the state of play.

"Never have I seen such a disconnect between what the science requires and what the climate negotiations are delivering in terms of meaningful action," said Alden Meyer, director of strategy and policy at the Union of Concerned Scientists and a 28-year veteran of the climate process.

"Most of the world's biggest emitting countries are missing in action and resisting calls to raise their ambition."

The push for a strengthening of voluntary carbon cutting plans is led by small-island and least-developed states, along with the European Union.

China and India, the world's No. 1 and No. 4 carbon emitters, made it clear they see no need to improve on their current emissions reduction plans, which run to 2030.

These emerging giants chose instead to emphasize the historical responsibility of rich nations to lead the way and provide financing to poor countries.

"Major players who needed to deliver in Madrid did not live up to expectations," said Laurence Tubiana, CEO of the European Climate Foundation and, as France top negotiator, a main architect of the Paris Agreement.

"But thanks to a progressive alliance of small island states, European, African and Latin American countries, we obtained the best possible outcome, against the will of big polluters." -AFP