Madrid: UN Secretary-General Antonio Guterres on Sunday said he was disappointed with the outcome of the UN Climate Change Conference or COP25 that ended in this Spanish capital almost 44 hours beyond the scheduled closing time.
Climate experts said the two-week long talks produced a weak gesture toward raising climate targets and failed to agree for the second year in a row on rules to govern carbon markets.
"I am disappointed with the results of COP25," Guterres said in a statement.
The international community lost an important opportunity to show increased ambition on mitigation, adaptation and finance to tackle the climate crisis, he said.
"But we must not give up, and I will not give up."
"I am more determined than ever to work for 2020 to be the year in which all countries commit to do what science tells us is necessary to reach carbon neutrality in 2050 and a no more than 1.5 degree temperature rise," the Secretary-General, who devoted much of his time in the summit, added.
Climate negotiators said governments failed dismally to respond to the unfolding global climate crisis despite clear warnings from scientists through 2019, record levels of protests and severe climate impacts.
They said the talks fell victim to major differences between countries that were proving hard to resolve.
Observers in Madrid blamed G20 countries for the poor outcome, with the US, Brazil, Australia, Saudi Arabia and major oil, gas and coal companies implicated in undermining climate ambition.
Leading economies were faulted for their complacency -- failing to deliver more support to vulnerable nations in the face of brutal impacts and push for a tougher collective response in 2020 -- when new climate plans are mandated under the Paris Agreement.
The EU tried to play its role as bridge-builder between developing and developed countries. However, it will take a major diplomatic push and bigger leadership alliance to deliver substantial outcomes at the next COP26 in Glasgow.
Aarti Khosla, Director, Climate Trends, who was following the climate negotiations, said the impacts of not acting adequately on climate change are clear and visible not just in the global south, but also in the global north.
"Yet, the recently concluded COP shows that the political will to act is absolutely missing across governments. Citizens of the world, from an eight years old to a 102 years old, have poured out onto the streets to call on their governments for ambitious actions," she said.
EU announced an ambition for 2050 leaving out what it can do in 2030.
China, as the largest global emitter has not felt the need to take leadership.
India with its largest renewables programme of any country, has the opportunity of moving away from coal which it hasn't seized, said an observer.
Laurence Tubiana, CEO European Climate Foundation and Paris Agreement Architect, said: "The result of this COP25 is really a mixed bag, and a far cry from what science tells us is needed. Major players who needed to deliver in Madrid did not live up to expectations, 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."
The Paris Agreement saved but huge work needed to make Glasgow summit a success, said Britain-based Christian Aid.
It Global Climate Lead Katherine Kramer said: "The UK now has a gargantuan task of overseeing a successful climate summit in Glasgow next year. That meeting is supposed to be the moment the world responds to the climate crisis by strengthening the pledges made in the Paris Agreement. To avoid failure, the UK will need to put its own house in order, in creating and implementing policies to rapidly reduce its own emissions."
"It will also need to deploy its diplomatic skills to create an outcome that responds to the demands of both science and people."
With 197 parties, the the UN Framework Convention on Climate Change (UNFCCC) has near universal membership and is the parent treaty of the 2015 Paris Climate Change Agreement, which comes into effect in January 2021