In the end, there was a deal of sorts. Yet, as the delegates finally left the latest UN climate talks in Madrid, they did so not just exhausted but, on the whole, deflated.

COP25, again postponed a decision on the final section of the landmark Paris Climate Agreement, Article 6, to next year's meeting in Glasgow.

After a fortnight of intense talks and two consecutive sleepless nights, understandable tiredness led to confusion as the final plenary began. 

Delegates were tasked with considering, and then approving, different sections of the draft agreement before it was frozen.

^{CGTN's Guy Henderson outlines what was agreed - and what was not agreed}

And yet, proceedings were repeatedly held up, with country after country complaining they were unable to pass judgment – repeated technical errors meant online documents were incorrectly named, making them hard to locate. Some reported mistakes in the texts.

With that issue ironed out, there was then deadlock on a far more important one – rules for a carbon market, seen as vital for reducing emissions.

Brazil still refused to commit to stricter rules to prevent both buyer and seller of a carbon credit counting a single unit in their emissions reduction efforts – so-called "double-counting." 

The South American nation also wanted to earn "carry-over credits," which would allow countries to earn tradable carbon credits from efforts made to reduce emissions from the pre-Paris Kyoto Protocol era.

For most negotiators, that amounted to "greenwashing." But all decisions here are by consensus. A majority was not enough to push those stricter rules through.

Instead, a group of what now numbers 31 countries – including large economies such as Germany and the Netherlands – formed a coalition of the willing, signing on to what have been dubbed "The San Jose Principles."

These include commitments to discount pre-2020 carbon credits, and rule out double-counting. 

Still, as one of the European Union delegates who took the floor during the final session acknowledged, they will not on their own be sufficient to push the world towards implementing the Paris Agreement. 

"We hope we will be able to obtain operational rules next year to move towards carbon markets," he said.

These were not just the longest UN climate talks, they were also some of the most fractious. That is not to say there was no progress. 

All participants did at least agree in principle to scale up financial support for countries that will be worst affected by climate change.

There was no solid commitment to new funds, though. Some of the nations most vulnerable to the growing climate crisis expressed particular alarm that the US wanted to sit on the body overseeing that process, despite the fact it is pulling out of the Paris Agreement.

Small Pacific island states such as Tuvalu have long complained that the developed nations primarily responsible for global warming continue to show a lack of willingness to help those most vulnerable to its effects.

Their worry now is that Washington – which blocked further progress on this issue – could use its considerable clout to prevent any money from being distributed.

^{Clare Nullis, from the World Meteorological Organization, outlines the need for action}

Tuvalu's Ian Fry told the conference: "There are millions of people all around the world who are already suffering from the impacts of climate change. Denying this fact could be interpreted by some to be a crime against humanity."

The final document did also include an obligation for all nations to bolster their national greenhouse gas emissions reductions plans over the next 12 months.

An earlier version of the draft text omitted such ambitions, which was another primary cause for these negotiations dragging on so long. Several European nations refused to leave until the language was strengthened.

Still, there is widespread disappointment, with campaign groups pointing fingers at just a handful of participants.

"US President Trump and President Bolsonaro from Brazil have undermined these negotiations," Mark Kaiser from Greenpeace told the Reuters news agency as he left.

"If they are going to continue so next year, we need a different answer from strong economies like the European Union, together with China, together with India, to come up with a new narrative of hope for the young people out there."

COP 26 in Glasgow will be a crucial one. If it ends as COP 25 Madrid has, the very credibility of the Paris Agreement could be at stake.

Read more:

Why we need gender equality in climate change action

Germany's negotiator at COP25: All big emitters must achieve targets