Environment and Climate Change Minister Jonathan Wilkinson, centre, poses with members of the Canadian negotiating team in Madrid on December 15, 2019.
Participants failed to reach agreement on the rules, however, despite a two-day extension. And it felt disconnected from youth activists led by Sweden's Greta Thunberg, and from indigenous, human rights and science advocates who besieged the conference venue demanding action in line with an emergency.
Sara Shaw, climate justice and energy programme coordinator for Friends of the Earth International said: 'Just as we thought the slow pace and weak ambition shown at the climate talks couldn't get any worse, along comes COP25.
Australia's Emissions Reduction Minister Angus Taylor, far left, with other delegates to the COP 25. I attended the conference as an observer.
Chinese foreign ministry spokesman Lu Kang, whose government cooperated closely with former U.S. President Barack Obama's administration on climate change, said all countries should "move with the times".
Much was riding on the outcome in Madrid.
Emissions trading: Article 6 of the Paris Agreement envisioned a system for swapping emissions credits between countries.
Delegates were supposed to draw up these rules at COP24 a year ago in Poland but action was postponed to COP25.
No consensus was reached.
The argument will not be easily resolved.
Chile's Environment Minister Carolina Schmidt, who chaired the meeting, said she was "sad" no deal had been reached on the rules for global trading in carbon emissions permits.
It was an inglorious end to a summit that had started with the hashtag "time for action" but failed to see any, despite closed door negotiations that delayed the final plenary session by 40 hours - another dubious record.
The Paris accord was meant to establish the rules for carbon trading on a global scale.
Steam rises a German coal-fired power plant.
The conference also discussed measures to strengthen the governance and finance arrangements of the Warsaw International Mechanism, a measure created to compensate poor nations for climate damage. The US, which will soon exit the Paris Agreement, played a key role in stymieing progress.
Going further, in Madrid the USA delegation also vetoed agreement that the United Nations mechanism to deal with loss and damage be supervised by both UNFCCC and the countries who had ratified the Paris agreement.
The lack of a robust outcome to reinforce the Paris agreement raises the stakes for the next big climate summit, in Glasgow in November 2020.
A group of countries called the High Ambition Coalition, however, consisting of Ethiopia, small island states such as Fiji, New Zealand, Costa Rica, and the European Union, vowed to fight for a stronger outcome. However, the final text is weaker than the previous version.
Under the Paris accord, countries are supposed to regularly review their national emissions reduction targets and increase them if necessary.
The results are disheartening.
In term of finance, it "urges" scale up of support by developed countries and other Parties in a position to do so, as well as private and non-governmental organisations, funds and other stakeholders; but then only invites the Green Climate Fund (GCF) Board to continue providing resources for loss and damage, and invites it to take into account, within its mandate, the strategic work streams of the WIM executive committee.
There are millions of people all around the world who are already suffering from the impacts of climate change. At the plenary session, the delegate from Nicaragua described the United States action as a "crime against humanity".