Countries had to dismount from plenty of high horses as negotiators sought a final agreement in the last few days of the conference. Many countries' red lines were crossed in the interests of painful compromises. But the conference ended in high drama when India stubbornly refused to get down off its particular steed.

The issue was coal. Every other country had accepted a line in the final agreement calling for "the phasing-out of unabated coal" (that is, coal used without carbon capture and storage technology). But India would not. Even after the conference had to be adjourned because of its refusal, and even after delegates were called back two hours later assuming a deal had been done, India objected again, proposing a further amendment to the now completed text. "Phasing out," India said, should be replaced by "phasing down". The British chair of the conference, Alok Sharma, choked back tears as he apologised for the failure of the process, to much sympathy from delegates.

India's late obstructionism highlighted both the power and limitations of these UN climate conferences. On the one hand the fifth-largest economy in the world cared enough about the precise wording of the agreement to face down the anger of 195 other nations. There were many things in the text they didn't like either, but had accepted in the spirit of compromise required to reach agreement. On the other it will make practically no difference to anything that actually happens in the real world beyond the conference hall. Though Greenpeace and other climate campaigners hailed the first ever mention of getting rid of fossil fuels in a COP decision, the text is entirely symbolic. Without a date by when it must be done, "phasing out"' coal has little practical meaning, and "phasing down" means pretty much the same thing.

Part of the reason we know it was only symbolic was that Australia had accepted the "phasing out" text, even though the government has no plans to end coal use at all. Poland, another coal-dependent nation, has agreed to a phase-out, but not till 2049. In practice, all three countries will have to end their use of coal well before that date if the Paris goal of limiting global heating to no more than 1.5 degrees above pre-industrial times is to be achieved.

The 1.5-degree figure was in fact not the principal Paris goal, which was "well below 2 degrees". But the small island states in the Pacific, Caribbean and elsewhere which are most existentially threatened by climate change - some of the lowest-lying will not survive rising sea levels at all - have succeeded in making 1.5 degrees the new benchmark of success.

Remarkably, the conference didn't just accept the new goal. It also acknowledged that countries' current plans to reduce emissions would not get anywhere near meeting the goal, and they resolved to come back next year with stronger plans aimed at doing so.

On this criterion alone, COP26 should probably be regarded as a relative success. Given the pre-conference hype about Glasgow being "the last chance to save the planet," many in the public might have been forgiven for expecting that countries were going to announce new and stronger commitments during the conference. But that was never going to happen. Countries came to the meeting with emissions-reduction targets painfully decided - in most cases - in their domestic political systems. This is why the Paris Agreement calls them "nationally determined contributions", or NDCs. Countries had neither the desire nor the mandate to raise their ambition levels during this fortnight, and the possibility of doing so was not even on the agenda.

So the most this conference could ever have done was to acknowledge that the global reduction in emissions likely to be achieved by 2030 - when all the individual country's pledges are added up - was nowhere near enough to put the world on a path to limiting heating to 1.5 degrees; and to resolve to come back in a year's time with stronger commitments. This the conference did.

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The numbers presented were stark. Current national pledges up to 2030, if implemented, would lead to an average global heating of 2.4 degrees. At those temperatures the oceans would be stripped of all coral reefs, many land species would become extinct, major regions would lose their water supplies, and productive agriculture in many countries would become untenable. Revisiting and strengthening NDCs is crucial if the projected temperature rise is to be averted.

So now what? Attention will inevitably turn back to domestic politics. It will not be easy for any country, barring a few with very weak plans (such as Australia), to find ways of cutting their emissions further than they have already planned. New policies will be required, and new investment funding provided, whether in renewable energy sources such as wind and solar, regenerative agriculture or research and development into green technologies.

Can it be done? Technically and economically, yes. But politically, for many countries, it will be mighty hard. The Glasgow agreement acknowledges the need to support a "just transition" - the provision of alternative jobs and incomes for the workers and communities of high-carbon industries - but it will still be difficult to overcome the power of incumbent interests. The fossil-fuel sector will defend itself vigorously for a while longer.

And yet Glasgow did feel like a turning point. Never at a COP has there been such a recognition of the injustice faced by poorer countries because of a problem caused by rich ones. Never have leaders been confronted so directly with the evidence of their failure. Never have they admitted that failure, and agreed to have another go. India's pyrrhic victory in the dying minutes of the conference may have given heart to all those still wedded to coal. But to the rest of the world it looked like the beginning of the end for the age of fossil fuels.