Boris Johnson is a lucky politician.  He wouldn’t be Prime Minister today if he wasn’t, though luck is sometimes made as well as had.  But he is out of luck at COP26.  And not just because of the disruption on the West Coast main line, or because the Queen isn’t able to attend in person.

The summit opened with Emmanuel Macron apparently bent on waging a warmish war over fishing as well as a coldish one over the Northern Ireland Protocol.  Xi Jiping is not in Glasgow, and has no reason to do Johnson any favours, now that the shine has come off the Cameron-era “golden age” of Anglo-Chinese relations.

Narendra Modi is there – but has declared that India won’t aim to reach Net Zero until 2070.  Vladimir Putin, another man with no reason to help pull Johnson’s irons out of the fire, isn’t in Glasgow either.  So he is unavailable to be quizzed about how his recent proclamation of a 2050 Net Zero target is compatible with Russia’s plan to increase gas production by 50 per cent by 2035.

This is the nub of the matter.  The main point of COP26 is to deliver on COP21 – i.e: the Paris Agreement.  Or, in short, to move from talk to action when it comes to keeping the global temperature from exceeding 1.5°C above pre-industrial levels”.  Since China, India and Russia are three of the world’s four biggest carbon emitters, delivering on Paris was always going to be what civil servants call “challenging”.

The Prime Minister’s priorities for the summit are “coal, cars, cash and trees”.  He has got the pledge he wanted on trees – to end deforestation by 2030 – though it may well not be honoured, given the demand for palm oil, soy and beef, and the history of similar commitments.  He won’t get it on coal.

In sum, it would be surprising were the mass ranks of sherpas, working parties and politicians not to produce an agreement.  But given the gap between what the COPs are meant to achieve and what COP26 is likely to, I can’t help wondering if it will come to be seen as the beginning of the end of them.  They will stagger on but such momentum as they have is being sucked out of them.

How much damage would failure in Glasgow do to Johnson?  The extreme end of the green movement will always denounce anything that mainstream politicians say about the environment, whether the announcements they make are meaningful or not.  A larger mass of the British people hadn’t registered COP26 at all last year.  Despite the ceiling-to-floor media coverage, some still won’t have done.

Politicos poll of polls currently shows the Conservatives with a three per cent lead over Labour, and there’s no reason to think that disappointment at COP26 will have much effect on it, if any.  Panning the camera out more broadly, how much difference would failure make to public attitudes and Government policy?

On the former, your guess is as good as mine, if not better.  Perhaps a larger slice of the public will what the point is of reducing our minnow share of emissions if the giants carry on increasing theirs.  But the most likely outcome is the most predictable: that a minority of voters give the green project strong support, and a larger number weaker backing – until or unless their living standards are squeezed.

Our own surveys suggest that only one in ten Party members believe that global warming isn’t happening, though about a third think human activity isn’t driving it.  If the polling which Gabriel Milland described on this site yesterday is right, the proportion of Conservative voters believing both is smaller.

All in all, COP26 failure would make little difference to Government policy, if any.  Decarbonisation will continue, as it should.  Tory backbenchers will chase green subsidies for their constituents.  Ministers will nervously inch nearer carbon taxes.   But if and when they come under sustained pressure from voters, they will back off: for example, we’re unlikely to see a rise in fuel duty any time soon.

Perhaps carbon capture will finally deliver, or hydrogen will come rushing to the rescue.  Or human ingenuity will deliver Net Zero on time with technologies now undreamed of.  But the odds are that, given the choice between hitting targets and enraging voters, governments will choose to miss the former, and proclaim general success in reducing emissions amidst specific failure.

How much difference would failure in Glasgow – and “a rise in global temperatures above 1.5°C above pre-industrial levels” – make to the future of our planet?  The cheery view is that human beings are astonishingly adaptable and would adapt successfully.  Which provokes a gloomy question: how many and where, if nations fight for scarcer water and refugees flee desertifying land?

Few conservatives pondered these questions, and others, more creatively than Roger Scruton – especially in his Green Philosophy.  There are few better ways to end than by quoting a great conservative and environmentalist. “The greenhouse effect has been known for over a century and a half, and implies that, other things being equal, the accelerating production of carbon dioxide will cause the earth to warm.”

“But will other things be equal? That is where the disagreements begin….greenhouse gas emissions are only one factor in altering the balance of incoming and outgoing radiation on which the earth’s temperature depends. And among other relevant factors there are some for which the science is incomplete or in its infancy.”