When it looked like the news couldn’t get any worse, it did: worse in a way that dwarfed our petty elections and clueless, pendulum analyses, worse in a way that dusted the present with the irrelevance of history. In the journal Science Advances, five of the world’s most eminent climatologists warned of the possibility that warming may be significantly worse than we thought. Previous consensus was that the Earth’s average temperature would go up by between 2.6C - life-altering but manageable - and 4.8C - cataclysmic. Now, the range suggested by one projection goes up to 7.4C, which is “game over” by the 22nd century.

It relates to the US because their incoming president has promised actively, determinedly to bring about the worst-case scenario, acting on the now familiar, pre-enlightenment logic that because it’s beyond the limits of his intellect to comprehend it, climate change doesn’t exist. But it relates to, or rather clarifies, things on a deeper level.

Rational American citizens are, post-Trump, going through the same grief trajectory as many of us did after Brexit: the debate is all fierce conjecture about how they lost, whom they failed to listen to, whose anger had been ignored and by which people for how many decades. But underneath that is a profound crisis of civic engagement – a deep, agonising question: what is the point? If reason doesn’t matter, if truth doesn’t, if solidarity is for wimps, if experts are charlatans, what’s the point of getting involved in this circus?

Paul Krugman identifies it as a creed of quietism, conceding: “It’s definitely tempting to conclude that the world is going to hell, but that there’s nothing you can do about it, so why not just make your own garden grow?” Ultimately, he chooses engagement to save the soul: “I don’t see how you can hang on to your own self-respect unless you’re willing to stand up for the truth.” The American journalist Nancy LeTourneau took it one step further and tried to find a positive in the powerlessness, via Gandhi: “Whatever you do in life will be insignificant, but it’s very important that you do it.”

Patriotism, self-respect, for the sake of your neighbours, for the good of your children: these are all credible and decent reasons to carry on fighting the hard right even when it knocks over your strongest arguments with a casual breath. But the urgency of the climate crisis is a better one. Authoritarians, “strongmen”, fascists: whatever you call the figureheads of the new right, you know one thing; they are never good stewards of the Earth. To accept this political order as a desperately sad but immovable new normal means accepting that the Earth will burn and there’s nothing we can do. This cannot be borne.

In practical terms, this means picking winnable fights, showing solidarity, and being visible. I can’t do very much about a country not my own and its adherence to the Paris treaty, but I can join a 10:10 action on the UK government’s stance on wind energy. You can’t do very much about oil exploration in Alaska, but you possibly can do something about keeping the gas in the rocks of the Ribble Valley. Capitalise on victory: there is no more buoying story I can think of than that the Balcolmbe fracking protest turned into a green-lit solar farm. When the world gets its first solar-powered transport network (Santiago), when a country runs for four days entirely on renewables (Portugal), celebrate. If there’s a synchronised global march for the climate, go to it: there has always been a tendency to write mass environmental protests off as self-indulgence, pointless by definition because their participants will go back the very next day to their fossil-fuelled lives. Intolerance of imperfection is fatally corrosive to any movement, but to environmentalism most of all. It is not possible to be perfectly green, yet you can be a vivid green by turning up.

This has been the year the liberals lost every argument. Explanations range from “they lost because they were wrong all along” to “the right always prospers from economic hardship”, but there is a growing consensus around one thing. We remain quite good at interpreting data, pointing out incoherence, making sarcastic remarks. But we lost the ability to make a bold, ambitious, sincere and plausible case for a better future, settling instead for a future that wasn’t worse. This has been the case across Europe and the US. It cannot be blamed on British politicians, singly or en masse. Its global scope has led many to look for the cause in global trends: financialisation, corporate greed – things that, for brevity, we class as neoliberalism.

Optimism accrues around each hopeful action, each small victory, until it becomes obvious that it is the driving force

I wonder whether the answer is something much simpler: we stopped making the case for hope when we stopped feeling hopeful. The spectre of climate change, much more influential on the left than on even the sensible right, loomed so large that we - reasonably enough - began to fear the future, at the same time losing confidence in our collective ability to do anything but mess stuff up. The pessimism infected our political language, left it pale and limp. But it didn’t actually halt progress: discoveries were made and solutions found. We have, in likelihood, the technical expertise to halt emissions forever. Between electric cars and solar glass, between wind power and cross-continental supergrids, we have amassed enough sheer ingenuity to fix the unfixable. The only obstacle – granted, it’s a significant one – is a post-truth politics that would prefer to pretend there’s nothing to fix.

Optimism is not something you can decide to rediscover; nor can you fake it with rhetoric. It’s not something one really good leader can bestow. It accrues around each hopeful action, each small victory, until it becomes obvious that it is the driving force.

Many of us frame our interest in the environment as a care for our children or grandchildren, as if a visceral love of nature had to have a self-interested root to make sense. It doesn’t. Senselessness would be to try to live and find meaning elsewhere, having put the preciousness of our habitat to one side.