The writer, a former head of the downing street policy unit, is a harvard senior fellow

Standing in a charred forest, his voice hoarse, california governor gavin newsom promised to accelerate his states move to 100 per cent renewable energy. were experiencing what so many predicted decades ago, he said bleakly. that is now reality.

It is getting harder to look away from the wildfires burning across the american west, record floods in pakistan or the melting of greenlands biggest ice shelf. record temperatures have become a pattern globally. in greece, south korea, mexico, japan, france and spain more than three-quarters of citizens surveyed now believe that climate change represents a major threat to their nations. yet in much of the world, that strength of feeling is rare.

As a threat to the planet, human health and livelihoods, tackling extreme weather should be as obvious an imperative as handling the coronavirus pandemic. but this complex issue is not such a visibly immediate challenge and, fatally, it has been made political.

Twenty-five years ago, climate change was not an especially partisan issue in the us. in 1997, about half of both democrat and republican voters told pollsters they agreed that the effects of global warming had already begun. a decade later, there was a 22 percentage point gap: 70 per cent of democrats said the effects had already begun, but republicans hadnt budged.

Today, only 39 per cent of republicans and independent voters who lean right think environmental issues should be a priority for the us president and congress, compared to 85 per cent of democrats and left-leaning independents. and intriguingly, if youre a democrat, knowledge and understanding of science is highly correlated with a belief that human activity contributes to climate change, but it makes almost no difference if youre a republican, according to pew research.

It makes no sense that one group of voters should care less about conserving nature and protecting their homes than another. yet in the uk, people who voted for brexit are much less likely to agree that climate change is definitely happening than those who voted to remain in the eu.

The painful irony for climate campaigners on the progressive left is that environmentalism has come to be seen as synonymous with being anti-business, playing into the hands of deniers.

Us president donald trump was almost wholly wrong when he tweeted in 2012 that the concept of global warming was created by and for the chinese in order to make us manufacturing non-competitive. but he was also just a tiny bit right: china has long used calls for climate justice to demand concessions to help it industrialise.

This week, some british environmentalists responded to the news that hitachi is abandoning plans to build a welsh nuclear power plant with delight. new nuclear power is not the answer in the climate emergency, one tweeted.

Really? the sage environmentalist james lovelock has long argued for nuclear power. in germany, green pressure to close nuclear has led to more coal burning.

But such prosaic considerations dont suit nihilist tendencies. just when there might be a real chance to make headway, given the alarming headlines around the world, parts of the green movement seem to have slipped back into adolescence.

Extinction rebellion, which gained such positive momentum last year, is starting to look more like a lunatic fringe group. blockading uk newspaper printing sites while tweeting the government is an #etonmess that is out of touch with the people taints the green movement with a nasty streak of class war and authoritarianism. if we want to persuade people to junk their cars, give up eating meat and pay higher heating bills, its not advisable to tell them they are idiots who should be censored.

At least the xr activists i have met live green lifestyles, unlike the learjet liberals. for these chattering classes who fly to earnest climate change summits, the inconvenient truth touted by former us vice-president and climate campaigner al gore is especially inconvenient. this hypocrisy makes it harder to solve an issue that is above all a free-rider problem: why should i make sacrifices if you dont?

It is time to change the argument. multilateral agreements, while heroic, have largely failed. governments have competed to protect their economies and have not been able to move too far ahead of public opinion. yet, for many countries, climate change is a matter of national security.

Weather changes that wipe out crops hurt farmers; wars over water bring desperate refugees to foreign shores; warming oceans will put some nations underwater; and reliance on fossil fuels means being beholden to some unpleasant regimes.

It is also a matter of prosperity. hence in the us many red states have green laws: texas is a world pioneer in wind energy. iowa, kansas and oklahoma lead the country in renewable energy production. mr trump should realise that the race for clean energy will be won by china, if he keeps repealing legislation.

This year, california has lost an area almost as big as connecticut to flames. governor newsom can act against a backdrop of such visible destruction. if the rest of us dont, we are truly playing with fire.