BLOWING hot and cold doesn’t begin to cover it. In 2009 Donald Trump signed a public letter calling for cuts to America’s greenhouse-gas emissions. In 2012 he dismissed climate change as a hoax cooked up by the Chinese. On the campaign trail he promised to withdraw from an international accord, struck last year in Paris, to fight global warming. This week, as president-elect, Mr Trump said he has an “open mind” on the Paris deal and that there is “some connectivity” between human activity and climate change. 

Such fickleness gives succour to pessimists and optimists alike. Those who are gloomy about the climate still expect America to ignore or withdraw from the Paris agreement, or to abandon the 1992 UN framework that underpins it. Sunnier folk hope that Mr Trump will govern differently from how he campaigned, enabling the fight against climate change to continue unabated. The reality is more complex. Mr Trump’s brand of “America First” populism will do nothing to help the planet, but neither need it be the catastrophe many fear.

Hot air
First, the bad news. Even if Mr Trump honours America’s commitment to the Paris accord, it is unlikely that his administration will galvanise action. Many in the Republican establishment think that climate deals are examples of global regulatory over-reach. Plenty of Mr Trump’s voters dismiss climate change itself as a phoney fad peddled by “bicoastal elites”. Fossil fuels stand for prosperity and freedom—from the romance of the roughneck to the lure of the road.

Sure enough, on November 21st Mr Trump pledged that on day one of his administration he would scrap “job-killing restrictions” on the production of American fossil fuels, which account for 80% of America’s man-made greenhouse-gas emissions.

The rhetoric is not the only thing that will be markedly different. The main practical way a Trump administration is likely to weaken the Paris agreement is by avoiding America’s commitments to pay large sums to help other countries cope with climate change. The burden of fighting global warming falls less on rich countries, where energy demand is stagnant and efficiency is rising, than on poor ones, where billions still lack the cheap energy fossil fuels can provide. Poor countries were won over partly by the $100bn a year that America and others promised to help them cope. Private investors were always going to have to stump up lots of cash to fund climate-change action; the onus on them will be heavier.

This is worrying. But, on close inspection, the path to a greener future still remains open, both in America and abroad. At home there are limits to what Mr Trump’s embrace of fossil fuels can achieve. For all the trillions of dollars-worth of oil and gas that he hopes will be fracked on federal lands, no one will sink a well unless it is profitable to do so. That needs oil prices to be substantially higher than they are now. Coal, too, has been displaced by cheap shale gas rather than Barack Obama’s regulations. Even if the new administration abandons America’s Paris pledges, California has its own clean-energy mandate and will continue to set fuel-efficiency standards that other states and the car industry follow. Besides, energy investments last for decades—firms may well be loth to bet that future presidents will stick with Mr Trump’s policies.

Nor need the fight against climate change elsewhere founder in the absence of American leadership. Self-interest will see to that. China takes air pollution in its cities at least as seriously as it does climate change—a recent study found that air pollution contributed to the deaths of 1.6m people in China each year. Switching from burning coal to cleaner forms of energy thus makes sense twice over. India needs climate action as insurance against extreme weather: it spends a fortune in the wake of storms, floods and other events.

Commercial self-interest will also keep other countries on the path towards decarbonisation.

The costs of clean energy are tumbling. The cost of batteries in electric vehicles has fallen by 80% since 2008; the bill for offshore-wind energy has more than halved over the past three years in northern Europe. Solar power is closing in on gas and coal as an attractively cheap source of power. China plans to have nearly 150 gigawatts of installed solar capacity by the end of the decade, triple what it has today as the world’s biggest solar generator.

As this week’s special report points out, such developments will curb demand for oil and coal in decades to come. Last year was the first in which renewable energy surpassed coal as the world’s biggest source of power-generating capacity (although natural gas will remain an important complement to renewables because of the vagaries of sun and wind). These are epochal changes, with moneymaking opportunities to match. China, for instance, hopes to become a clean-energy superpower by producing cheaper panels, turbines, batteries and electric cars, as well as the systems that link them all together.

Don’t COP out
To be clear, there is much to regret in the prospect of America relinquishing its leadership on fighting climate change. The idea of the world’s second-biggest polluter free-riding on the efforts of others has some countries mulling counter-attacks—one proposal, a carbon tariff on American exports, could lead to a damaging trade war. The Paris agreement was always likely to fall far short of its goal of limiting global warming to within 2°C of pre-industrial temperatures. A more recalcitrant America puts the prospect of deep decarbonisation even further off. And evidence that Mr Trump’s America is withdrawing from its global role is worrying.

Yet with climate change, as with other areas that have come to depend on American leadership, the rest of the world can make the best of a bad situation by staying the course. China’s carbon emissions may already have peaked. Improvements in cars’ fuel efficiency cut oil consumption by 2.3m barrels a day in 2015, even when petrol was cheap. China, India, the European Union, Canada and others have strong incentives to embrace cleaner technologies. If they work together they can make a difference—with or without the United States.