Donald Trump re-election would imperil climate action, leading scientist says

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One of the world’s leading climate scientists has warned that another Trump presidency in the US would imperil the chances of limiting the global temperature rise to 1.5C above pre-industrial levels.

Johan Rockström, co-chair of the Earth Commission and director of the Potsdam Institute for Climate Impact Research, said a Trump re-election would slow the pace of the shift to cleaner energy systems that is needed to curb climate change.

The former president withdrew the US from the Paris Agreement on climate change after his 2016 election, and his return to power would also likely result in other countries stalling on climate action, Rockström said. He also expressed concern about the future of the US’s landmark Inflation Reduction Act, which provides $369bn in green grants and subsidies.

“If Trump comes into power, there will be a destruction of the IRA and we will lose pace. It will mean that the signal to the world is, at best, another four years of pause on the action,” he said.

“We don’t have that time. We cannot wake up in 2030 and continue emitting as we do today because we know that the global carbon budget, to have any chance of holding 1.5C, is consumed over the next five years.”

Under the Paris Agreement, almost 200 countries have pledged to limit the long-term global temperature rise to 2C and ideally to 1.5C. Scientists have already warned the 1.5C limit is increasingly at risk of being breached, as countries fail to reduce greenhouse gas emissions.

In order to keep below 1.5C, global greenhouse gas emissions must be cut by almost half by 2030. Emissions have instead increased each year, except during the Covid-19 pandemic when lockdowns were in place.

In a televised debate with vice-president Kamala Harris on Tuesday, the final question “what would you do to fight climate change?” was ignored by Trump, who spoke instead about tariffs on imported cars, while Harris, his Democratic opponent, spoke about green investment under the Biden administration.

“I fear that with the wrong leadership in the US, that more countries may be stepping up and sitting on the fence in a wait-and-see mode and we don’t have time for wait and see,” Rockström said.

Research by 65 natural and social scientists from 20 countries, including Rockström, finds the Earth’s system is being pushed to its “safe and just” boundaries. The planet’s ability to provide and protect all the people was being pushed to its limits, it said.

The study, published in The Lancet Planetary Health on Thursday, is the first research to put a “floor” on the minimum needed for people to live a life free from poverty, using five metrics including climate, water, air quality, fertilisers and biodiversity.

The findings show that the poorest were already being hit hardest by changes, from climate change to water availability.

But it also warned that wealthier countries were becoming increasingly exposed. While India was among those countries most affected by water shortages, developed nations such as Germany were also affected.

A long-term rise in the global average temperature of 2C by the end of the century would see 30mn people in Bangladesh alone hit by sea level rises. The UK population would be among the most affected developed countries by sea level rise, with an estimated 6mn people exposed

The temperature increase in the industrial era is already at least 1.1C, according to UN scientists, and is projected to climb to 2.7C this century on the present emissions trajectory.

Rockström said at a 2C temperature rise, 2bn people would be exposed to so-called high wet-bulb temperatures, where humidity levels coupled with air temperature make it difficult for the human body to cool.

Joyeeta Gupta, former co-chair of the Earth Commission and a professor at the University of Amsterdam, said the effect on human life would probably be more in the global south but wealthier countries would also suffer.

“The impacts in terms of finances, infrastructures will also be in the global north. And once we pass 1.5C, for example, once we pass the tipping points, there will be huge damage everywhere.”