The world will be watching the US presidential election on Tuesday 3 November, but just 24 hours later is another hugely consequential news event when the US will formally leave the Paris climate agreement.
The Trump administration set the withdrawal in motion with a letter to the UN, and, in a coincidence of timing, the US will exit the day after the election, joining Iran and Turkey as the only major countries not to participate in the agreement.
What is the Paris climate agreement?
After decades of negotiations, all 197 nations in the world agreed to voluntarily cut the heat-trapping pollution that is causing the climate crisis. Only a handful have not ratified the deal.
It is seen by many as the minimum effort the world needs to make on cutting emissions – but it still took a monumental diplomatic push to clinch the deal.
It came together in Paris in 2015, under the United Nations Framework Convention on Climate Change. The US negotiating team – including the then secretary of state, John Kerry – scrambled to try to Republican-proof the agreement.
President Obama, who was part of 11th-hour efforts calling round other world leaders to join, said in his address “we met the moment”, called it a turning point, while acknowledging more would need to be done.
The agreement’s official goal is to keep the world from becoming 2C hotter than before industrialization. But its ambition is to limit heating to 1.5C, a best-case-scenario scientists see slipping out of reach.
Each country agreed to set its own targets and report back on progress.
So is the agreement working?
There have been some achievements in cutting emissions but the work countries have done so far is not enough to limit the temperature rise to 2C. The world is already about 1C hotter than the pre-industrial period.
Despite the Paris agreement, it is on track to become around 3C hotter. Already, humans are suffering from what they have done to disrupt the climate. And yet more heating will trigger more intense heatwaves, faster sea-level rise that will flood major cities, and more extreme weather disasters that will strain government responses.
What will happen if Donald Trump is re-elected?
Trump held a news conference in the White House’s Rose Garden in June 2017 when he vowed to exit the agreement, saying it was unfair to the US, which would leave and then start negotiations to re-enter it or a new accord “on terms that are fair to the United States”.
“I was elected to represent the citizens of Pittsburgh, not Paris,” he said (the mayor of Pittsburgh responded by saying the city stood with Paris).
Trump, though, could not immediately leave the agreement – he can do so only after the November election, in a quirk of timing.
So on 4 November 2019, the US began the year-long process to pull out of the deal, sending the United Nations notification that it would formally withdraw on 4 November 2020.
What will the world look like if humankind fails, and heating soars beyond 2C?
In just a 2C hotter world, according to an analysis of 70 peer-reviewed studies by Carbon Brief:
Seas could rise an average of 56cm, or nearly 2ft.
30m people in coastal areas could be flooded each year by 2055.
Thirty-seven per cent of the population could face a severe heatwave at least every five years.
388m people could be exposed to water scarcity and 195m will be exposed to severe drought.
Maize crop yields could fall 9% by 2100.
The global per-capita GDP could fall 13% by 2100.
Has Trump’s administration tried to tackle the climate crisis?
The short answer is: no.
During the last four years, Trump’s administration has undermined international climate efforts by aggressively supporting fossil fuels. Domestically, Trump has rescinded or weakened essentially all the major regulations that were meant to encourage a shift away from oil, gas and coal, and toward cleaner sources of energy. He has eliminated Obama-era rules requiring lower-carbon electricity and cars. He has expanded opportunities for drilling and mining.
What will happen if Trump wins re-election?
With another four years as president, Trump could lock in those changes, further delaying action at a time when scientists say it is urgently needed.
The US promised to cut emissions 26% to 28% below 2005 levels by 2025. The reductions were meant to be just the beginning of US efforts.
Depending on how deeply the economy is hit by the Covid-19 pandemic, the US could see its emissions drop between 20% and 27% below 2005 levels by 2025, according to an analysis by the economic firm Rhodium Group. While the US could technically achieve what it pledged, those reductions are not nearly enough to stall significant global heating. If every country made efforts on par with the US goals, the world would still get 3C or 4C hotter, according to independent analysis by the Climate Action Tracker.
Even without the US government, the power sector has shifted away from coal and toward cheaper natural gas and renewable energy – contributing to the drop. But reductions beyond what Rhodium projects would probably require new rules and incentives from the government.
What would happen if Joe Biden is elected?
Biden would immediately move to rejoin the Paris agreement, which would take about 30 days. The former vice-president has outlined an ambitious climate plan, but most of it requires sign-off from Congress. His proposal will be nearly impossible to implement if Democrats do not take control of the Senate. Significant climate legislation will be difficult to pass even if Democrats do have a majority in the House and the Senate and Biden is in the White House.
Biden has said he would set in motion plans to cut US emissions to net-zero by 2050 – which is on par with what scientists say every nation in the world needs to do to avoid the worst of the climate crisis.
He wants the electricity system to be carbon-free by 2035. He says he would invest $2tn on clean energy infrastructure and other climate measures, spending as much as possible in his first four years in office. The presumed Democratic nominee would decarbonize buildings, invest in high-speed rail and try to make the US the top producer of electric vehicles.
What’s at stake for the world if the US leaves?
If Donald Trump is re-elected and the US remains outside the Paris agreement, other nations might be less likely to pursue aggressive climate actions. The US is the biggest historical contributor to climate change, even though it holds just 4% of the world’s population.
China is the biggest current emitter. It is dramatically slowing its domestic emissions growth, although it is also funding new coal plants in developing countries.
With the US out of the picture, China could have more geopolitical influence, including in climate negotiations. It could also benefit greatly from clean energy manufacturing, particularly if the US continues to fall behind.
Even if the US national government is not active in climate efforts, green-minded US states and localities would likely come together to continue to pledge action to the world.