President Trump announced on Thursday that the US would leave the Paris Agreement, the landmark accord on climate that unites nearly every country with the goal of keeping the planet from warming by more than 1.5 Celsius (2.7 degrees Fahrenheit) above preindustrial levels.
There will most likely be several consequences not only for the climate but also for the US economy and jobs.
According to John Sterman, a professor at the MIT Sloan School of Management and senior adviser at Climate Interactive, leaving the Paris Agreement will create uncertainty in the economy about the future of fossil fuels and renewable-energy resources. That would be "bad for businesses" and others hoping to invest in renewable energy, and it could spread to other countries' economies. It would also lead to slower deployments of renewable energy, Sterman said.
The costs of these energy sources are decreasing, but with the US's exit of the Paris Agreement, uncertainty could cause solar and wind to be deployed more slowly, keeping their costs higher for longer and ultimately slowing the US's transition to renewable energy.
Another repercussion, Sterman says, is potential retaliation from other countries, which could also leave the Paris Agreement or punish the US in some way.
"It's not that far-fetched to imagine a scenario where China, in response to the US pulling out ... implements a carbon tax on all goods exported from the US to China, and others nations could follow suit," Sterman said.
This prospect reportedly led several fossil-fuel companies, including ExxonMobil and the coal-mining group Cloud Peak Energy, to urge the president to stay in the agreement. Sterman said coal, gas, and oil companies knew that while they may be restricted slightly by the Paris Agreement, they could lose their seat at the international negotiating table — with China, India, the European Union, and other world powers — if the US pulled out of the accord.
"By remaining in the Paris Agreement, albeit with a much different pledge on emissions, you can help shape a more rational international approach to climate policy," Cloud Peak CEO Colin Marshall said in a letter to Trump on April 6. "Without US leadership, the failed international policies that have characterized the past 25 years will continue to predominate. ... Addressing climate concerns need not be a choice between prosperity or environment."
There are also likely to be consequences for American jobs.
Trump made job creation a focus of his campaign promises, but, according to Sterman, ceding climate-action leadership to China would "cost jobs in the United States." Several jobs in producing wind turbines and solar panels have already been lost to China, but the US would lose more if it pulled out, he said.
Sterman said the US would lose jobs that could only be done locally, like installing, operating, and maintaining solar panels and wind turbines. These kinds of jobs mostly are occupied by blue-collar workers, who are "the base of President Trump's support," Sterman said.
Scott Pruitt, the administrator of the Environmental Protection Agency, and Steve Bannon, the White House's chief strategist, backed Trump's proposal to leave the Paris Agreement. But several news outlets reported that Trump's daughter Ivanka and his son-in-law and senior adviser, Jared Kushner, supported staying in the accord.
Below is a map of countries that have signed or ratified the Paris Agreement. The US now joins Syria and Nicaragua as countries that aren't members of the agreement. Syria, in the midst of a civil war, did not participate in the agreement's signing. Nicaragua said it did not sign the agreement because it didn't go far enough.