Climate crisis: What Trump's environmental rollbacks mean for global warming

President has repealed or weakened at least 100 environmental regulations over past four years

Donald Trump has made dismantling federal climate policies a centrepiece of his administration.

A new analysis from the Rhodium Group finds those rollbacks add up to a lot more planet-warming emissions: 1.8 billion metric tons of greenhouse gases in the atmosphere by 2035. That’s more than the combined energy emissions of Britain, Germany and Canada in one year.

The Trump administration has acted to repeal or weaken at least 100 environmental regulations over the past four years, including Obama-era climate policies that Mr Trump has said stifle businesses. 

The rollbacks include:

Fuel economy standards

The Trump administration changed Obama-era rules that would have required new passenger cars, SUVs and pickup trucks sold in the US to become less polluting over time. Instead of improving fleet-wide fuel economy by 5 per cent annually for model years 2021 through 2026, automakers will now have to improve just 1.5 per cent per year.

California’s authority to set its own tailpipe emissions standards and to mandate electric vehicles was also revoked by the administration. The state’s special right to set stricter automobile pollution limits than the federal government’s dates back to the Clean Air Act of 1970 and for years the state has required that automakers sell a certain amount of electric vehicles.

As of September, 13 states and Washington, DC have formally adopted California’s policies and are challenging the administration’s decision in court.

Together, these vehicle rollbacks would have the largest effect on future emissions. New cars and trucks are expected to emit 1 billion more tons of carbon dioxide through 2035 than they would have if the cleaner vehicle rules had stayed in place.

The rule changes could also lead to 5 million fewer electric cars sold over that span, the Rhodium Group, a research and consulting firm, estimated. The transportation sector is the largest source of greenhouse gas emissions for the US.

Methane leaks from oil and gas operations

The Trump administration has also sought to revise or reverse two major Obama-era rules aimed at limiting leaks and intentional venting of methane, a powerful greenhouse gas. (In July, a federal judge blocked the rollback of one of these rules, concerning methane on public lands, but the administration is still pushing to repeal it.) 

Methane is the primary ingredient in natural gas, but when it escapes into the atmosphere before being burned for energy, it can warm the planet 36 times as much as carbon dioxide does over a 100-year period. Several recent studies have found that more methane is leaking from oil and gas facilities than previously thought.

Regulations on methane leaks from landfills, another significant source of emissions, were also delayed under Mr Trump.

Methane is created when food and other waste decomposes under low-oxygen conditions. The Obama administration had issued rules to capture more of this methane from waste. 

These potent greenhouse gases are used in air conditioners, refrigeration and insulating foams. In 2017, the world’s nations agreed to phase out HFCs in favour of alternatives less dangerous to the climate but the Trump administration has not ratified that treaty and instead has proposed to roll back federal regulations curbing the use of HFCs in the US.

Regulations on hydrofluorocarbons, or HFCs

Assuming these Trump administration policies go forward as planned and survive legal challenges, the US will emit the equivalent of an extra 1.8 billion tons of carbon dioxide between now and 2035, the Rhodium Group estimated. That’s more than Germany, Britain and Canada together emitted from energy use in 2018, the latest year for which data is available.

Greenhouse gas emissions are the main driver of global warming, which is increasingly causing damage throughout the US. More frequent flooding along the coasts, increased fire hazard in the West, worsening air quality, and fiercer heat waves have all been tied to rising global temperatures. If emissions are not reined in, scientists say, the damage will only deepen.

The new analysis looked at total emissions over the next 15 years because the impact of these rollbacks will grow over time, said Hannah Pitt, a senior analyst at the Rhodium Group.

New cars and trucks sold today are expected to stay on the road for more than a decade, for example, which means they will steadily emit more carbon dioxide than they otherwise would have under more stringent rules.

The rollbacks measured here represent only a portion of the climate policies that the Trump administration has sought to reverse.

Mr Trump has also moved to withdraw the US from the Paris climate change agreement, an international accord to reduce greenhouse gas emissions, and has pushed to open up new federal lands for oil and gas development.

The Energy Department also plans to change federal rules that would have required more efficient lightbulbs. But it is difficult to quantify the full effects of many of those policies, and they were not included in the Rhodium Group analysis.

Mr Trump has also repealed and replaced the Obama-era Clean Power Plan, which aimed to push states to reduce emissions from coal-fired power plants and shift to cleaner alternatives like natural gas or renewable energy.

It is unclear what effects this move will ultimately have: many states have been retiring coal plants and shifting to cleaner alternatives recently — because of the falling cost of natural gas, wind and solar power — and were already beating the targets set by the Obama-era rule.

The coronavirus pandemic has injected an extra dose of uncertainty into this analysis. As states locked down, transportation emissions fell as people drove fewer miles.

The Rhodium Group analysis assumes that US economic activity will largely recover in the years ahead, and there are already signs of a rebound. But if, for instance, vehicle traffic remains depressed for years to come, then the fuel-economy rollbacks will have a somewhat smaller effect on emissions.

The Trump administration’s rule changes have not halted all efforts to address climate change nationwide. Even as the federal government retreats from regulating emissions, many states and cities are acting on their own to clean up pollution from power plants and buildings.

California has struck an agreement with five large automakers — Ford, Honda, BMW, Volkswagen and Volvo — to stick to Obama-era fuel-economy standards, which will partly blunt the effect of Mr Trump’s rollbacks. States like Colorado and New Mexico are creating policies to curb methane leaks, and at least 16 states have announced plans to cut the use of HFCs.

Overall, planet-warming emissions in the US are expected to be lower at the end of Mr Trump’s first term than they were when he took office, in part because of action by states and cities. But the rollbacks mean that emissions will still be higher than they would have been if the rules had stayed in place, at a time when scientists and environmentalists say they will need to fall even faster to avert the worst consequences of global warming.

Perhaps the biggest uncertainty in gauging the climate effects of the Trump administration is the election. If, for instance, Joe Biden wins the White House and swiftly moves to reinstate new rules on vehicles, methane and HFCs — or puts in place even more sweeping policies to cut emissions, as he has pledged — the effect of Mr Trump’s changes could, in theory, be undone. If Mr Trump wins, however, many of the rollbacks are likely to stay in place.

New York Times