The sharp rise in carbon emissions in the United States in 2018 is partly due to the economic growth the country experienced last year, experts say. But the economy was growing throughout the previous three years, when carbon emissions fell—so why have emissions gone up now?
According to Nate Aden, a senior fellow with the World Resources Institute’s climate program, economic growth was always going to result in a year-over-year increase in emissions eventually because of the way the US’s energy and manufacturing systems are set up—which is to say, not to the climate’s benefit.
“The challenge is just that there are bumps in the road and the structure of the economy makes a big difference,” Aden said in a phone interview. “Basically, we’re firing on all cylinders, particularly in industry.”
Aden said that the American economy has been gradually on the rise ever since the 2008 crash. At first, a lot of that growth came from sectors that don’t produce a ton of emissions—think service industries—so the economy’s upturn wasn’t hurting our reduction in carbon emissions.
But in the last few years, and in particular in 2018, a lot of the growth has occurred in America’s industrial sectors. The way these industries function is to idle or shut down older, less efficient plants when the market isn’t doing well. Once demand starts to return, those old, polluting factories start to get reopened, causing a spike in emissions, Aden said—a trend we saw throughout 2017 and 2018.
“Let’s say, for example, pulp and paper manufacturing: we’ve got mills in the US that are from the 19th century that are still used and when demand goes down, those facilities get mothballed,” Aden said. “But then in times like last year, when demand is up and there’s a market for those products, then it makes sense for those companies to bring those facilities back online.”
However, this isn’t an inevitable outcome of economic growth itself, but rather US policies, as other countries around the world continue to demonstrate. Many European countries, such as Sweden and Hungary, continue to decrease their annual greenhouse gas emissions while also enjoying robust economic growth. The balance comes from transforming the dirtiest sectors by providing incentives and regulations that encourage companies to invest in new, cleaner technology and retraining workers—something the US has been slow to adopt.
Meanwhile, America’s investment in natural gas and oil fracking has continued to increase. Indeed, US crude oil production hit a record milestone in 2018, according to the US Energy Information Administration. While this originally helped to reduce our overall carbon emissions because it was replacing coal, Aden said, we’ve reached the limit of the benefits of replacing one greenhouse gas with a slightly more efficient greenhouse gas.
Still, Aden said the increase in emissions last year doesn’t necessarily predict a dreadful trend. Though President Donald Trump’s administration has slowed, or straight-up cancelled, many efforts to balance out economic growth with our climate goals, state governments and even the private sector have been moving in the right direction, Aden said.
“US emissions peaked in 2007 and we’re still more than 10 percent below that peak,” Aden said. “While [2018’s increase] is clearly a step in the wrong direction, I don’t see this is as a reversal of that long-term trend. The broader move towards more efficiency and renewable energy is, I think, going to be sustained regardless of what folks in Washington decide to do.”