A near record number of U.S. coal plants shut down in 2018. Carbon emissions still made a huge jump, report says.

A near record number of coal plants shut down last year, and the U.S. still emitted 3.4 percent more carbon in 2018 than the year before, according to a preliminary estimate.

That’s the second-largest increase in 20 years, fueled in large part by a booming economy that caused people to travel more and manufacturing to surge, according to economic research firm the Rhodium Group, which released the report Tuesday. Only in 2010, as the country rebounded from the Great Recession, did emissions increase more than they did last year.

As the Trump administration rolls back climate and environmental regulations, the report illustrates the extent to which even those policies weren’t sufficient: The authors argue that regulators will have to target new sectors of the economy if they hope to reduce emissions substantially.

Back in 2014, the U.S. pledged to reduce its carbon emissions 26–28 percent lower than 2005 levels by 2025. The country now stands farther from achieving that goal than it did a year ago.

The biggest emitter, according to the report, was the transportation sector, which took the title for the third year running.

Within that sector, the use of diesel and jet fuel from planes and trucks also played a large role and contributed to a 1 percent increase in that sector — even as gasoline use dropped. Environmental regulators have largely focused their efforts on tailpipe emissions, which the Trump administration has sought to roll back.

Domestic manufacturing also boomed last year, posting year-over-year emissions increases of 5.7 percent and sending up 55 million metric tons more carbon than in 2017. Regulators haven’t focused on limiting emissions from that sector, and the report’s authors estimate that industrial emissions will become second leading source of emissions in California by 2020 and the leading source of emissions in Texas by 2022.

Despite the jump last year, the U.S. has reduced emissions over the last decades mostly by swapping coal for natural gas. In 2018, for example, coal plants closed at twice the rate that they did the year prior, accord to a report from S&P Global.

As a result, the U.S. has reduced emissions by a modest average of 1.2 percent per year between 2005 and 2017, according to the new report.

Regulators have emphasized the switch to natural gas in the last decade because, although it’s still a fossil fuel, it emits less CO2 than coal when burned. (Natural gas production, however, leaks a ton of methane, which can trap as much as 80 times more heat in the atmosphere than carbon dioxide.)

In addition to economic growth, a colder winter in 2018 than in 2017 also fueled some of the year-over-year in carbon emissions (although 2018’s winter was still warmer than average). In places like New England, people used more energy to heat their homes than they did the year before. With less coal capacity, natural gas and oil picked up the slack.

The U.S. isn’t alone in failing to reduce its emissions. During a year when the seriousness of the climate threat became clearer than ever, emissions around the world hit an all-time high in 2018.

Cover image: Traffic was jammed for a time for miles in both directions on the Hollywood Freeway, also known as U.S. Highway 101. (AP Photo/Damian Dovarganes)