Minnesota has cut its greenhouse gas emissions steadily in recent years as electric utilities around the state gave up coal to fire their generators.

But the state still lags a set of long-term climate change goals it set for itself in 2007 — and that's largely because of car and truck traffic.

For the first time, vehicles are producing more of the heat-trapping pollutants than power plants, according to a new report by the Minnesota Pollution Control Agency (MPCA). While transportation emissions have fallen since 2005, they haven't dropped as much as hoped, said Todd Biewen, director of the MPCA's environmental analysis and outcomes division.

"Because of the low cost of gasoline, because people are driving larger vehicles and really are not cutting back on their mileage we haven't seen some of that progress," Biewen said.

Emissions from vehicles were down 8 percent from 2005, but remained virtually flat between 2015 and 2016, the report shows. The agency's latest data are from 2016 because it takes the state about two years to compile and analyze emissions across various sectors of the economy. The agency prepares the report every two years, at the Legislature's direction.

It's unclear how much, if any, progress has been made since 2016, because gas prices have remained low and electric cars and charging stations are still in their infancy.

Overall, greenhouse gas emissions in Minnesota fell 12 percent between 2005 and 2016 — short of the Legislature's goal to reduce them 15 percent by 2015. The 2007 legislation, the Next Generation Energy Act, also promised to cut emissions 30 percent by 2025 and 80 percent by 2050.

While still below the target, a promising sign is that Minnesota has managed to cut emissions even as its population and gross domestic product have climbed by 8 and 12 percent respectively, Biewen said.

"That shows intensity is down significantly," he said. "We can reduce emissions in a healthy expanding economy."

The biggest reductions have come from Minnesota's power plants, which, historically, have been the state's largest greenhouse gas producers.

With power companies shuttering more and more coal plants in favor of wind, solar and natural gas, emissions from the utilities fell by nearly 30 percent from 2005 to 2016. Natural gas prices have remained low since then, and eight more coal plants are scheduled to close over the next three years, suggesting that those numbers could continue to fall, according to the report.

Consumer demand for renewable energy and a sharp drop in the cost of setting up solar panels and wind farms are two major factors driving the trend, according to Gregg Mast, executive director of Clean Energy Economy MN.

"Wind and solar costs have been declining by about 70 and 90 percent in the last 10 years," he said.

Xcel Energy, the state's largest electricity provider, announced last month that it plans to be completely carbon-free by 2050.

"That's a really big deal," said J. Drake Hamilton, science policy director of Fresh Energy, a nonprofit based in St. Paul. "No other utility in the nation has matched that."

It shows that utilities have come to believe that clean power makes business sense, Hamilton said.

The question is how to replicate that success with vehicles, she said.

The MPCA report does address that challenge. Many advocates hope that carmakers will develop more efficient engines and eventually switch out the internal combustion engine to go electric. But the effort is unlikely to get much help from Washington, D.C., as the Trump administration has proposed rolling back Obama-era vehicle emission requirements.

The MPCA has proposed using up to 15 percent of the state's $47 million share of settlement money from a lawsuit against Volkswagen, which was caught programming its cars to cheat emissions tests, to install charging stations for electric vehicles around the state.

Mostly, Minnesota should beef up its electric vehicle infrastructure, set its own vehicle emission requirements, or use some combination of the two, Hamilton said, if it hopes to meet its targets.

More than two dozen businesses, including some of the largest employers and energy consumers in the state, have formed a coalition that is calling for the state to surpass its long-term goals.

"There is a strong business case for going above and beyond those goals," said Amy Fredregill, managing director of the Minnesota Sustainable Growth Coalition, a business-led group that includes 3M, Cargill, General Mills and a handful of the state's Fortune 500 companies.

"We know that reducing emissions would create new kinds of jobs and reduce costs and risks," Fredregill said. "But if Minnesota can be the leader in this, the region really could be branded for sustainability, which would be good for companies here."