The good news is, greenhouse gas emissions have seen declines in Minnesota, even as the state’s adding people and its economy is growing.

The bad news is, the state isn’t meeting the goals it set more than a decade ago to reduce release of these gases, which trap heat in the earth’s atmosphere like a blanket and warm the planet, according to a report released this month by the Minnesota Pollution Control Agency.

That’s despite the fact that emissions from electricity generation — once the biggest greenhouse gas emitting industry — have dropped markedly as the state has turned away from coal and toward less polluting power sources.

But as Minnesota looks toward its future, reducing greenhouse emissions significantly will require tackling what’s now the biggest cause of greenhouse gas pollution: transportation.

Not meeting goals

As part of a bipartisan effort under Gov. Tim Pawlenty, Minnesota passed the 2007 Next Generation Energy Act, set specific goals to cut emissions of greenhouse gases like carbon dioxide, nitrous oxide and methane that build up in the atmosphere — by 15 percent between 2005 and 2015.

The state hasn’t lived up to the aspirations it set then. In 2016, the most recent year of data available, it had only cut emissions by 12 percent from the 2005 baseline, 3 percentage points behind its goal for 2015.

Much of the reduction that did happen came from a dramatic drop in greenhouse pollutants from the electricity generation industry.

Around the time the Next Generation Energy Act was passed, the main reason electricity generation was pushing so much greenhouse gas into the atmosphere was the state’s reliance on coal for power.

While coal is still a big source of energy in Minnesota — and a big source of greenhouse gas emissions — its impact has diminished somewhat. In 2007, coal made up 59 percent of the state’s electricity generation, compared to 39 percent in 2017. In the same period, renewables went from 8 percent to 25 percent of energy generation. Natural gas, which pollutes less than coal, increased from 7 percent to 12 percent, according to the Minnesota Commerce Department.

Those reductions were partly driven by state policies, such as the Renewable Energy Standard, requiring utilities to generate more electricity from renewable sources.

Switching from coal to cleaner sources of power has helped the state reduce its emissions from energy generation by 29 percent since 2005 overall, making it the shining star of industries in terms of greenhouse reductions, said Mary Jean Fenske, MPCA air policy unit supervisor.

“We’re getting more of our electricity coming from renewables like wind, and also more from natural gas, which are much cleaner sources,” Fenske said.

The MPCA expects to see continued reductions in greenhouse gas emissions from power generation as renewable energy becomes cheaper to generate and as utilities retire coal-powered plants. Between 2018 and 2026, nine coal-powered plants are slated to shut down.

Transportation lags

Not all greenhouse gas sources have seen such dramatic drops.

Case in point? Transportation, which has seen a smaller reduction in emissions: 8 percent since 2005. Transportation, including passenger cars, light and heavy-duty trucks, aviation, trains and other modes of transportation, is now the biggest producer of greenhouse gas emissions in Minnesota.

That’s despite cars getting more fuel-efficient. In 2005, the baseline year for Minnesota’s energy goals, the average car or truck went about 20 miles per gallon of fuel, according to the Environmental Protection Agency. Today, that average is more than 25 miles per gallon.

But even as cars get more fuel-efficient, they’re getting bigger. As the economy has gotten better and gas has gotten cheaper, Minnesotans are choosing bigger vehicles again, contributing to growing emissions from light-duty trucks (that includes pickup trucks, SUVs, vans and crossovers), which make up 38 percent of transportation emissions, up from 34 percent in 2005. In 2011, light-duty trucks overtook passenger cars as the main vehicles on the road. Today, they make up about 57 percent of passenger vehicles on the road, compared to 43 percent that are smaller cars.

Minnesotans are also driving more miles. After seeing reductions, the number of vehicle miles driven per resident of the state has increased slightly to about 10,800.

Unlike energy generation, where the actions of fewer big actors — power companies — make a big difference,  transportation depends more on the everyday choices made by Minnesotans.

“We continue to see people shifting to some of the larger vehicles, said Kari Palmer, of the MPCA. “Even though the larger vehicles are cleaner (than they were), they aren’t as fuel efficient as the smaller vehicles.”

Further complicating the policy picture for the state, transportation emissions have tended to be the purview of the federal government. The EPA has imposed regulations on vehicle emissions; if states want to impose stricter ones they need to get a waiver from the federal Clean Air Act. Only a few have. (The waivers or the standards themselves may get rolled back, something that President Donald Trump’s administration has discussed.)

Since transportation emissions make up such a big piece of the pie, decreasing them could be a big part of meeting the state’s 2025 goal to lower emissions by 30 percent below the 2005 baseline, and an 80 percent reduction by 2050.

To reach the 2015 reduction goal of 15 percent in just the transportation sector in 2016, the average Minnesotan would have to drive an estimated 1,500 fewer miles per year, wrote Frank Kohlasch, of the MPCA, in an email.

The MPCA expects to see reductions in emissions due to transportation as electric vehicles get less expensive and easier to charge. But even as Minnesotans do start to adopt electric vehicles, the change takes time, since people don’t switch out their cars every year.

Developing less carbon-intense fuel sources, making it easier for people to use public transit, walk or bike to destinations, are among other things that would help Minnesota reduce transportation emissions, Kohlasch wrote.

Reductions in other industries, including agriculture, forestry and land use (22 percent of greenhouse gas emissions), industrial (13 percent), residential (6 percent), commercial (5 percent) and waste (1 percent) would also help Minnesota work toward meeting its emissions goals.

A silver lining

Minnesota may have missed the mark on its 2015 greenhouse gas reduction goal, but there’s a silver lining in the report.

The fact that Minnesota has reduced its emissions even as its population and its economy grows shows the relationship between growth and greenhouse gas emissions is weakening, the MPCA says: average emissions per person are lower than they were in 2005, as have emissions per dollar produced by the state’s economy.

“What this means is that our state economy can grow without increasing greenhouse emissions,” the report says.