Minnesota will adopt stricter emissions standards for cars, trucks and SUVs, aligning itself with California in a battle with the Trump administration over energy conservation and air pollution.

Minnesota thus becomes the 15th state to move in such a direction. California has taken the lead with its fuel-efficiency laws requiring auto manufacturers to meet escalating mile-per-gallon targets for passenger vehicles through 2025.

The move, announced Wednesday afternoon by Gov. Tim Walz, comes as the U.S. Environmental Protection Agency and Department of Transportation prepare to weaken federal fuel-efficiency standards set during the Obama administration and threaten to revoke an exemption that Congress has long given California to set its own, tougher targets.

Walz said it will take about 18 months for Minnesota to adopt the new emissions standards following public hearings. “It just makes sense,” he said in an interview. “It saves money on gas, it increases options and choices, reduces Minnesota’s carbon emissions and improves health.”

In addition to improving fuel economy, Walz said he expects the standards to reduce the state’s total greenhouse gas emissions by 4.5 to 5% within five years. Those reductions would help Minnesota creep closer to emissions goals it has long failed to meet that were set by bipartisan legislation in 2007.

Court battle underway

It is unclear, however, if Minnesota will ultimately be allowed to adopt the standards as the Trump administration and California wage a court battle over the right of states to set regulations of their own. California — by itself one of the largest car markets in the world — has been allowed to set its own emissions standards since Congress adopted the Clean Air Act in 1970. Other states have had the option of adopting either the California rules or those set by federal regulators until last week, when President Donald Trump announced that his administration would revoke California’s authority to set its own standards.

California, along with 23 other states, including Minnesota, sued the administration to keep that authority in place.

“The anticipation is we will win this case, so we need to be prepared for once that happens,” Walz said.

The decision drew criticism from state Republican leaders even as Walz was announcing it to reporters.

“The governor doesn’t get to unilaterally decide how Minnesotans live their lives,” state House Majority Leader Paul Gazelka, R-Nisswa, said in a statement. “These goals are unrealistic to be adopted or met by everyday Minnesotans.”

But Consumer Reports, the independent product-testing publication, praised Walz’s decision as a “breath of fresh air.”

“This decision is a win for all Minnesota families, and a great example of leadership for other states that have not yet adopted low emission vehicle standards,” said Shannon Baker-Branstetter, Consumer Reports’ manager of cars and energy policy.

The White House has not proposed its own final rules to replace the ones set under President Barack Obama but has signaled that it might freeze those standards at 2021 levels. If that were to happen, a car manufacturer’s fleet of new vehicles would have to average 30 mpg in real-world driving by 2021. The Obama-era rules would have gradually raised that to an average of 36 mpg by 2025.

Fuel savings

The Trump administration contends that freezing fuel-economy standards will reduce the average sticker price of new vehicles by about $2,700. But a study released by Consumer Reports in August found that those savings would be wiped out for the average driver by an extra $3,000 in fuel purchases over the life of the vehicle if the standards are frozen at 2021 levels.

Walz said the freeze proposed by the Trump administration would be an unprecedented setback after decades of steady progress on cleaner, more efficient cars. “It just makes absolutely no sense to the consumer,” he said. “We’re all happy when we get better gas mileage. This will simply take us back.”

If the California standards are adopted in Minnesota, the average emissions from new cars in an automaker’s fleet would be required to drop by 5% a year through 2025. Emissions from trucks and SUVs would fall by 3.5% a year over the next two years, and then 5% a year from 2021 to 2025.

Hybrids and e-vehicles

Manufacturers would also be required to offer consumers an increasing number of electric or hybrid vehicles with ultralow or zero tailpipe emissions every year.

The new standards will help cut Minnesota’s greenhouse gas emissions in a sector of the economy that’s proved to be one of the hardest to cut, said Laura Bishop, commissioner of the Minnesota Pollution Control Agency.

Minnesota lawmakers set a bipartisan goal in 2007 to cut the state’s carbon emissions 15% by 2015 and 80% by 2050. The state fell far short of the 2015 goal and is well behind meeting future goals, even though emissions from power plants and energy production have fallen drastically.

One major reason is that emissions from cars, SUVs and other vehicles have remained virtually flat every year since 2009. By 2025, the new standards will cut vehicle emissions by 10%, Bishop said. “That’s significant and will help us get on track,” she said.

In 2007 and 2008, Minnesota lawmakers considered but rejected legislation to adopt the California standards. State Rep. Rick Hansen, D-South St. Paul, said he supports the governor’s decision to use his rule-making authority instead.

“We have to take action with the climate crisis,” said Hansen, chairman of the House environment committee. The changes won’t affect cars currently on the road or hinder the sale of trucks and SUVs, Walz said.

“If you want to drive your pickup, go ahead and drive your pickup,” Walz said. “This has no impact whatsoever on the choices Minnesotans are free to make other than expanding opportunity and to make sure the fleet overall is looking at carbon emission reductions.”

This report contains material from the Associated Press.

Correction: Previous versions of this article misstated the kinds of rules that Minnesota is putting in place. They are stricter emissions standards.