The Enbridge Line 3 crude oil pipeline is snaking across the wetlands and forests of northern Minnesota, half built now and colliding with the state's climate targets for slashing greenhouse gas emissions.

The $2.6 billion pipeline and its oil, the largest project in Minnesota to have its related global warming gases fall under court scrutiny, will result in 193 million tons of carbon dioxide emitted each year. That's more than the entire state generates.

Meanwhile, Minnesota is failing on its legislated goal to cut greenhouse gas emissions by 30% by 2025 to fight climate change as emissions have actually increased in most sectors.

The pipeline's greenhouse gas estimates — which came from the state's own environmental review and were accepted by a judge but not by the Minnesota Public Utilities Commission (PUC) — span the full life cycle of Line 3 oil: from pumping it out of the Canada tar sands, to piping it, refining it and burning the refined products elsewhere.

In a brief filed in the ongoing legal battle over the pipeline, the PUC called the greenhouse gases associated with Line 3 "a significant consequence." But it also wrote that the project "would not significantly contribute to greenhouse gas emissions because the oil transported through the pipeline is not produced by the pipeline."

Minnesota tribes and environmental groups battling Line 3 say that is dangerously out of sync with the national shift underway in addressing climate change.

"It's preposterous," said Winona LaDuke, executive director of Honor the Earth and a member of the White Earth Band of Ojibwe. "The PUC has entirely missed the picture. It [greenhouse gases] has to be factored into all public decisions."

In his report "A Giant Step Backward" Macalester College physicist Jim Doyle calculated the cradle-to-grave emissions associated with Line 3 are equivalent to firing up 50 new coal-fired power plants.

The Line 3 case before the Minnesota Court of Appeals is about whether the PUC appropriately evaluated the long-range demand forecast for crude oil in determining whether Enbridge needs the pipeline.

The question of the heat-trapping gases came up during a recent hearing.

"This is one of the dirtiest energy sources on the planet," said Brent Murcia, a student lawyer representing a group called Youth Climate Intervenors. "The PUC's decision to not adopt that quantification should be seen for what it is, and that's just an implausible excuse to avoid quantifying the emissions in order avoid reckoning how big their impacts are."

Judge Lucinda Jesson responded that her reading of the PUC's argument was that it acknowledged a "substantial environmental impact" but balanced it against other society factors.

"Was that not a fair reading?" she asked Murcia.

Acknowledgment is not enough, Murcia said.

Neither Enbridge, the PUC nor the state Department of Commerce addressed greenhouse gas in their testimony.

In court documents, the PUC and Enbridge argue the emissions were properly weighed.

Shipping the oil by truck or rail would be even more dangerous, they say, and most of the greenhouse gases will occur from burning oil products — consumption that would happen whether or not the pipe is built. The PUC said it rejected the emissions calculations as too vague, based on a range of estimates from studies that aren't transparent enough.

In an e-mail, Enbridge said it thinks the environmental review "reinforces that pipelines in themselves have relatively minor emissions."

"Truth is, as long as most of us desire modern conveniences, what is in Line 3's pipeline will be needed — to drive, cook, heat our homes, fly on planes and manufacture products," said Enbridge spokeswoman Juli Kellner. "Millions of products made of poly fibers and plastics — from computers to heart monitors, from medical supplies to shoes, warm winter coats and camping gear — are today dependent on crude oil."

Bigger role in assessments

Greenhouse gases are likely to play a larger role in environmental assessments of big Minnesota projects.

Gov. Tim Walz, who has called climate change an existential crisis, has created a climate subcabinet. The Minnesota Environmental Quality Board is working to require agencies and local governments to integrate greenhouse gas pollution into environmental assessments. The Minnesota Pollution Control agency has started requiring greenhouse gas accounting for all future animal feedlots after a 2019 Minnesota Appeals Court decision forced the agency to re-examine the permit of a mega dairy.

Change is also afoot nationally.

The Federal Energy Regulatory Commission (FERC) on March 18 for the first time assessed the impacts of greenhouse gases from a natural gas pipeline. It concluded that the emissions from the line Northern Natural Gas Co. wants to build in South Dakota "would not be significant."

But in a news release, FERC Chairman Rich Glick wrote: "A proposed pipeline's contribution to climate change is one of its most consequential environmental impacts and we must consider all evidence in the record — both qualitative and quantitative — to assess the significance of that impact."

Consensus is not easy. Even the PUC was divided on Line 3 when it gave Calgary, Alberta-based Enbridge its final blessing last year.

In his 11-page dissent to the decision, PUC Commissioner Matt Schuerger, an electrical engineer, said the amount of greenhouse gases associated with Line 3 are substantially at odds with Minnesota policies to cut greenhouse gas emissions.

"This project, which makes the transportation and consumption of fossil fuels easier and more economical, is incompatible with the energy policies of Minnesota and should weigh heavily against granting a certificate of need for this project," Schuerger wrote.

"The likely effect of this project is that, by promoting consumption of oil, it will thwart the aims and responsibilities of the state established in many Minnesota energy and environmental policies."

Correction: A previous version misstated the estimated amount of emissions annually from the pipeline and its oil.