As the battle over the Keystone XL pipeline sharpened this week at State Department hearings in Nebraska, Canada's ambassador to the United States called for approval of the giant pipeline intended to carry oil from Alberta and North Dakota south across the Great Plains.

Speaking to the Minnesota International Center on Friday on the 50th floor of the IDS Center, Gary Doer said the pipeline would produce fewer greenhouse gas emissions than transporting oil by train, and would draw the United States, Canada and Mexico closer to the goal of North American energy independence.

"To us, it's part of an energy vision," said Doer, the former premier of Manitoba. "That will be a huge game-changer in terms of geo-security issues for the United States and for North America."

He said oil from the Middle East and Venezuela would become less crucial, the pipeline would create jobs and allow Canadian firms to get oil to market more easily. Additionally, he said, it can be built safely without causing more harm to the environment.

The pipeline would travel from the Canadian border at Morgan, Mont., through North Dakota and South Dakota to Steele City, Neb. It would be 875 miles long and carry oil from Alberta and North Dakota to other pipelines that run to refineries on the Texas Gulf Coast.

The State Department issued a draft of an environmental-impact statement last month, finding that blocking or approving the pipeline — either way — would fail to substantially affect greenhouse gas emissions or halt the controversial extraction of oil from northern Alberta's tar sands. The report also said aquifers on the Great Plains would not be at risk from the pipeline, and the project would create 42,000 jobs directly and indirectly.

Environmental groups such as the Natural Resources Defense Council have rejected some of the State Department's findings, arguing that the pipeline would lead to a spike in oil extraction from Alberta, where the oil that's pulled from the sand produces 17 percent more greenhouse gases per barrel over its life cycle than an average barrel of oil.

Doer said Friday that he sides with the State Department's report. The State Department held hearings over the pipeline in Nebraska this week, and eventually will decide whether the project moves forward.

"The State Department correctly pointed out that oil from Canada will not increase greenhouse gases if the pipeline's approved, because it's now basically coming down on train," Doer said. "In fact, trains will have an 8 percent higher greenhouse gas [emissions] than a pipeline. So this is part of making the United States energy independent from the Middle East, it's part of displacing unreliable oil from Venezuela. It creates 42,000 jobs, and in Minnesota, a lot of your oil comes from Canada."

Alberta oil sands operators have greatly cleaned up their process in recent years, Doer said.

"We believe in clean air and clean water, and we're going to have to keep working on it," he said.

The rapid rise of oil shipment by rail has complicated the argument over the pipeline, and given it clearer implications for Minnesota. Canadian National and Canadian Pacific, two railroads with big stakes in Alberta, both have U.S. entry points in Minnesota.

Both railroads have been investing in tank cars and oil-loading terminals. Canadian National increased its oil shipments sixfold in 2011. Excluding those two railroads, U.S. petroleum shipments by rail have spiked 56 percent so far in 2013, to 202,173 carloads through April 13, according to the Association of American Railroads.

This increase in rail oil traffic has risks. A Canadian Pacific train carrying oil from Alberta derailed about 20 miles north of Alexandria, Minn., on March 27, spilling roughly 350 barrels of oil into the snow. The Wall Street Journal reported 112 rail oil spills in the United States between 2010 and 2012, compared with 10 in the previous three years. However, the volume of spilled oil from rail has declined since 2008.

Adam Belz • 612-673-4405 Twitter: @adambelz