A new pipeline stretched to the Atlantic coast, TransCanada's Energy East project, will make Alberta's oil patch richer, but won't bring broad benefits to most Canadians, a former chief CIBC economist is arguing.

"Proponents of Energy East say the project is in Canada's national interest to build. Why is that, exactly?" Jeff Rubin wrote recently on the Huffington Post. "The clear winners will be Alberta's oil sands players."

TransCanada announced plans to build the $12-billion project last week. The 4,300-kilometre pipeline would ship oil from Alberta to refineries on Canada's east coast.

Its scale, Reuters recently reported, "is hard to understate. Were it to start in London, it would stretch all the way to Tehran. In the United States, it could pump crude oil from Beverly Hills to New York City."

Alberta Premier Alison Redford has called the pipeline "a nation-building project that will diversify our economy and create new jobs here in Alberta and across the country."

"To be sure," Rubin argues, "there are some economic enticements." Eastern refineries can process oil produced in Canada, rather than from overseas, and the pipeline will create construction jobs.

Yet "Quebec's refineries aren't exactly in desperate need of new supply," he writes, and well-paid construction jobs "are nice, but temporary."

Because crude from Alberta's oil sands is so difficult to produce, making the industry one of the world's priciest sources of oil, Rubin goes on, "drivers in Ontario, Quebec and the Maritimes will still pay the same price for gas."

Rubin doesn't doubt that a rapidly expanding oil sands industry "kicks off a lot of cash to Alberta, as well as Ottawa." But he asks: "What is the cost of chasing exponential production growth from the oil sands?"

News that bitumen is seeping out of the ground in northern Alberta and killing wildlife made international headlines.

The oil sands' carbon footprint will reach 104 megatons by 2020, Environment Canada predicts. Meanwhile Canada is set to miss its climate target by 113 megatons over the same time period.

"Nature put that oil in the ground," Rubin concludes. "Until we better understand the ramifications of taking it out, maybe we should think about leaving it there for a while longer."

Geoff Dembicki reports on energy and climate change for The Tyee.

Funding for this article was partially provided by the Climate Justice Project of the Canadian Centre for Policy Alternatives, with support from the Fossil Fuel Development Mitigation Fund of Tides Canada Foundation.