Tar-Sands Oil Pollutes Less Than Thought, Report Says

(Bloomberg) — Tar-sands oil from Canada, the biggest supplier to the U.S., is cleaner than previously calculated, according to an Alberta government report that may benefit producers Nexen Inc. and Royal Dutch Shell Plc.

Carbon-dioxide emissions from producing oil in western Canadian sand deposits are about 10 percent higher than competing U.S. crude imports, the Alberta Energy Research Institute said in the report. Earlier studies found discharges of greenhouse gases were as much as 40 percent more. The study was received with skepticism by an environmental group.

Nexen and Shell are among oil companies facing possible import barriers into the U.S., their biggest market, under new environmental rules being considered in Congress to limit emissions from gasoline and other transportation fuels. Canada sells about 60 percent of its tar-sands oil to U.S. refineries.