Canadian oil sands are a growing source of petroleum, and by the end of this year, they'll probably be the leading source of crude oil imports into the United States, according to a new study by IHS CERA. Canada is already the primary source of crude oil imports into the United States, and the country has been steadily increasing its production of crude oil from oil sands while its conventional oil production has declined. Production from oil sands more than doubled over the past nine years, growing from 600,000 barrels per day in 2000 to 1.35 million barrels per day in 2009. Assuming that production rate is sustained this year, oil sands will produce more petroleum than conventional sources in Canada this year, and U.S. imports of petroleum from Canadian oil sands will be greater than imports from any other country.

The production of crude oil from Canadian oil sands is at issue due to its environmental impacts, including water and land use, the production of tailings, and greenhouse gas (GHG) emissions. A 2005 study by DOE's National Energy Technology Laboratory (NETL) found that the production of crude oil from Canadian oil sands (actually a mix of tar-like crude bitumen and synthetic crude oil) has GHG emissions equivalent to 104 kilograms of carbon dioxide per barrel, more than four times the GHG emissions caused by producing conventional crude oil in the United States. Overall, the mix of crude oils used in the United States released the equivalent of 40 kilograms of carbon dioxide per barrel during their production.