Canada says sees no net increase in emissions from Keystone

TORONTO (Reuters) - Canada does not think there would be a net increase in carbon emissions if TransCanada Corp builds its proposed Keystone XL pipeline from Alberta's oil sands to Texas, Natural Resources Minister Joe Oliver said on Tuesday.

Earlier in the day, U.S. President Barack Obama had indicated he would block the pipeline if it significantly increased the problem of carbon pollution and said the net effects of its impact on the climate would be a critical factor.

"On a net basis, we don't see any increase in emissions as a result of the construction of the pipeline," Oliver told reporters in Toronto. He said at least 20 percent of the oil transported by Keystone would be lighter grades of crude that would not come from the tar sands and would therefore not be carbon intensive to produce.

(Reporting by Cameron French, writing by David Ljunggren; Editing by Gary Hill)