Canada's National Energy Board on Thurday gave the official green light to the Mackenzie Valley natural gas pipeline, according to The Globe and Mail. The board's issuance of a certificate of public convenience and necessity came after Canada's federal Cabinet had approved the project and appeared to be the last regulatory hurdle facing the $16 billion, 743-mile pipeline. Canadian officials hope to tap Arctic gas reserves "discovered decades ago" via the Mackenzie project. "But the high cost of the project, along with the discovery of huge new volumes of natural gas in more southerly parts of the continent, have raised growing doubts over whether the pipeline will be built any time soon." The Globe and Mail cites backers of the Mackenzie pipeline as some Alaska energy players, old and new, including ConocoPhillips, Exxon Mobil Corp., Shell and TransCanada, the Alaska Gasline Inducement Act's $500 million lottery winner.