Depending on when he formally takes the reins at the State Department, John Kerry may find himself facing an early decision on whether to recommend approval of the controversial Keystone XL pipeline, which environmentalists have vociferously opposed on grounds that it would be devastating for climate change.

For now, the Massachusetts Democrat is declining to say how he would decide.

"I'm not going to comment on that now," Kerry said on his way to the Senate floor yesterday when asked whether Keystone should be approved. "I've got confirmation hearings -- you'll hear about it."

Environmentalists in general are optimistic about Kerry's nomination to take over for Hillary Rodham Clinton as secretary of State (E&ENews PM, Dec. 21, 2012). He led the effort three years ago to push a cap-and-trade bill to limit greenhouse gas emissions, although he ultimately was unsuccessful, and he has been vocal about the need to confront climate change.

The fate of the Keystone pipeline, which would transport crude extracted from Alberta's oil sands to refineries in Texas, is seen as a key early test of President Obama's second term. The administration has signaled that a final decision could come within the next three months.

TransCanada, which hopes to build the pipeline, has said it is optimistic its permit to cross the U.S.-Canada border ultimately will be approved, although local and national environmental groups continue to fight it on several fronts, including through lawsuits and occupations along the pipeline's route aiming to halt construction.

Kerry, who currently serves as chairman of the Senate Foreign Relations Committee, has previously said he would study the pipeline closely but has not taken an explicit position on whether it should be constructed. He voted against a measure aimed at overturning Obama's rejection of the pipeline, calling the ensuing controversy a "completely trumped-up, phony issue" (ClimateWire, March 9, 2012).

Obama rejected the pipeline last year, citing concerns related to its route through Nebraska. TransCanada has since rerouted the line, and Nebraska regulators recently completed a new environmental review.

Sen. John Hoeven (R-N.D.), one of Keystone's biggest proponents, said he would urge Kerry to support the pipeline but stopped short of committing to employing procedural tactics to block the nomination in order to extract concessions on its approval.

"It's certainly something I'm going to discuss with him," Hoeven said in a brief interview yesterday. "Where it goes from there, it's too soon to say."