His second inaugural speech included a pledge to fight climate change -- but a spokesman is disputing the notion that President Barack Obama waited until his second term to tackle the issue.

Jay Carney says climate change is an "important issue" and a priority for Obama -- but that it's "one of a host of priorities he believes we can act on."

Obama said in his speech that failing to respond to the threat would "betray our children and future generations."

Environmentalists say Obama's first test on the issue could come early this year as he decides whether to approve the Keystone XL oil pipeline that will carry tar sands from Canada to Texas. The State Department is reviewing it, and is expected to make a recommendation as soon as April.

Obama blocked the pipeline last year, citing uncertainty about the project's path through environmentally-sensitive land in Nebraska. But today, Nebraska's Republican governor is endorsing an alternate route.

Republicans and many business groups say the pipeline would help achieve energy independence and create thousands of jobs.

The State Department says it will study a letter from the Nebraska governor and the state's environmental report as it completes its review of the pipeline.

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