President Obama's nomination of Senator John Kerry (D-Mass.) as Secretary of State on Friday presents a potential opportunity for climate action, according to environmental organizations.

Gene Karpinski, President of the League of Conservation Voters, released a statement praising the decision. “Senator Kerry is a true leader on climate change and other environmental issues and has spent his career advocating for policies that are good for our planet and our national security."

Environmental group 350.org's spokesperson Daniel Kessler told HuffPost in an email statement, "Sen. Kerry will have some stout challenges ahead of him, made even more perilous if we don't get serious about tackling the climate crisis now. The president has said that we need to move 'forward' -- with Sen. Kerry on board, they can get to work on getting us off of fossil fuels, beginning by saying no the Keystone XL tar sands pipeline."

Kerry told the U.S. Senate in August that climate change is "of as significant a level of importance" as Syria or Iran's nuclear ambition, as it "affects ecosystems on which the oceans and the land depend."

He also lashed out at climate deniers this year, stating, "The falsehood of today’s naysayers is only matched by the complacency of our political system... We should be compelled to fight today’s insidious conspiracy of silence on climate change."

In a 2004 presidential debate against George W. Bush, Kerry said his opponent failed to address climate change and "didn't even accept the science." He declared he would be "a president who believes in science."

An attendee of the 1992 U.N. environment conference in Brazil, Kerry also co-authored the "last major climate bill anyone tried to pass in the Senate," according to Mother Jones.

As Secretary of State, Kerry will take over Hillary Clinton's global climate change and clean air initiative. Announced earlier this year, the coalition includes the EPA Administrator and representatives from four other founding partner countries, and is designed to address "short-lived climate pollutants." According to the State Department, these pollutants "account for more than a third of current global warming."

Under the Obama administration, the State Department has also furthered bilateral partnerships on climate and clean energy between the U.S. and several nations, including India, China, Indonesia and Mexico.

If confirmed, Kerry will shoulder the growing pressure on the Obama administration to act on the Keystone XL pipeline. The polarizing project requires State Department approval, as it crosses the U.S. border with Canada.

In October 2011, Kerry said on Keystone in a statement to The Hill, "There's a lot at stake here and I’ll do my best to leave no question unanswered including every possible economic and environmental consideration before a final decision is made."

“For two years now, I've had the Foreign Relations Committee conducting regular oversight of the permitting process because of concerns about Keystone XL," he added. "We’ve hosted several briefings with the State Department to discuss the environmental impact assessments as well as the process for determining the national interest."

Earlier rumors of U.N. Ambassador Susan Rice receiving the nomination drew concern from environmentalists, who worried that Rice's investments worth several hundred thousand dollars in the pipeline's builder, TransCanada, may have heralded the controversial oil sands pipeline's approval by the State Department.

In the weeks before Kerry was officially nominated, Russ Girling, the CEO of TransCanada, defended the likelihood of Keystone XL construction. Girling claimed a new Secretary of State eyeing tougher greenhouse gas policies should not impact the pipeline approval decision. He also suggested that the pipeline would not greatly impact North American greenhouse gas emissions, although activists call oil sands crude, or diluted bitumen, "the dirtiest oil on the planet."

Clarification: Language has been amended to more accurately characterize the climate and clean air initiative that the State Department is coordinating with the UN.

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