John Kerry's confirmation as secretary of state on Tuesday installs a veteran climate champion in a pole position for Barack Obama's second term.

Kerry, who describes himself as a "passionate advocate", sailed through his confirmation on Tuesday afternoon, a legacy of his nearly three decades in the Senate.

Now campaigners hope Kerry will help deliver a win on their signature issue: blocking the Keystone XL pipeline from the Alberta tar sands.

"His strong environmental record in the Senate and longtime leadership in the fight against climate change gives us hope that as secretary of state, he will reject the dangerous Keystone XL tar sands pipeline," Gene Karpinski, president of the League of Conservation Voters, said in a statement.

Kerry's confirmation also buoyed diplomatic efforts, with the European Union and environmental groups saying his appointment signalled a willingness for America to retake the lead on climate change.

After a 20-year record on climate change, dating from Kerry's attendance at the first Rio Earth summit in 1992, the defining issue for the incoming Secretary of State could well be his role in the Keystone XL pipeline.

Kerry, in his confirmation hearings last week, made it clear he would be deeply involved in the final decision about the pipeline's fate.

Obama has the final word on the pipeline. However, the state department must also sign off on the project, because it crosses the US-Canadian border. Kerry told the Senate he would closely monitor the results of an ongoing environmental review.

"I'll make the appropriate judgements," Kerry told the hearing. "There are specific standards that have to be met with respect to that review, and I'm going to review those standards and make sure they're complete."

A final determination on the pipeline will not be complete until April.

But Kerry's assertion, and his long record as one of the Senate's strongest advocates for climate action, have given campaigners' renewed hope of blocking the Keystone XL project.

Kerry told the hearing he would make climate change a top priority at the state department. "I will be a passionate advocate about this, but not based on ideology, but based on facts, based on science," he said.

Kerry also announced last week he would be divesting from oil stocks and other holdings that could present a conflict of interest with his new job. Kerry is one of the richest members of the Senate, because of his wife, Teresa Heinz Kerry's fortune.

There were also raised expectations for global climate change negotiations. Connie Hedegaard, the EU commissioner for climate action, tweeted praise for Kerry before his confirmation hearing was even scheduled.

"Confident @JohnKerry as state sec is good news for #climate. Cross fingers his dedication will make climate a strategic priority. Congrats," Hedegaard wrote.

Campaigners said Kerry's long record on the issue would enable America to play a leading role in negotiations for a global climate deal in 2015.

"President Obama's decision to put climate change at the heart of his second-term opens the prospect for secretary Kerry to push for real and measurable progress on climate change in a range of bilateral and multilateral forums," Fred Krupp the president of the Environmental Defence Fund said in a statement. "We look forward to the opportunity to work with secretary Kerry and his team as they redouble America's commitment to diplomatic leadership in confronting the climate challenge."

But Kerry is likely to have an easier time pushing ahead with existing efforts, led by the state department, to act on short-lived climate pollutants such as black carbon and methane. He led the last big push to get a climate change law through Congress, which collapsed under Republican opposition in 2010.

Kerry continued to raise concerns about climate change, using his position as chair of the senate foreign relations committee. He interrupted a hearing on Syria last August to remind senators that climate change was still a significant threat.

"Global climate change and energy security are two of the greatest challenges facing the United States today," Kerry's Senate website reads. "The crisis is growing. Carbon pollution threatens to damage our children's health and radically and irreversibly alter our climate. It threatens to bring more famine and drought, worse pandemics, more natural disasters, and human displacement on a staggering scale. In an interconnected world, the instability that would trigger endangers all of us."