Environmental groups hailed President Barack Obama's warning about climate change today.
In his inaugural speech on Monday, Mr Obama pledged to respond to the threat of climate change, saying that "failure to do so would betray our children and future generations."
Climate change was often overlooked during Mr Obama's first term.
His statement sets up a likely confrontation with Republicans who have opposed legislative efforts to curb global warming and frequently deny its existence.
Erb Institute for Global Sustainable Enterprise director Andrew Hoffmans said that the president's focus on climate showed political backbone.
"He finally had the courage to acknowledge the words 'climate change'," Hoffman noted, adding that administration officials have frequently used words such as green jobs or clean energy to describe energy policy, instead of the more politically charged term.
President Obama said that some people "may still deny the overwhelming judgment of science" that global warming exists and has human causes, "but none can avoid the devastating impact of raging fires and crippling drought and more powerful storms."
The president pledged to boost renewable energy sources such as wind and solar power, along with more traditional energy sources.
Environmental groups said the president's first test will come early this year as he decides whether to approve the Keystone XL oil pipeline that will carry tar sands oil from Alberta, Canada, to Texas.
Mr Obama temporarily blocked the pipeline last year.
Republicans and business groups claim that the project would help to achieve energy independence for north America and create thousands of jobs.
But environmental groups say the pipeline would transport "dirty oil" and produce heat-trapping gases that contribute to global warming.
Mr Obama tried and failed in his first term to get a climate change Bill through Congress.