A government agency that investigates federal spending has singled out climate change as an event that could pose a "significant financial risk" to the U.S. government.
The Government Accountability Office said Thursday that climate change can increase the intensity and frequency of weather disasters, putting the U.S. in a position to spend more money on response efforts.
The Federal Emergency Management Agency has already obligated more than $80 billion for disasters declared between fiscal years 2004 through 2011, the agency says.
The GAO report, which listed other "high-risk" issues facing the federal government, comes as President Barack Obama steps up his focus on climate change heading into his second term.
The GAO compiles a list on "high risk" issues facing the federal government every two years. The warnings on climate change were added for the first time this year.
Mr. Obama, while delivering the State of the Union address this week, urged Congress to develop a market-based plan to address greenhouse-gas emissions. Mr. Obama said he would direct his own agencies to tackle the issue if Congress failed to do so.
A Democratic-controlled House passed a bill in 2009 that created a greenhouse-gas trading program, but the Senate, also controlled by Democrats, didn't vote on the measure.
Sen. Barbara Boxer (D., Calif.), who leads the Senate Environment and Public Works Committee, and Sen. Bernie Sanders (I., Vt.) unveiled legislation Thursday that would impose a fee on carbon dioxide emissions, also known as a carbon tax. Revenue from the fees would be used to invest in wind and solar technologies, among other things, they said.
Sen. David Vitter (R., La.), the highest-ranking Republican on the environment committee, said a carbon tax was a bad idea. "It's not just energy prices that would skyrocket from a carbon tax, the cost of nearly everything built in America would go up," Mr. Vitter said.
The White House has previously said it won't propose a carbon tax.