Fourteen federal agencies have spent at least $70 billion on climate change-related activities since 2005, but most refuse to tell Congress and taxpayers how the money is being spent.

The actual amount may be much higher, according to the Congressional Research Service, because the data it obtained "likely represent[s] an underestimate of federal funding for the period, perhaps on the order of tens of millions of dollars."

President Obama's "climate change action plan" instructs federal agencies to reduce their climate change-related emissions, but the spending involved began under President George W. Bush.

The agencies were asked in August by the House Committee on Energy and Commerce to provide witnesses to discuss their climate change spending at a Sept. 18 hearing. All but two of the agencies declined, claiming scheduling conflicts.

The committee requested information on climate research; climate-related regulations proposed, issued or in process; climate-related grant programs agencies participated in; cooperation between agencies; and spending on these activities.

When the committee sent a follow-up letter Sept. 4 extending the request to any available staff member, the agencies still declined.

The committee's third request was an Oct. 24 letter containing a Nov. 22 deadline, but a committee spokesman said no answers have been received.

“The president is further expanding the federal government's climate change activities, yet the administration has not been willing to answer straightforward questions and account for the federal climate programs that are already underway," Rep. Ed Whitfield, R-Ky., chairman of the panel's subcommittee on energy and power, told the Washington Examiner.

Whitfield isn't the only committee member frustrated by the agencies non-responsiveness.

"Are you trying to hide something? Are you embarrassed by it? Or you just don't care to respond to the Congress?" Rep. Joe Barton, R-Texas, asked at the Sept. 18 hearing.

"We're trying to have a good-faith effort here to have a real dialogue, but in order to have the dialogue, we have to have the facts, and we're being stonewalled. Which means the American people are being stonewalled."

Only the Environmental Protection Agency and the Department of Energy sent witnesses to testify at the hearing.

Absent from the hearing were the departments of Health and Human Services, Agriculture, Interior, and State. Also absent were the U.S. Agency for International Development, the Export-Import Bank, the White House Office of Science and Technology Policy, the National Oceanic and Atmospheric Administration, and NASA.

According to a committee spokeswoman, the Department of Defense originally identified a witness, then changed its mind, also citing a scheduling conflict.

"The Department of Defense was unable to provide a witness to the climate change hearing," DOD spokesman Mark Wright told the Examiner.

"The Department of Defense is working now on providing proper answers for the House Energy and Commerce Committee's questions, and these will be delivered to the committee as soon as they are ready."

The Department of Transportation did not send an official to the hearing because “EPA Administrator McCarthy and Energy Secretary Moniz served as representatives for the Obama administration," a spokesman said.

"DOT has always made an effort to share information on its work with lawmakers, including most recently its efforts to address the impact of climate change in our Hurricane Sandy rebuilding efforts, which can be found here,” the spokesman said.

An Export-Import Bank spokesman said the bank was unable to send a representative to the hearing but is "working on" a written response.

The Energy Department received the bulk of the funding, at $50 billion between 2005 and 2012, most of which went toward technology development and deployment, according to CRS.

NASA received the second-highest amount, at nearly $7 billion. Most of the other agencies received $1 billion or less each.