It’s Earth Day, which means government agencies are shooting off press releases touting their efforts to conserve energy through various green initiatives. But sorry, other government flacks — the Central Intelligence Agency’s method of reducing its carbon footprint takes the cake.

Turns out the CIA saves energy by shredding and burning classified documents.A press release from the CIA explains that their “burn after reading” practice conserves energy because the exhaust from their incinerator generates steam to heat water at CIA headquarters. Says the CIA:

In addition to saving fuel, that process reduces the amount of waste–which would otherwise be destined for landfills–by nearly 1,000 tons per year. The CIA increases its recycling efforts each year, annually collecting over three tons of plastic, glass, cardboard, aluminum, construction debris, and other waste.

“As our nation marks Earth Day, Americans must find even more ways to promote energy conservation and preserve the environment,” CIA Director Leon E. Panetta said in the news release. “This is a moral responsibility. The Agency’s sustainability efforts also save taxpayer dollars.”

The CIA also pointed out that their most recently built facilities have a Gold LEED rating from the U.S. Green Building Council and “consume over 20 percent less energy and approximately 40 percent less water than typical buildings of the same size and use.”

CIA employees also enjoy energy-efficient lighting in interior spaces and the parking lot at Langley headquarters, which they say “reduces consumption and heat output from traditional lighting fixtures.”

[Correction: The CIA conserves energy by heating their water with incinerator steam, but the process doesn’t actually produce any additional power.]