

The Valero refinery works glow in the dusk light in Port Arthur, Tex. (Michael S. Williamson/The Washington Post)

The Environmental Protection Agency's proposal to curb carbon dioxide from existing power plants has sparked both plaudits and critiques alike, with environmentalists calling it a critical way to save the planet and industry opponents predicting that it will devastate the economy.

But here's a secret: The agency's previous efforts to impose the first-ever carbon limits on passenger cars and light trucks will do more — by just a smidgen — to address climate change.

By 2030, according to EPA estimates, the new power plant proposal will cut 550 million metric tons of annual carbon dioxide emissions. The fuel efficiency standards for the passenger car and light truck for the fleet years between 2012 and 2025 will cut 580 million metric tons by that same year.

In the short term, the power plant rule would make steeper cuts since the car fleet turns over gradually. By 2020, the power plant rule would cut 370 million metric tons of carbon dioxide, while the car rules will save 180 million metric tons.

"Both the power plant proposal and the vehicle efficiency rules are very significant steps, and together they mean that President Obama has addressed more than 60 percent of U.S. carbon pollution with significant standards," wrote NextGen Climate America chief operating officer Dan Lashof in an e-mail.

"Thanks to the vital safeguards proposed by the EPA today, the prolonged era of unmitigated carbon dumping may soon come to a welcome end," added Lashof, whose group is funded by climate activist Tom Steyer.