This morning, EPA Administrator Gina McCarthy announced proposed regulations that call for a 30 percent reduction by 2030 in carbon dioxide emissions from existing power plants. But it’s not 30 percent from today's levels. It’s 30 percent from where the U.S. was in 2005— when emissions were a lot higher. In fact, they’ve dropped 15 percent since then. If the country has already coasted halfway to the finish line, the next half promises to be tougher.
It's worth remembering that the last nine years haven’t been an easy ride. "The biggest thing since 2005 has been the slow economic times since 2009, so that’s nothing to get excited about," says Lucas Davis, an energy economist at the University of California at Berkeley. The recession meant lower demand for energy— especially from industries that use electricity to run factories.
Doug Vine at the Center for Climate and Energy Solutions offers another contender for what’s been driving emissions down: "The largest force is the natural gas boom that we’ve seen in this country," he says. Burning natural gas emits about half as much carbon dioxide as coal for the same amount of energy.
However, another trend that's pushed emissions down—more efficiency, more solar, and more wind power — stems partly from higher natural gas prices, from the years before 2005.
"Those increases in natural gas prices were leading to increases in electricity prices," says Susan Tierney of the Analysis Group, "and that was making a lot of people very concerned." Those concerns prompted a lot of states to start promoting wind and solar power, and energy-efficiency.
That trend got a push from the federal government. "The 2009 federal stimulus put a big slug of money into energy efficiency and renewable energy," says Dan Bakal of Ceres. The American Recovery and Reinvestment Act included $31 billion in energy programs, with the biggest chunk going toward energy-efficiency.
But the stimulus is over. The recession too. Natural gas prices have started going back up, and coal is making a small comeback. WIthout a policy like the EPA’s new regulations, analysts say we would expect to see greenhouse gas emissions start going up again.