A natural choice
IN AMERICA'S climate debate, one of the most promising developments of recent months has been the growing recognition in Washington that natural gas may play a key role in curbing carbon emissions. The resurgence of gas comes through the discovery of massive deposits in Appalachian shale formations and elsewhere -- a reserve that offers the prospect of stable domestic supplies and relatively low prices. Since burning natural gas produces half the emissions of burning coal, switching the two fuels could put a significant dent in America's carbon footprint.
The rumor this month was that such arguments had swayed the White House and that President Obama would back policy aimed at discouraging coal and encouraging natural gas at a speech he delivered to the Business Roundtable on Wednesday. The rumors didn't bear out. That's too bad. With climate-change legislation still stalled in Congress, nudging gas forward is something that the government can do quickly and relatively cheaply to meet its medium-term emissions goals if current trends persist.
To be sure, America doesn't want to depend too much on one commodity. Drastically ramping up the amount of natural gas burned to generate electricity would require infrastructure investments in certain regions as well as retrofits of certain plants or the construction of entirely new ones.
But existing gas-fired plants are running at only about 25 percent capacity, in part because many are switched on only when demand spikes. The Congressional Research Service reports that doubling the use of existing plants could replace about a third of coal-fired power, getting America a third of the way to its goal for 2020. For reasons of infrastructure, that might be too optimistic a scenario. But BP -- which has a stake in natural gas -- estimates that retiring the 80 dirtiest coal plants and replacing them with gas-fired power would get America 10 percent of the way to its 2020 emissions target and increase domestic gas consumption by only 5 percent.
Even if you don't trust BP's numbers, a range of attractive policy options is available, starting with tax incentives to decommission old coal plants. Natural gas is so competitive, it might not take much more than that. However, policymakers might also consider coupling that with some carrot to switch to gas. States that demand that utilities derive a certain portion of their electricity from clean sources could also allow natural gas to count in such requirements, discounting for the carbon emissions it does produce. Federal legislators contemplating a similar, national standard might also consider this.
In the long term, natural gas is only a bridge fuel as America weans itself off carbon, since it still produces plenty of emissions. With a rising carbon price, natural gas will become too expensive to burn. But it can provide the country some time to bring to market the cleaner technologies on which America eventually must run.