While natural gas can reduce greenhouse emissions when it is substituted for higher-emission energy sources, abundant shale gas is not likely to substantially alter total emissions without policies targeted at greenhouse gas reduction, a pair of Duke researchers find.
If natural gas is abundant and less expensive, it will encourage greater natural gas consumption and less of fuels such as coal, renewables and nuclear power. The net effect on the climate will depend on whether the greenhouse emissions from natural gas -- including carbon dioxide and methane -- are lower or higher than emissions avoided by reducing the use of those other energy sources.
Most evidence indicates that natural gas as a substitute for coal in electricity production, gasoline in transport, and electricity in buildings decreases greenhouse gases. But natural gas production and consumption has higher emissions than renewables and nuclear power.
"Over the range of scenarios that we examine, abundant natural gas by itself is neither a climate hero nor a climate villain," said Richard Newell, Gendell Professor of Energy and Environmental Economics and director of the Duke University Energy Initiative.