The Senate Environment and Public Works Committee will wade into a controversial topic next week: The greenhouse gas footprint of the U.S. natural gas drilling boom.

A subcommittee will hear Tuesday from a senior Environmental Protection Agency official and other experts at a hearing on “fugitive methane emissions from oil and gas operations.”

Here’s the basic issue:

The natural gas boom is helping to drive down U.S. carbon emissions as power companies switch from coal to gas, which emits far less carbon when burned to create electricity.

But emissions of the potent greenhouse gas methane at well sites and other points on the development chain undercut some of the advantage.

Some gas critics, including a pair of Cornell University professors, contend the problem is serious enough to make gas produced from shale formations – the stuff tapped by fracking – as bad for the climate as coal.