President Obama has tapped Gina McCarthy, current assistant administrator at the Environmental Protection Agency's Office of Air and Radiation, to serve as the agency's administrator. Obama also picked Ernest Moniz, former undersecretary of energy during the Clinton administration and currently a physicist at the Massachusetts Institute of Technology, to lead the Dept. of Energy.

While both are expected to be confirmed, some environmental groups have expressed reservations about Moniz's support for natural-gas development and nuclear power. McCarthy could face some tough questioning from lawmakers about upcoming EPA regulations, including rules on post-construction stormwater, ozone and fracking emissions, says Leah Pilconis, Associated General Contractors of America senior environmental adviser.

Courtney Abrams, Environment America's clean-energy advocate, says Moniz "has a history of supporting dirty and dangerous energy sources like gas and nuclear power." But those concerns are unlikely to cost Moniz the confirmation, says Scott Segal, an energy lobbyist with the Washington, D.C., offices of Bracewell & Giuliani.

McCarthy, who at the EPA oversaw the development of several regulations to reduce air pollution, also has served as a top environmental official in Massachusetts and Connecticut. "She has state-level experience on a wide variety of environmental issues," says Pilconis.

While some industry groups complain that many of the air-related rules EPA developed under McCarthy were overly burdensome, Kevin Crapsey, a vice president at Louisville, Ky.-based Eco Power Solutions, a provider of multi-pollutant emissions-control technology, says, "Most of our senior management [found] McCarthy to be tough on emissions but fair to the industry."

He adds, "McCarthy's EPA can lead the effort to address climate change with a minimal impact on electricity consumers—with realistic time lines for impacted industries and incentives for reducing emissions."