President Obama’s decision to nominate Ernest Moniz as U.S. Secretary of Energy potentially places an advocate of nuclear energy and shale gas at the head of the department during a time of intense debate over the future of both. The U.S. is grappling with how to regulate, and whether to export, its booming natural gas production; and the U.S. nuclear industry has been hobbled both by cheap shale gas and debate over post-Fukushima regulations.

The organization Food & Water Watch and other opponents of fracking organized a campaign against Moniz for secretary, writing in a letter to Obama, “While we appreciate your recent public comments about the need to address climate change, appointing Dr. Moniz, a proponent of hydraulic fracturing with close ties to the oil and gas industry, would be a major step backwards.” (See related: “The Big Energy Question: How Has Fracking Changed Our Future?“)

But Joe Romm of the Center for American Progress told Greentechmedia, “An energy secretary doesn’t have the freedom to just rein in fracking — it really comes from the EPA more than any place. Plus, he understands global warming and the value of clean energy technologies. Anyone who understands that is a good choice.”

Obama also announced Monday that he would nominate Gina McCarthy as head of the Environmental Protection Agency. McCarthy, who is currently assistant EPA administrator, will have the task, among others, of shepherding proposed greenhouse gas regulations for existing power plants. The EPA announced rules on new power plants last year. (See related post: “EPA Makes Historic Announcement: First Greenhouse Gas Rule for New Power Plants.”)

Moniz’s background in science, as opposed to business or government, has also drawn comment. Moniz is a nuclear physicist and head of MIT’s Energy Initiative, and he also served as undersecretary of energy under President Clinton from 1997 to 2001. Some argue that his background in government, which his predecessor Steven Chu did not have, makes him a good candidate. (See related: “Steven Chu to Step Down as Energy Secretary“)

“You can argue about whether you want to have a scientist, but within that food group he’s an excellent choice,” former Massachusetts secretary of energy and environmental affairs Ian Bowles told The Washington Post.

But Jigar Shah, an advocate of solar and partner at the clean energy investment fund Inerjys, has expressed concern that Moniz will not take the action needed to get renewable energy solutions deployed.

“With the latest appointment of Ernest Moniz, President Obama underscores that there will once again be no plan from this administration on oil independence,” Shah wrote at greentechmedia, adding, “Don’t get me wrong; Dr. Moniz is a highly accomplished man. He knows the DOE, especially the nuclear side. So, is that just how like the White House likes it? Appoint a person who will focus on the nuclear weapons side of the job, and focus the DOE on the search for the ‘silver bullet’ through more intensive R&D.”

Moniz’s appointment was met with supportive statements from the Natural Resources Defense Council and the Alliance to Save Energy, and he got a qualified “welcome” from the Sierra Club: “We would stress to Mr. Moniz that an ‘all of the above’ energy policy only means ‘more of the same,’ and we urge him to leave dangerous nuclear energy and toxic fracking behind while focusing on safe, clean energy sources like wind and solar.”

Energy and Natural Resources Committee Chairman Ron Wyden (D-Ore) gave a glimpse of what he might ask Moniz during a confirmation hearing: “I look forward to discussing with Ernest Moniz the many issues before the Energy Department that are so vital to the nation’s energy security. That includes: reengaging Dr. Moniz over the problems with cleaning up nuclear waste at the Hanford Site; finding creative ways to promote new technologies and harness the ingenuity of America’s energy innovators; and examining the diverse opportunities to attack climate change and transition to a low-carbon economy,” Wyden said.

The Hanford Nuclear Facility in Washington State is currently leaking toxic waste from its underground storage tanks. Cleanup is expected to be a multi-decade, multi-billion-dollar effort.