President Obama announced in a White House ceremony on Monday his nominees to head the Environmental Protection Agency, the U.S. Department of Energy, and the Office of Management and Budget (OMB).

Gina McCarthy, a 25-year veteran of environmental policy and politics was nominated to head up EPA and has served under both Republicans and Democrats.  She has worked at both the state and local levels on critical environmental issues and currently is assistant administrator for EPA’s Office of Air and Radiation.  Prior to her confirmation in that position in 2009, McCarthy served as the administrator of the Connecticut Department of Environmental Protection from 2004-2009; deputy secretary of operations, Massachusetts Office of Commonwealth Development, 2003-2004; and assistant secretary of pollution prevention, Environmental Business and Technology for Massachusetts, 1999-2003. She is known for her matter-of-fact approach.

During her tenure at EPA, she has prominently defended EPA policies and is a crucial player of the Obama administration’s plans to reduce emissions believed to cause climate change.  She was behind many of the agency’s most controversial new rules, including placing limits on greenhouse gases on newly built power plants to the first-ever standard for toxic mercury pollution from burning coal for electricity.

MIT scientist Ernest Moniz was nominated to head the Energy Department.   He oversees MIT’s Energy Initiative, a research group that focuses on innovative ways to produce power while curbing greenhouse gas emissions.  He is well-versed in the ways of Washington as he served as the undersecretary at the Energy Department in the Clinton administration where he learned to balance both political and scientific demands.  “Physics sometimes looked easy compared to doing the people’s business,” he said in an interview.  He has advised President Obama on the administration’s energy plan, including retooling of the country’s stalled nuclear waste program, energy research and development, and unconventional gas.

OMB nominee Sylvia Mathews Burwell, another Washington veteran, served in several posts during the Clinton administration, including OMB deputy director.  She currently heads the Wal-Mart Foundation, the philanthropic arm of the retail giant.  She was previously president of the Gates Foundation’s Global Development Program.  If confirmed, she will be a key player in Washington’s fiscal fights.

All three nominees must be confirmed by the Senate.