New projections from the Energy Information Administration find that the trajectory of U.S. greenhouse gas emissions (GHG) is highly sensitive to the operation of the nation's nuclear and coal-fired power plants.
The rate and timing of retirements from these aging plants could dramatically impact how much carbon pollution the U.S. will emit decades from now.
U.S. emissions could be 4 percent higher by 2040 if more nuclear power plants are retired than expected, as natural gas moves in to fill the void. Similarly, if more coal plants are retired than expected, U.S. GHG emissions could be 20 percent lower than expected.
Many of the nation's nuclear plants began operation in the 1960s and 1970s with an initial 40-year operating license – meaning most are near the end of their intended lives.
However, more than 75 percent have received 20-year renewals, which extends their operations into the 2020s and 2030s. Many plant operators are pushing for a second 20-year renewal, and how successful they are at convincing regulators and the public to allow such a move will largely determine how many plants remain in operation beyond the next two decades.
Coal-fired power plants face a darker future. Environmental regulations will most likely lead the industry into gradual decline, forcing many plants out of operation over the same timeframe.
The New York Times has reported on a push by environmental groups to preserve nuclear power in an effort to fight climate change. Backed by former members of Congress and former Obama officials, the Center for Climate and Energy Solutions argues in a new report that nuclear retirements could outpace the construction of renewable energy, resulting in higher net emissions for years. But the group also says that new EPA rules allowing carbon trading could extend the lives of nuclear reactors.