They found that the lost nuclear electricity production due to the phase-out was replaced primarily by coal-fired production and net electricity imports. The social cost of this shift from nuclear to coal is approximately 12 billion dollars per year. Over 70% of this cost comes from the increased mortality risk associated with exposure to the local air pollution emitted when burning fossil fuels. Even the largest estimates of the reduction in the costs associated with nuclear accident risk and waste disposal due to the phase-out are far smaller than 12 billion dollars.
There was an additional 36 million tons of carbon dioxide per year, or about a 5 percent increase in emissions. Burning more coal led to local increases in particle pollution and sulfur dioxide and likely killed an additional 1,100 people per year from respiratory or cardiovascular illnesses.