Effects of nuclear power plant shutdowns on electricity consumption and greenhouse gas emissions after the Tohoku Earthquake

This study analyzes how the substitution of fossil fuels for nuclear power due to the shutdown of nuclear power plants after the Tohoku Earthquake affects electricity consumption and greenhouse gas emissions in Japan. Results indicate that Japan generated 4.3 million metric tons (or 0.3%, with a 95% confidence interval) of additional CO₂ emissions in 2011 following the earthquake. The increase in CO₂ emissions stemmed from the combined effects of decreased electricity consumption due to energy conservation efforts and the substitution of fossil fuels for nuclear power following the Tohoku Earthquake. Results also show considerable spatial variation in the impacts of the earthquake on net CO₂ emissions. A majority of the prefectures (40 of 47 prefectures, or 85%) were predicted to experience higher CO₂ emissions after the Tohoku Earthquake while the remaining (7 prefectures) were predicted to experience lower CO₂ emissions. Our findings suggest that Japan and countries under similar risks may want to reformulate energy policy by emphasizing utilization of diverse power and energy sources, including more renewable energy production and electricity conservation. The policy reform should also consider spatial variation in the combined effects of reduced reliance on nuclear power and increased CO₂ conversion factors.