Japanese carbon emissions patterns shifted following the 2008 financial crisis and the 2011 Tohoku earthquake

Unexpected events such as economic crises and natural disasters can have profound implications for energy systems and climate change mitigation efforts at different levels. Here we explore the national and regional carbon emission patterns (and their drivers) for the main economic sectors in Japan between 2007 and 2015, a period shaped by the 2008 financial crisis and the 2011 Tohoku Earthquake. Following the 2011 earthquake the previously decreasing regional emissions patterns started increasing in practically all regions except Hokkaido. This was mainly due to growing coal use particularly in the Kyushu, Chugoku and Kansai regions. Furthermore, most regions experienced shifts in the dominance of different drivers of emissions over time, with a stronger initial impact from economic effects after the 2008 financial crisis, followed by energy structure after the 2011 earthquake, and then by economic effects and energy intensity. These results offer a more nuanced understanding of how individual events can affect emissions at different periods and levels (national vs. regional) to inform the design of climate change mitigation strategies. Exogenous events in Japan had lasting impacts on the energy mix and on CO2 emissions at the national and regional levels. The 2008 financial crisis mainly affected the economy, whereas the 2011 earthquake influenced energy structure, though the actual impacts vary between regions.