Estimates of carbon emissions from forest fires in Japan, 1979–2008

Abstract

Emissions from forest fires directly affect the global and regional carbon cycles by increasing atmospheric carbon as well as affecting carbon sequestration by forests. We have estimated the release of total carbon, carbon-based trace gases (CO2, CO, CH4) and non-methane hydrocarbons (NMHC) emitted from forest fires in Japan during a 30-year period from 1979 through 2008. The area burnt varied widely from year to year but has gradually diminished since the 1980s. The mean annual area burnt during the period was 1878 ha. The mean annual estimate of direct carbon emissions from forest fires in Japan was 15.8 Gg C year–1 and ranged between 2.7 and 60.4 Gg C year–1. The mean annual trace gas emissions were 49.4 Gg CO2 year–1, 3.4 Gg CO year–1, 0.15 Gg CH4 year–1 and 0.18 Gg NMHC year–1. Although the carbon emissions varied widely from year to year based on the area burnt, they decreased dramatically from the 1980s onward. The interannual variations in trace gases parallel the total carbon emissions. The direct emissions from forest fires in Japan were substantially lower compared with the mean annual net primary production of Japanese forests or the carbon release in other countries and regions. However, the average annual carbon released per unit area burnt was comparable to that estimated in other regions and rose gradually with the increasing age of plantations.