Historical Simulation and Future Projection of Arctic-Boreal Fire Carbon Emissions and Related Surface Climate by 17 CMIP6 ESMs

Abstract

Wildfire is a crucial factor in influencing the earth system. Wildfire activities in the Arctic-boreal region have received increasing attention particularly with increasing frequency and intensity under rapid climate warming in recent years. In this study, the historical simulation and future projection of the Arctic-boreal fire carbon emissions and associated surface climate conditions (surface air temperature and precipitation) are examined using 17 CMIP6 Earth System Models. For the historical period, more than half (11 out of 17) of the models underestimate ∼40% of the observed annual mean fire carbon emissions in the Arctic-boreal region (0.20 PgC/yr) due to a wetter bias in the Arctic-boreal regions. Spatially, there is common underestimation of the fire centers in the eastern part of Eurasian Continent and overestimation of that in Europe. With respect to the model spread, it mainly shows large spread for fire carbon emissions (surface air temperature) in Europe (high-latitudes). For the future projection, the fire carbon emissions in the Arctic-boreal region is projected to exceed 100% (0.5 PgC/yr until the end of the 21st century compared with ∼0.2 PgC/yr at present). The projected precipitation and temperature in the Arctic-boreal region land also show an upward trend during the 21st century (∼31% for annual mean precipitation and ∼10°C for surface air temperature). There are considerable bias and intra-model spread among different models in both historical simulation and future projection.