Global fire carbon emissions contribute to increasing atmospheric CO2 concentrations

Global fire carbon emissions contribute to increasing atmospheric CO2 concentrations
by Staff Writers
Beijing, China (SPX) Mar 21, 2023

Global fires have widespread impacts on global carbon cycle and atmospheric environment with immediate direct carbon emissions. Fire carbon emission has substantial spatiotemporal variabilities and contributes significantly to the dynamics of global CO2 distributions and variances. Quantifying the impacts of fire carbon emissions on atmospheric CO2 concentrations is the basis for clarifying the carbon cycle in terrestrial ecosystems and a prerequisite for elucidating the carbon balance at global and regional scales.

A research team led by Dr. SHI Yusheng from the Aerospace Information Research Institute (AIR) of the Chinese Academy of Sciences (CAS) quantified the impact of global fire carbon emissions on atmospheric CO2 concentrations through atmospheric transport model simulations, combined with ground-based and satellite observations validation.

The study was published in Science of The Total Environment on Mar. 15.

The research team conducted a series of numerical simulations based on a global atmospheric chemical transport model to quantify the impact of global fire carbon emissions on atmospheric CO2 concentration changes at the grid scale. After validation, the simulation accuracy has been significantly improved (the root mean square error was reduced from 2.403 to 1.980 compared with the satellite observations).

The results showed that the global average annual impact of fire carbon emissions on atmospheric CO2 concentration could reach 2.4 parts per million (ppm), and there are large seasonal variations. For example, Africa contributes to the largest biomass burning emissions worldwide, resulting in a maximum increase of 7.9-13.0 parts per million (ppm) of CO2 concentration in summer.

SU Mengqian, the first author of this study, found that simulation using the Quick Fire Emissions Database (QFED) as the model priori biomass burning emission inventory had the best performance compared with the satellite and surface observations.

The results also showed that the simulated CO2 concentrations were more sensitive to fire carbon emission inventories in southern South America and most areas of the Eurasian continent, and less sensitive in central Africa and Southeast Asia.

"Fire is one of the key factors causing the increase of global atmospheric CO2 concentration and has a significant impact on global warming and climate change", said Dr. Shi.

This study provides a new approach and method to finely quantify the impact of fire carbon emissions on atmospheric CO2 concentration changes, which will provide a scientific basis for biomass burning control.

It also provides guidance for the implementation of environmental policies such as ecological and environmental management and collaborative carbon reduction, which will help China reduce greenhouse gas emission in a more targeted manner and better respond to the "carbon peaking" and "carbon neutral" policy goals.

Research Report:Impacts of different biomass burning emission inventories: Simulations of atmospheric CO2 concentrations based on GEOS-Chem