Global fire carbon emissions contribute to increasing atmospheric CO2 concentrations worldwide

Global fires have widespread impacts on the global carbon cycle and atmospheric environment with immediate direct carbon emissions. Fire carbon emission has substantial spatiotemporal variabilities and contributes 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) has 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 March 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 was 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 were large seasonal variations.

Su Mengqian, first author of the 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 can serve as 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 neutrality" policy goals.