As the climate warms, wildfires are becoming more frequent. Parts of Southern Europe, such as Spain and Greece, have already seen their first wildfires of the season, with devastating impacts on local ecosystems and biodiversity. Wildfires, however, also have major impacts on global and regional atmospheric chemistry, climate, and air quality and health. Emissions of air pollutants and greenhouse gases, and their long-distance transport can also impact people and ecosystems further away. New York City, for instance, recorded its worst air quality in recent history in June 2023 following massive wildfires in Canada.
As fire frequency and intensity increase and its location changes, modelling these fires and their impacts is becoming increasingly critical to policy responses. At the same time, fire modelling bears many uncertainties, which is why preparations are underway for a multi-model, multi-pollutant, multi-regional study will be carried out under the auspices of the UNECE Air Convention’s Task Force on Hemispheric Transport of Air Pollution. Expected to be launched later this year, the 3-5 year study will bring together the multi-disciplinary, international atmospheric modeling and fire science communities to work towards the common goal of improving quantitative estimates of the air pollution and climate impacts of fires.
Fire emissions can include persistent organic pollutants, heavy metals, particulate matter, tropospheric ozone precursors, like nitrogen oxides, volatile organic compounds and carbon monoxide, and greenhouse gases like methane and carbon dioxide. While contributions to bad air from industry and transport are decreasing in many parts of the world as a result of emission controls, the contribution of fires to air pollution episodes is growing.
The fires study is one of three multi-model global atmospheric modeling studies that have been launched or will be launched by the Task Force in 2024. The plans and progress for each of the three studies were discussed at the annual meeting of the Task Force (22-25 April 2024). The studies will contribute to understanding the relative contribution of anthropogenic and natural sources to air pollution impacts on health, ecosystems, and climate at the regional to global scale. The results of the studies will help inform the revision of the Air Convention’s Gothenburg Protocol, as amended in 2012.