Hotter weather and drier forests are driving bigger wildfires
Wildfires are increasingly affecting air quality and atmospheric composition across multiple regions as fire seasons lengthen.
The assessment was set out in a statement delivered to the World Economic Forum in Davos on 22 January 2026 by Celeste Saulo, Secretary-General of the World Meteorological Organization (WMO).
Observations coordinated by the WMO show that large fires release substantial amounts of fine particulate matter and trace gases detected by Global Atmosphere Watch stations operated by National Meteorological and Hydrological Services and partners.
These emissions include carbon monoxide (CO) and carbon dioxide (CO₂).
Rising fire emissions are associated with record increases in atmospheric CO₂.
Repeated burning is reducing a forest’s capacity to absorb carbon, linking warming, more fires and poorer air quality in a reinforcing cycle.
The statement expressed concern that the Amazon rainforest could be shifting from a major carbon sink towards a net source of emissions.
In 2024, wildfire smoke from the Amazon river basin combined with fires in Chile to affect many countries and densely populated urban areas across Latin America.
Mexico recorded its most active fire season on record in 2024.
Canada burned more than twice its long-term average in 2024 and experienced its second costliest wildfire in history.
US fire activity in 2024 ran around 20% above the 2001 to 2020 average.
Wildfire activity in 2024 coincided with above-average PM2.5 levels in Canada, Siberia and central Africa, with the largest anomaly recorded in the Amazon basin in the WMO Air Quality and Climate Bulletin.
Copernicus Atmosphere Monitoring Service data indicate that Europe experienced its highest annual total fire emissions since records began in 2003 during 2025, with Canada registering its second-highest yearly emissions in the same period.
Weather, satellites and early warning
Saulo outlined how climate and weather extremes are changing fire behaviour and management needs.
Hotter temperatures, prolonged droughts and more frequent heatwaves are drying vegetation and extending fire seasons.
Stronger and more erratic winds are allowing fires to spread faster and cross natural barriers.
Risk varies by region, particularly where forests meet large populations, making practices such as thinning and prescribed burning central to risk reduction.
In remote areas where fires are often ignited by lightning and ground access is limited, satellite monitoring is central to response.
Real-time and long-term fire detection depends on the rapid exchange of satellite data, which the WMO has supported.
In northern Australia, land managers use a satellite-based fire information system developed with the Bureau of Meteorology to track burned areas across vast and inaccessible terrain and to plan fuel management and resource deployment.
After Cyclone Chido in Mayotte in 2024, meteorological analysis identified that dead vegetation would become highly flammable once dry, allowing fire agencies to adjust preparedness in advance.
Seasonal forecasts now provide probabilistic guidance in places such as Réunion and northern Australia, informing decisions on when to conduct prescribed burns, reduce fuel loads and prepare for more intense firefighting.
In France, Météo-France produces a daily meteorological danger map that is translated into a five-level wildfire risk map for each forest area to guide operational decisions.
Regional smoke forecasting centres operate under the WMO Vegetation Fire and Smoke Pollution Warning and Advisory System, including a North American hub hosted by Environment and Climate Change Canada and a Southeast Asian centre in Singapore, providing cross-border smoke forecasts during severe fire seasons.
Saulo said: “In the next five years, we must stop treating wildfires as surprises and start managing forests as critical infrastructure, using science, early warning, AI and strong partnerships to act early, protect people from smoke and heat, and ensure forests reduce risk rather than fuel the next crisis.”