RICHMOND HILL, ON, Canada, June 12, 2025 – An explosive start to Canada’s wildfire season, which has already burned over 2.7 million hectares and forced more than 33,000 people from their homes, is a stark manifestation of a warming climate, according to a new publication by the United Nations University Institute for Water, Environment and Health (UNU-INWEH). The analysis highlights the cascading national and international impacts, with smoke plumes affecting over 117 million people in the United States, signaling an urgent need for a new approach to wildfire management and international cooperation.
The UNU-INWEH Incident Brief, “The 2025 Central Canada Fires as of June 8: National Challenges of a Warming Climate and Cascading International Impacts,” analyzes the devastating fires that have raged across central Canada since mid-May. Driven by a warm, dry winter and spring, with temperatures more than 2.5°C above average, the fires have led to states of emergency in Manitoba and Saskatchewan and created a significant air quality crisis across North America.
“What we are witnessing is not just a series of isolated incidents, but a glimpse into a new, fire-prone reality shaped by human activities and climate change,” said Professor Kaveh Madani, Director of UNU-INWEH. “The scale of these fires and their transboundary impacts are a wake-up call. We must recognize this as the increasing trend of large-scale burning in Canada requires a fundamental shift in our preparedness, response, and, most critically, our global commitment to deal with climate change.”
Key findings from the analysis reveal the staggering scope of the crisis. The season's explosive scale has seen over 2.7 million hectares burned by June 8, 150 times larger in area than the 2025 Los Angeles fires. The fires led to massive social disruption with more than 33,000 people evacuated including the entire community of Flin Flon, Manitoba and tragically, two civilian fatalities. The unprecedented smoke impact demonstrates the profound international reach of these disasters; on a single day, smoke plumes exposed over 117 million people in the United States and 2 million in Canada to heavy smoke. The report clearly links the fire's intensity to the fingerprints of climate change, which is lengthening fire seasons and amplifying the dry and extreme weather conditions that fuel more intense wildfire behavior.
The fires have disproportionately affected remote and Indigenous communities, highlighting vulnerabilities in infrastructure and evacuation capabilities. Limited roads, reliance on air evacuation, and the potential for critical infrastructure like power and communications to fail create cascading risks.
"Our findings highlight the growing wildfire-related challenges facing northern, mesic ecosystems, which not only strain the critical infrastructure in these increasingly vulnerable regions but also produce smoke that travels thousands of kilometers over weeks, affecting hundreds of millions of people across international borders." said Dr. Mojtaba Sadegh, the Climate and Wildfire Analytics Lead at UNU-INWEH who led the study.
The UNU-INWEH publication calls for urgent action on several fronts, emphasizing the need to enhance societal preparedness through the widespread adoption of home and infrastructure hardening principles like FireSmart, alongside improved evacuation systems and robust support for displaced populations. This includes investing in resilience by designing fire-resistant critical infrastructure and establishing community wildfire shelters, especially in remote regions.
Furthermore, the study team stress the importance of strengthening international cooperation to share firefighting resources and expertise across borders, which is crucial for managing peak disaster periods more effectively. Finally, protecting public health is paramount, requiring increased awareness of smoke-related health risks and the creation of clean air shelters and other protective measures for vulnerable populations.
The report concludes that curbing global temperature increases is the ultimate tool for mitigating the escalating risk of wildfires, particularly in the vital, carbon-rich ecosystems of the world’s boreal forests.
Read the Paper
Seydi S. T., Abatzoglou J. T., AghaKouchak A., Madani, Matin, M., K. Sadegh M., (2025), The 2025 Central Canada Fires as of June 8: National Challenges of a Warming Climate and Cascading International Impacts, United Nations University Institute for Water, Environment and Health (UNU-INWEH), Richmond Hill, Ontario, Canada. doi: https://doi.org/10.53328/INR25MOS004
The UNU research team is available for interviews:
Dr. Mojtaba Sadegh, Lead, Climate and Wildfire Analytics, mojtaba.sadegh@unu.edu
Dr. Mir Matin, Manager, Geospatial, Climate and Infrastructure Analytics Program, mir.matin@unu.edu
Professor Kaveh Madani, Director, kaveh.madani@unu.edu
Media Contacts
Shooka Bidarian, Media and Journalism Fellow, Sustainability and Climate, shooka.bidarian@unu.edu
Kyra Bowman, UNU Head of Communications, bowman@unu.edu
