The study shows that as the world warms, climate change is likely to cause more and bigger wildfires in many regions, especially at higher latitudes. These fires release tiny particles that contain soluble iron, a nutrient that ocean life can use. Winds carry those particles over the ocean, and when they finally settle into the water, the added iron can act like a fertilizer for microscopic plants known as phytoplankton. In parts of the ocean—such as the North Atlantic—iron is usually in short supply, so this extra nutrient can help phytoplankton grow more. More phytoplankton means more carbon dioxide can be pulled out of the atmosphere because these organisms absorb CO₂ through photosynthesis, linking fires on land with changes in sea life and the global carbon cycle.
Using advanced climate and Earth system models, we found that by the end of the century climate-driven fires could increase iron emissions from fires by about 1.7–1.8 times compared with current projections that don’t account for changes in climate. In the iron-limited North Atlantic, this could boost ocean productivity due to deposited soluble iron by up to 20 % over the year and even 40 % during summer if other nutrients remain stable. However, warming oceans may reduce the availability of some other nutrients, so the actual changes in productivity will depend on several interacting factors. The study highlights the connection between wildfires, atmospheric particles, and ocean ecosystems, showing how changes on land can ripple across the planet’s systems.
