Smoke from rampant peatland wildfires fueled by a record-breaking El Niño has engulfed Indonesia and much of Southeast Asia in a toxic haze. As the blazes diminish air quality by releasing hazardous pollutants, they are also emitting massive amounts of planet-warming carbon.

So far this year, Indonesia’s fires have released an estimated 190 million tons of carbon. That’s roughly equivalent to three-quarters of the country’s annual CO2 emissions from burning fossil fuels, according to Earth scientists Gareth Roberts and Martin Wooster. In an article for The Conversation, they explain how El Niño-driven drought set the stage for the current crisis.

Parched conditions are exacerbating the flammability of peatlands that were already degraded by deforestation and drainage, making it easier for fires to spark and spread, they write. When peat ignites, it can smolder underground for weeks or months, releasing ancient carbon that had been locked away for centuries.…