Haze from stubble burning over north India captured in a satellite image. Credit: NASA EOSDIS LANCE and GIBS/Worldview.
Every winter, farmers across northwestern India burn leftover rice stubble to clear fields for wheat. A new study confirms what scientists had long suspected but never firmly proven — these fires are heating the land.
Researchers at Banaras Hindu University analyzed five years of satellite data (2017–2021) over the region’s fire hotspots1. Using a combination of spatial correlation, space-for-time comparisons, Random Forest models, and geographically weighted regression, they teased out the thermal effect of fires from the noise of weather and terrain.
Their findings show that, on average, crop burning raises land surface temperatures by about 0.6 °C in heavily affected areas. Fires also pump more smoke into the air, and the larger the fire, the greater the local heating. Weather conditions further amplify the effect: a shallow planetary boundary layer, averaging 71 metres, traps heat and smoke near the ground, intensifying warming. Impacts vary year to year depending on fire intensity and atmospheric conditions.
Beyond worsening air quality in Delhi, these seasonal fires represent a measurable climate perturbation. Current Earth system models underestimate this effect, meaning that more precise accounting could improve climate projections and guide smarter agricultural policies, the authors suggest.
