The Indian state of Punjab has two growing seasons: one from May to September and another from November to April. Many farmers rotate between crops, planting rice in May and wheat in November. In order to quickly prepare their fields for the wheat crop, many farmers simply burn leftover plant debris after harvesting rice. The practice is known as paddy stubble burning.
Every year, Punjab rice farms collectively burn about 7 to 8 million metric tons of leftover plant debris in October and November. When the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite passed over Punjab on October 30, 2014, numerous fires were burning. Red outlines show the approximate locations of active burning.