File:Fires in Ethopia and South Sudan (MODIS 2021-02-09).jpg

English: Many dozens of fires were burning across Ethiopia and South Sudan on February 8, 2021 when the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of the region. Each red “hot spot” marks an area where the thermal bands on the instrument detected temperatures higher than background. When combined with typical smoke—as in this image—such hot spots mark actively burning fires.

These fires are part of a long band of fire that stretches across the African continent, from Senegal to Eritrea. Such fires follow a pattern: after seasonal rains diminish in November, fires begin to increase across Africa especially in the Sahel region. The numbers of fires increase slowly, typically increasing in number sometime in January. In March, the fires begin to diminish as the rains return.

These seasonal fires are primarily agricultural blazes—fires that are deliberately set to manage land. Agricultural fires serve a variety of purposes. It is often used to open new savanna, grassland, or forest into cropland or pasture. In established fields, fire is an easy tool used to clear stubble and waste at the end of a growing season and to return nutrients to the soil. Pastureland is sometimes renewed by burning, as it clears the field of unwanted weeds and encourages fresh growth of forage.

While fire is a commonly used tool in traditional agriculture, it can produce tremendous amounts of smoke that can harm the health of both human and animals. Fire may also slip out of control to create wildfire that may damage large areas. Widespread use of fire in “slash-and-burn” practices is a major factor in deforestation across the Earth.