From NASA’s Earth Observatory website:
Season after season, year after year, people set fire to African landscapes to create and maintain farmland and grazing areas. People use fire to keep less desirable plants from invading crop or rangeland, to drive grazing animals away from areas more desirable for farming, to remove crop stubble and return nutrients to the soil, and to convert natural ecosystems to agricultural land. The burning area shifts from north to south over the course of the year, in step with the coming and going of Africa’s rainy and dry seasons.
NASA has previously published some impressive seasonal fire patterns of the African continent, using Terra and Aqua satellite telemetry data. More recently, the University of Maryland, in partnership with NASA and the UN Food and Agriculture Organization, has created the Fire Information for Resource Management System (FIRMS). FIRMS combines remote sensing and GIS technologies to deliver near real-time global hotspot/active fire locations to natural resource managers and other stakeholders around the world. Here’s a dynamic map of Africa’s bush fires plotted over the last 48 hours:
As you can see, the most intense fire activity is located around Angola, southern DRC, Zambia, Mozambique and Madagascar. This is consistent with seasonal fire patterns for this time of year.
While fire is a part of the natural cycle of the seasonally dry grasslands and savannas of Africa, ecologists and climatologists have reason to be concerned about Africa’s intense burning. The frequency with which fires return to previously burned areas helps determine which species of plants (and therefore animals) can survive. When the fire-return interval is too quick, the land may become degraded and unusable for farming or grazing. In the semi-arid and fragile Sahel, land degradation through overuse of fire or overgrazing can create pockets of desert. The massive amount of burning that occurs in Africa each year creates carbon dioxide and aerosol particles, both of which play a role in global climate and may create a public health hazard as well (as one who has lived through many of Central West Africa’s fire seasons, I can attest to the latter).
Seasonal burning of dry grassland and savanna is one issue, but slash and burn agriculture of Africa’s forestland is a different matter. Near real-time mapping resources such as FIRMS are invaluable tools for advocacy, outreach and community education.
For more information about this topic, check out blogger Andriankoto Ratozamanana’s TED Global talk on the environmental crisis posed by the “crazy slash and burn” of Madagascar’s forests and the positive steps being taken to remedy the problem.