Wetter isn't better: global warming and food security in the Congo Basin

Over 20 million forest farmers practice slash and burn agriculture in the forests of the Congo Basin (Bahuchet and de Maret, 1995. State of Indigenous Populations Living in Rainforest Areas, European Commission DG XI Environment, Brussels). They rely on the long dry season (December-February north of the equator) to ensure that their new fields, cleared from regrowth forest, burn sufficiently well to deposit nutrients into the soil and to minimize the labor required to prepare the field for planting. Data from the Ituri forest in northeastern Democratic Republic of Congo show that the strength of the annual dry season (a) has a direct positive impact on the size of fields cleared each year by slash and burn farmers, and consequently on food production and the severity of the subsequent year's pre-harvest hunger period; and (b) is inversely related to total annual rainfall. These results suggest that the 1 mm/d increase in rainfall predicted for much of the Congo Basin by the 2050s may cause a basin wide increase in the frequency of heavy rains during the dry season, causing a reduction in the size of slash and burn farmers' fields, and potentially a substantial increase in the food insecurity of poor rural families across the region. (C) 1999 Elsevier Science Ltd. All rights reserved.