Climate change and locusts in the WANA region

Abstract

The Desert Locust is probably the oldest and most feared migratory pest in the world, plaguing farmers in Africa and Asia since Phaoronic times. Under optimal conditions, locusts increase rapidly and form swarms. A single swarm, larger than Paris or Cairo, can contain billions of insects, migrate across continents, and eat enough food for 2,500 people in 1 day. During plagues, vulnerable households can find themselves in debt, limited national resources are rapidly depleted and food security can be at risk in affected countries. It can take several years and hundreds of millions of dollars to bring a plague to an end. Changes in the climate during the remainder of this century will affect Desert Locust habitats, breeding, migration and plague dynamics in West Asia and North Africa (WANA). Although it is widely acknowledged that WANA will become warmer, there are differing views about changes in precipitation under the various climate change scenarios. General trends may contain hidden variations within the regions and countries. Certain areas will become more prone to extreme events such as flooding and droughts. Regular assessment of climate change impacts is a component of the locust early warning system operated by the Food and Agriculture Organization (FAO) of the United Nations to monitor the global situation and alert locust-affected countries and international donors. The latest scientific evidence is reviewed to postulate potential effects on the Desert Locust. It is probably reasonable to assume that this ancient pest, which is particularly well suited for survival under difficult conditions in arid areas and has successfully endured previous changes in the climate, will adapt to climate variability in the foreseeable future.