Climate Change: Ground Zero by UNEP Robert Ondhowe, United Nations Environmental Programme
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limate change is transforming how society lives and interacts with nature. Its effects are most readily evident and felt in food security, with land resources playing a major role because of the sizeable global population that still relies on rain-fed and subsistence agriculture. Most African economies, unlike much of the rest of the world, largely depend on land-based economic activities, especially agriculture. Thus, land management strategies that can assist farmers in dealing with changing climatic patterns are critical for food security. Since 1880, the Earth’s average surface temperature has increased by 1.5°F (0.83°C). However, the effect of climate on agriculture is associated more with the variability of local climate than to the global climate patterns. The United Nations Environmental Programme (UNEP), in Livelihood Security: Climate Change, Conflict and Migration (2011), observes that, from 1970 to 2006, changes in the seasonal temperatures in the Sahel region of Africa have risen by a range of between 0.5 to 2.0°C. The impact is such that United Nations Secretary-General’s Special Advisor on Conflict, Jan Egeland, referred to the Sahel region of Africa as the “ground zero” of climate change. Despite technological advances such as improved crop varieties, genetically modified seed and irrigation systems, the weather is still a key factor in Africa’s agricultural productivity, as are its very fragile soil properties and communities. A study published in Science magazine suggests that, due to climate change, “southern Africa could lose more than 30 percent of its main crop,
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UNCCD . World Bank
maize, by 2030. In South Asia, losses of many regional staples, such as rice, millet and maize could top 10 percent.17” Globally, in many rain-fed, nonirrigated areas, crops are already near their maximum temperature tolerance due to rising temperatures. Yields are also likely to fall sharply from even small climate changes. The poorest countries will be hardest hit, with reductions in crop yields in most tropical and subtropical regions caused by decreased water availability and new or changed insect/pest incidences. Experts project a fall in agricultural productivity of up to 30 percent during the 21st century, but the effects of climate change on crops are expected to vary from region to region. Tanzania’s official report on climate change suggests that the areas that usually get two rainfalls in a year will probably get more, and those that get only one rainy season will get far less. The net result expected is that 33 percent less maize—the country’s staple crop—will be grown. Overall, the average crop yield is expected to drop in areas where there is decreased rainfall, whereas cereal production could actually increase in places of increased rainfall, if managed properly. For the favorable effects on yield to happen, much will depend on the realization of the potentially beneficial effects of carbon dioxide on crop growth and an increase in efficient water use. Stated differently, while adaptation is linked to efficient water use, the health of the land will matter for resilience, with regard to producing more organic carbon and increasing groundwater recharge.
