Agricultural production


A significant effect of global climate change is the altering of global rainfall patterns, with certain effects on agriculture.[60] Rainfed agriculture constitutes 80% of global agriculture. Many of the 852 million poor people in the world live in parts of Asia and Africa that depend on rainfall to cultivate food crops. As the global population swells, more food will be needed, but climate variability is likely to make successful farming more difficult. Extended drought can cause the failure of small and marginal farms with resultant economic, political and social disruption. However, such events have previously occurred in human history independent of global climate change. In recent decades, global trade has created distribution networks capable of delivering surplus food to where it is needed, thus reducing local impact (Jennings 2008).
Drought tolerant crop varieties
Agriculture of any kind is strongly influenced by the availability of water. Climate change will modify rainfall, evaporation, runoff, and soil moisture storage. Changes in total seasonal precipitation or in its pattern of variability are both important. The occurrence of moisture stress during flowering, pollination, and grain-filling is harmful to most crops and particularly so to corn, soybeans, and wheat. Increased evaporation from the soil and accelerated transpiration in the plants themselves will cause moisture stress. As a result, there will be a need to develop crop varieties with greater drought tolerance.
More spending on irrigation
The demand for water for irrigation is projected to rise in a warmer climate, bringing increased competition between agriculture—already the largest consumer of water resources in semi-arid regions—and urban as well as industrial users. Falling water tables and the resulting increase in the energy needed to pump water will make the practice of irrigation more expensive, particularly when with drier conditions more water will be required per acre. Other strategies will be needed to make the most efficient use of water resources. For example, the International Water Management Institute has suggested five strategies that could help Asia feed its growing population in light of climate change. These are:
- Modernising existing irrigation schemes to suit modern methods of farming.
- Supporting farmer's efforts to find their own water supplies, by tapping into groundwater in a sustainable way.
- Looking beyond conventional 'Participatory Irrigation Management' schemes, by engaging the private sector.
- Expanding capacity and knowledge.
- Investing outside the irrigation sector (Mukherji 2009).
Rainwater storage
Providing farmers with access to a range of water stores could help them overcome dry spells that would otherwise cause their crops to fail. Field studies have shown the effectiveness of small-scale water storage. For example, according to the International Water Management Institute, using small planting basins to 'harvest' water in Zimbabwe has been shown to boost maize yields, whether rainfall is abundant or scarce. And in Niger, they have led to three or fourfold increases in millet yields (Diverse… 2010).
Jennings, P. A. (February 2008). "Dealing with Climate Change at the Local Level" (PDF). Chemical Engineering Progress (American Institute of Chemical Engineers) 104 (2): 40–44. Retrieved 2008-02-29.
Mukherji, A. Revitalising Asia’s Irrigation: To sustainably meet tomorrow’s food needs 2009, IWMI and FAO.
Diverse water sources key to food security: report, Reuters, September 5, 2010.