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As 195 countries adopted the first-ever universal, legally binding global climate deal in December 2015, IWMI published a book examining the impacts of future climate shifts on water use in agriculture. Published by CABI, Climate change and agricultural water management in developing countries was edited by IWMI’s Chu Thai Hoanh (Emeritus Scientist), Vladimir Smakhtin (leader for IWMI’s research theme on Water Availability, Risk and Resilience) and Robyn Johnston (IWMI’s Myanmar Representative), and included contributions from 10 IWMI researchers, along with35 collaborators from 15 external organizations.
With 70% of freshwater resources used in farming, and demand for
food expected to double over the next 50 years, the impacts of
climate change on rainfall, river flows and groundwater levels will
translate into impacts on agricultural production. The book analyzed
the projected impacts of climate change on water used for agriculture
at a global level, assessed in detail the effects on farming in particular
countries and regions, and examined existing water management
options for adapting to those changes. It also considered the impact
of sea-level rise on agriculture.
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“We wanted to provide advice for agriculture and irrigation planners,
decision makers, researchers and students,” said Hoanh. “So, in
addition to global overviews, we included case studies showing
detailed crop water requirements and agricultural adaptation options, such as water-saving techniques and groundwater exploitation. Findings and conclusions from the studies presented in the book may help to identify potential actions to take and subjects for further research.”
The book showed that the amount of land suitable for farming is set to decrease, with some models predicting the area currently deemed highly suitable for crops likely to shrink by a fifth. Terrain classified as ‘marginally suitable’ or ‘moderately suitable’ for agriculture is forecast to expand. “By the 2050s, the area of land subject to increasing water stress is projected to be more than double that with decreasing water stress,” explained Smakhtin. “In particular, the frequency of short droughts is likely to increase in presently dry regions.”
The authors found that, overall, the negative impacts of future climate change on freshwater resources are likely to outweigh the benefits, with the world’s poorest people likely to feel the impacts most keenly unless action is taken. However, the book presented some cause for optimism. Although warmer temperatures are likely to demand more water for irrigation, and competition for water from industrial and domestic uses is set to increase, improving agricultural water management and liberalizing the global food trade should enable us to meet future food demands.
