Climate Change, Agriculture and Food Security
What are the implications of climate change for agriculture? Can climate models be used to make agricultural decisions? This study investigated the ability of climate models to reproduce observed climates (in particular conditions important for crop growth), projections of how crops might grow under future conditions, and the reliability of future climate projections. The report was produced by Oxford for the CGIAR (Consultative Group for International Agricultural Research) and focused on three regions: East Africa, West Africa and the Indo-Gangetic plains. Key findings pertaining to the African regions are listed below. The full report can be found here.
- Climate models are generally able to simulate temperatures adequately, although many exhibited a slight cool bias, including the ensemble
- Precipitation is less well represented, and model biases are greater than for temperature
- Pigeon pea may have significantly greater potential for development in the region than is currently the case, if cultivation is not restricted by other factors
- Under anthropogenic climate change projections, a warmer and wetter future is predicted, with good agreement between models
- Some crops such as bananas, cassava, pigeon pea and rice may see an expansion of optimally suitable areas as a result of relatively high temperatures being optimal for their growth. In contrast, crops with cooler optimal thresholds such as maize, millet, potato, sorghum, sweet potato and wheat may be less suited to a warmer climate, and higher temperatures may adversely affect yields
- Temperature climatologies, variability and trends are generally robustly reproduced by climate models.
- The models do not perform as adequately in their simulation of regional precipitation patterns, with biases in the model climatologies, uncertainty in the reproduction of trends, and under-estimation of climatic variability
- Model projections of the future in the region are highly uncertain. Temperature trends, including extreme indices, are all positive, though the models vary in the magnitude of the projected increases
- Precipitation projections vary from significant decreases in precipitation and extended droughts to to increases in precipitation and decreased frequency and length of droughts
- The outlook for agriculture is highly uncertain, particularly in the vulnerable Sahel region
Note – the report was published in February 2012.
Prof Richard Washington
Dr Matt Hawcroft
Dr Helen Pearce