Why is crop modelling comparison so important for food security?

By Hannah Rowlands

We were fortunate enough to have Professor James Jones, University of Florida, one of the principal investigators on AgMIP, speak to us recently in Oxford about "Model-Based Integrated Assessment of Food Security".

AgMIP, the Agricultural Modelling Intercomparison and Improvement Project, is an unprecedented international collaboration between crop and economic modellers from around the world. The project has been working with over 20 crop models and 10 global agro-economic models to compare the results from each and to take median results across all of them to get new regional and global results.

Professor Jones explained that  we need more agricultural modelling to understand better the interactions between economics, crops and climate change. However, many different models and scenarios can be used used, so if we dont compare results across studies we can’t know the uncertainty of individual results. Previous research has produced wide variations in results concerning the future of food prices, production, and trade.

This is where AgMIP comes in. As a first step, all the major existing crop models are compared, at a regional and global level, to see how different assumptions in each lead to different results in, say, future production of maize.

But an even more interesting result occurs when you take the median from all the models for a particular outcome: what the modellers found was that the median of crop model ensembles was better across all locations than any single model.

This is an important result, as it emphasises the usefulness of this intercomparison exercise, and indicates that better, more accurate agricultural models could provide us with more information about how climate change will affect agricultural production in the future. This also helps to quantify uncertainty, which is a particular issue when looking at how crops respond to climate change.

Professor Jones’s closing remark was that AgMIP is a platform for collaboration across disciplines and across the globe, which is producing new science results for crop and economic modelling, and that there is great potential for more advances in this area.

Crop modelling intercomparison is important if you want to tackle the challenge of food security because it contributes substantially to our understanding of world food supply and provides the information needed to improve people’s ability to adapt to climate change in both developing and developed countries.

Listen to Professor James Jones's talk about download his slides from the Video & Audio page on the website.

Photo of maize agriculture in South Africa by Wolf Avni, Shutterstock.

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