Overhauling crop-climate models for food security

In order to adequately adapt agriculture to a changing climate, scientists need good estimates of how much food we can grow in a warming world. But many of the current crop-climate models are out of date and have significant information gaps.

In a new commentary "Crop-climate models need an overhaul" in the July issue of Nature Climate Change, published online 19 June, 2011, researchers argue for an overhaul of crop-climate models. They point out that many current models do not incorporate the latest knowledge about how crops respond to a changing climate, nor do they represent modern crop varieties and management practices.The CGIAR Climate Program is changing this.

The CCAFS program identified this issue early on, and is taking a number of steps to overhaul crop-climate models:

• We recently published a Report on the Meta-Analysis of Crop Modelling for Climate Change and Food Security Survey which builds understanding on the global extent of crop model development, identifies gaps in capabilities, and determines the geographical coverage and range of crops represented
• We're working on improving understanding of temperature thresholds used in crop models. It's been accepted that changes in both the mean and variability of temperature must be assessed in order to predict the impact of climate change on crop yield. High temperature episodes have a major effect on yield especially when coinciding with flowering, whereas increases in mean temperature have an effect on crop duration. We're investigating temperature thresholds that would be needed to avoid harvests failing under future climate scenarios (i.e. 2030 and beyond).
• Our research program on Adaptation to Progressive Climate Change is using crop models for assessing the impacts of changes in baseline climates on the production of the most important crops within the three CCAFS regions.
• We're also working on a framework for integrating crops and livestock pest and disease analysis with modeling

This work will inform our set of research activities on assessing impacts of progressive climate change on agricultural production and developing appropriate long-term adaptation solutions.