CHAPTER 5: Cooling the Earth with Crops

Food security and climate change are two of the biggest challenges which face humanity in the 21^st Century and agricultural land is the physical interface for these interlinked issues. This chapter addresses how cropland interacts with climate; the ways in which crops have affected climate in the past; and how crops could help mitigate climate change in the future. Of the ways that climate issues and crops are related, one of the most relevant to the future is through geoengineering. The concept of deliberately using crops to reduce the surface air temperature is still in development, but has gathered considerable interest in recent years. Models suggest that in North America and Europe, a moderate increase in crop albedo could decrease summertime temperatures by up to 1 °C. Although this amounts to a small change compared with many other geoengineering proposals, it could be made with relatively little cost and would make a significant difference to crops which are particularly sensitive to high temperatures, such as wheat. Along with other climate mitigation strategies, cooling with crops could be one aspect of a deliberate policy to limit the dangerous impacts of climate change.