Projected temperature increases may require shifts in the growing season of cool-season crops and the growing locations of warm-season crops

Authors: MARKLEIN, ALISON - Lawrence Berkeley National Laboratory; Elias, Emile; NICO, PETER - Lawrence Berkeley National Laboratory; Steenwerth, Kerri

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/10/2020
Publication Date: 7/18/2020
Citation: Marklein, A., Elias, E.H., Nico, P., Steenwerth, K.L. 2020. Projected temperature increases may require shifts in the growing season of cool-season crops and the growing locations of warm-season crops. Science of the Total Environment. 746. https://doi.org/10.1016/j.scitotenv.2020.140918.
DOI: https://doi.org/10.1016/j.scitotenv.2020.140918

Interpretive Summary:

Technical Abstract: The diverse range of Mediterranean climatic conditions in California supports a notably high crop diversity and production, yet California also faces greater frequency of extreme weather events indicative of a changing climate. Therefore, predicting the effects of climate change on where and when crops can be grown is critical for maintaining the amount and diversity of produce grown by this state. Determining the effect of temperature is a crucial first step because it is more likely than CO2 to have a negative effect on yields and more difficult to mitigate than changes in precipitation. Here, we compared the temperature constraints under climate projections for five annual crops that contribute largely to food security among food banks in California. We first determined historical monthly temperature and projections of maximum and minimum monthly temperature for the mid-21st century based on four climate projections (two climate models × two climate change scenarios). We then determined where temperatures were suitable for each crop historically and in the future at two spatial scales (4km grid-cell and statewide) and two temporal scales (monthly and for each respective crop’s growing season). We found differences between the warm- and cool-season crops: temperature affects when cool-season crops (broccoli; lettuce) could be grown more than where they could be grown, but temperature affects where warm-season crops (cantaloupe; tomato; carrots) could be grown more than when they could be grown. Integration of our results with other factors that affect crops – including management, breeding, and precipitation changes – provides guidance for adapting California agriculture to climate change.