Atmospheric Environment, 45(13) (April 2011); DOI: 10.1016/j.atmosenv.2010.11.045

Global crop yield reductions due to surface ozone exposure: 1. Year 2000 crop production losses and economic damage

Shiri Avnery, Denise L. Mauzerall, Junfeng Liu and Larry W. Horowitz

Abstract

Exposure to elevated concentrations of surface ozone (O₃) causes substantial reductions in the agricultural yields of many crops. As emissions of O₃ precursors rise in many parts of the world over the next few decades, yield reductions from O₃ exposure appear likely to increase the challenges of feeding a global population projected to grow from 6 to 9 billion between 2000 and 2050. This study estimates year 2000 global yield reductions of three key staple crops (soybean, maize, and wheat) due to surface ozone exposure using hourly O₃ concentrations simulated by the Model for Ozone and Related Chemical Tracers version 2.4 (MOZART-2). We calculate crop losses according to two metrics of ozone exposure – seasonal daytime (08:00–19:59) mean O₃ (M12) and accumulated O₃ above a threshold of 40 ppbv (AOT40) – and predict crop yield losses using crop-specific O₃ concentration:response functions established by field studies. Our results indicate that year 2000 O₃-induced global yield reductions ranged, depending on the metric used, from 8.5–14% for soybean, 3.9–15% for wheat, and 2.2–5.5% for maize. Global crop production losses totaled 79–121 million metric tons, worth $11–18 billion annually (USD₂₀₀₀). Our calculated yield reductions agree well with previous estimates, providing further evidence that yields of major crops across the globe are already being substantially reduced by exposure to surface ozone – a risk that will grow unless O₃-precursor emissions are curbed in the future or crop cultivars are developed and utilized that are resistant to O₃.

http://www.sciencedirect.com/science/article/pii/S1352231010010137