A study suggests that the US agricultural economy is becoming increasingly sensitive to climate. Because local climates dictate crop yields and agricultural economic returns, previous studies have had limited success capturing the overall consequences of climate change on the US agricultural economy. Xin-Zhong Liang and colleagues compared climate variables during the period 1948-2011 in specific US regions with a measure of agricultural efficiency called total factor productivity (TFP), which is the ratio of agricultural outputs per production input. TFP fluctuations were larger and more tightly correlated with climate variations from 1981-2010, compared with the period 1951-1980. A regression model suggested that seasonal and regional temperature and precipitation fluctuations explain almost 50% of TFP growth variation during 1951-1980 and approximately 70% of TFP growth variation during 1981-2010. The findings suggest that US agricultural productivity has become more sensitive to climate since 1980. Based on current climate projections, the regression model predicted that TFP could decrease by an average of 2.84-4.34% per year under medium to high emissions scenarios; in either case, TFP would fall to pre-1980 levels by 2050, despite accounting for present rates of innovation. According to the authors, policies that promote adaptation and technological advances could help the United States maintain current agricultural productivity levels. - Read at PNAS
Article #16-15922: “Determining climate effects on US total agricultural productivity,” by Xin-Zhong Liang et al.