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A Six-Decade Analysis of Growing Season Temperature Change in Illinois

Paper Reviewed
Dahal, V., Gautam, S. and Bhattarai, R. 2018. Analysis of long-term temperature trend in Illinois and its implication on the cropping system. Environmental Processes 5: 451-464, doi: 10.1007/s40710-018-0306-7.

Writing as background for their study, Dahal et al. (2018) say that Illinois ranks "either first or second in soybean production and second in corn production among the Midwestern [US] states, with more than 75% of its land used for crop production." However, because of its climate, only a small window of time is suitable each year for food production, particularly corn. Outside this period, temperatures typically present "detrimental effects [for] crop growth."

Given model projections of a changing climate that may negatively impact future crop yields, Dahal et al. set out to investigate past changes in temperature across Illinois, which analysis provides a good evaluation of the verity of future projections given the increase in atmospheric greenhouse gas concentrations over the past several decades. In doing so, twelve temperature-related parameters were examined on annual, seasonal, and crop growing-season-relevant scales for 115 stations over the period 1951-2010.

According to the three Department of Agricultural and Biological Engineering researchers from the University of Illinois at Urbana-Champaign, the results of their study revealed that "most of the stations of the state do not show significant change in the temperature parameters," adding that "among those stations where the change is significant, the majority show a cooling trend." What is more, they further note that "it was especially significant agriculturally that the summer days show a cooling effect," which implies "a decreasing exposure of the crops to heat stresses."

In light of these and other changes in temperature favorable to crop growth, Dahal et al. write that "we can safely conclude that over the second half of the twentieth century, the temperature has shown characteristics that are very encouraging for the farmers of Illinois." Consequently, the scientists correctly write that "climate change has not yet manifested itself in the state" and that "any changes in temperature observed in the last 60 years have only helped towards catalyzing the agricultural productivity."

It would thus appear that climate alarmists have got things backwards. Not only has the extra CO2 that has been added to the atmosphere over the past six decades directly stimulated crop production and yield, it has also likely induced an era of more favorable growing season temperatures. And that is a win-win situation for ensuring the future food security of the planet!

Posted 5 November 2018