Is increased corn yield really the silver lining of climate change?

Although it is possible that warming while temperature maxima decreased (1) contributed to increasing yields, a much more careful analysis is warranted before making potentially harmful statements such as “better weather experienced by US maize accounts for 28% of yield trends since 1981,” as Butler et al. (2) state in PNAS. To effectively measure contributions of climate changes to yield, two alternatives are possible (but unequal in strength of results): ( i ) a dataset containing the same varieties grown from 1981 to 2017 with minimal changes to management practices (empirical approach) or ( ii ) including periods when shifts in temperature trends were not following those in the period studied, along with many more variables to explicitly account for changes in cultural practices and … [↵][1]2To whom correspondence should be addressed. Email: ap874{at}cornell.edu. [1]: #xref-corresp-1-1