Warmer temperatures provide little benefit in offsetting cold stress in Canadian crop yields

Abstract The net effect of warmer temperatures for cold-climate agriculture remains unknown: cold temperatures disrupt production, but warmer temperatures can also bring yield-reducing extreme heat. We introduce an approach to measure cold-temperature exposure using sinusoidal degree days, an exact analog to the approach widely used to measure heat exposure. Applying this approach to model the yields of six Canadian crops, we find yield penalties to cold-temperature exposure mirror those from extreme heat. While average yields under low- and high-emission scenarios increase significantly when warmer days mitigate cold damage, these gains are too small to offset additional extreme-heat damage, and the net effect remains broadly negative. For barley, canola, oats and wheat, damages are severely negative (−28.4% to −57.8% loss). For maize and soybean, outcomes range from no distinguishable change to moderate losses (−5.2%). Additionally, yield risk increases, with higher coefficients of variation and low-yield probabilities across all scenarios.