Wheat Production in a CO2-Enriched World of the Future
Wilcox, J. and Makowski, D. 2014. A meta-analysis of the predicted effects of climate change on wheat yields using simulation studies. Field Crops Research 156: 180-190.
To answer their question, Wilcox and Makowski "performed a literature search to compile peer-reviewed journal articles describing the response of wheat to climate change simulated using computer models." And in doing so, they say that "90 articles were found with yield data suitable for the meta-analysis." From those articles the two French researchers ultimately determined that "more than 50% of the simulated relative yield change resulted in yield losses when mean temperature change is higher than 2.3°C, or mean precipitation change is null or less, or when CO2 concentration is lower than 395 ppm." However, their results showed that, on average, "the effects of high CO2 concentrations (>640 ppm) outweighed the effects of increasing temperature (up to +2°C) and moderate declines in precipitation (up to -20%), leading to increasing yields."
In concluding their study, Wilcox and Makowski say their results "provide an overall positive outlook for the future of wheat production."