Reference
Koti, S., Reddy, K.R., Kakani, V.G., Zhao, D. and Gao, W. 2007. Effects of carbon dioxide, temperature and ultraviolet-B radiation and their interactions on soybean (Glycine max L.) growth and development. Environmental and Experimental Botany 60: 1-10.
What was done
Soil-Plant-Atmosphere-Research (SPAR) chambers at Mississippi State University (USA) were used to investigate the effects of doubled atmospheric CO2 concentration (720 vs. 360 ppm) on the growth and development of six well watered and fertilized soybean (Glycine max L.) genotypes grown from seed in pots filled with fine sand and exposed to the dual stresses of high day/night temperatures (38/30°C vs. 30/22°C) and high UV-B radiation levels (10 vs. 0 kJ/m2/day).
What was learned
Koti et al. report that "elevated CO2 partially compensated [for] the damaging effects on vegetative growth and physiology caused by negative stressors such as high temperatures and enhanced UV-B radiation levels in soybean," specifically noting, in this regard, CO2's positive influence on the physiological parameters of plant height, leaf area, total biomass, net photosynthesis, total chlorophyll content, phenolic content and wax content, as well as relative plant injury.
What it means
With respect to almost all of the ways in which high air temperatures and high UV-B radiation levels negatively impact the growth and development of soybeans, elevated atmospheric CO2 concentrations appear to be able to proffer significant ameliorative relief.