Cotton Response to Rising Air Temperature and CO2 Content
Yoon, S.T., Hoogenboom, G., Flitcroft, I. and Bannayan, M. 2009. Growth and development of cotton (Gossypium hirsutum L.) in response to CO2 enrichment under two different temperature regimes. Environmental and Experimental Botany 67: 178-187.
In terms of final yield, Yoon et al. report that at the lower of the two air temperature regimes, "final boll weight at harvest was 1.59 times (at 600 ppm) and 6.3 times (at 800 ppm) higher compared to ambient CO2," and they say that "increasing the temperature increased this difference, as the final boll weight was 34.1 times (at 600 ppm) and 23.3 times (at 800 ppm) higher compared to ambient CO2." In addition, they state that "the response of final lint yield to CO2 was more or less similar to the response of boll weight."
Both higher air temperatures and higher atmospheric CO2 concentrations -- individually and in combination -- were a great boon to cotton productivity in this well-controlled study, demonstrating that in this experiment not only were the "twin evils" of the radical environmentalist movement not detrimental to cotton growth and development, they were almost unbelievably beneficial.