In the ISCID Brainstorms forum Emeritus Professor of Biology John A. Davison challenged my assertion that atmospheric CO2 increases are a good thing for plant growth. He said while it might apply to trees it doesn’t apply to grasses such as rice which don’t yield more grain in an elevated CO2 environment. He then went on to say that only in the laboratory can benefits be observed from elevated CO2 where other potentially limiting factors (sunlight, nutrients, water) aren’t an issue. Sorry John, but that’s just wrong on all counts.
Rice grain yields increased 60% in outdoor field tests with elevated CO2. Yield peaked at 28C and then declined 10% for each additional degree. Even the global warming hysterics readily admit that average temperatures will only increase a few degrees at most. The cool thing about temperature though is you can compensate for an undesirable increase by shifting either your growing season and/or your latitude. In any case the actual grain yield increase obtained from elevated CO2 are still double any losses engendered by projected temperature increases.
Source: Journal of Experimental Botany
Temperature Effects on Rice at Elevated CO2 Concentration
In addition to increased grain yield elevated CO2 also reduces the impact of drought. Rice grown in the field at elevated CO2 levels consumed 10% less water.
Source: USDA Agricultural Research Service
Impacts of Drought, High Temperature and Carbon Dioxide on Rice Physiological Processes
It is hard to believe, isn’t it? 🙄