What was done
The authors studied how temperature, precipitation and solar radiation influenced the yields of soybeans and peanuts over a 30-year period in the southeastern United States and used the results to predict future crop yields based on climate output from various global circulation models (GCMs) of the atmosphere.

What was learned
At ambient CO2 concentrations, GCM scenarios pointed to a decrease in soybean and peanut yields by the year 2020, due in part to predicted changes in temperature and precipitation.  However, when the yield-enhancing effects of a doubling of the atmospheric CO2 concentration were included in the simulations, a completely different projection was obtained - a yield increase for both crops.

What it means
Although we have little faith in GCM scenarios, it is interesting to note that their climate change predictions often result in positive outcomes for agricultural productivity when the direct effects of elevated CO2 on plant growth and development are included in the analyses.  These results support the findings of the voluminous Journal Reviews on our website, which describe the stress-ameliorating effects of atmospheric CO2 enrichment on plant growth and development under unfavorable growing conditions characterized by high air temperatures and inadequate soil moisture.