Rather we know SOYbeans about higher CO2 levels. Researchers at the University of Illinois and the Dept. of agriculture have tested real soybeans in real fields under the higher levels of CO2 predicted for 2050. Here's some of what they found:
The plants respired at a higher rate. The plants also produced more sugars and larger crops. Many of the genes in the plants were activated by the higher CO2 levels, enabling the plant to make use of the higher CO2 levels.