Real world experiment (IMAGE) Columbia Climate School Caption Researchers have introduced artificially heightened levels of carbon dioxide to farm fields, and measured the results on crop production. Here, experimental plots at the University of Arizona's Maricopa Agricultural Center. Credit Courtesy Bruce Kimball/USDA Usage Restrictions Credit must be given. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.