This type of experiment applies a heating treatment to open-field plant canopies, simulating models of future warmer conditions. Dr. Bruce Kimball of the Arid-Land Agricultural Research Center and colleagues design and operate such experiments. In 2005 they developed a proportional–integrative–derivative control system for controlling the rise in temperatures. Apogee [Infrared Radiometers] provided the data on control and heated plot temperatures. Similar infrared warming experimentation using this design and Apogee sensors are also underway in Haibei, Qinghai, China and Cheyenne, WY .

Kimball, B. A., 2005.
Theory and performance of an infrared heater for ecosystem warming.
     Global Change Biology,
     11(11):2041-2056.