During the past 30 years, a network consisting of 14 long-term research facilities from five continents has simulated future levels of carbon dioxide (CO2) to forecast its impact on crops. The 'Free-Air Concentration Enrichment' (FACE) experiments are conducted outside in real-world field conditions to capture the complex environmental factors that impact crop growth and yield.
A review published in Global Change Biology synthesizes 30 years of FACE data to grasp how global crop production may be impacted by rising CO2 levels and other factors, a less optimistic one than the authors' previous review published 15 years ago in New Phytologist. The reviews consider two groups of plants: most crops are C3 (including
soybeans, cassava, and
rice), which are less efficient at turning CO2 and light into energy during photosynthesis. C4 plants, such as
corn and sugarcane, supercharge photosynthesis by using some of the light energy they receive to concentrate CO2 within their leaves, making them up to 60 percent more efficient.