Here's the thing - there are two different photosynthetic pathways that food crops use, called C3 and C4 photosynthesis. There is a third - CAM photosynthesis - which doesn't play as big a role in agriculture. C3 photosynthesis is an older process, that developed at a time when atmospheric CO2 levels were decidedly higher than now. The C4 process arose later, mostly in corn, sorghum, and sugarcane. It's a more efficient process, as one might expect, since it developed at a time of lower CO2 levels. Both types employ the Calvin cycle to produce sugars, but the C4 process uses a more efficient four-carbon-atom intermediary - thus the name, C4.

However, a great deal of human food crops utilize the older C3 process. This means that an increase in atmospheric CO2 more closely approximates the condition in which C3 photosynthesis originated. This results in increased crop yield in C3 plants. As Vijay Jayaraj writes:

Higher ambient CO2 levels allow C3 plants to photosynthesize more efficiently while losing less water. The benefits of elevated CO2 aren’t merely theoretical, as proven in field studies that have confirmed laboratory findings.

These studies, conducted in real-world conditions, show consistent yield increases across various C3 crops. Wheat yields increase by 20-30% under elevated CO2 conditions, while rice shows increases of between 15-32%. Soybeans, another crucial C3 crop, exhibit yield increases of up to 46% in some studies.

Perhaps nowhere is the CO2 effect more evident than in greenhouse cultivation. Modern greenhouse operators routinely boost productivity by elevating CO2 levels to 800-1,000 parts per million (ppm), which are well above current atmospheric levels of around 420 ppm. The results are striking: tomato yields increase by 40-50%, cucumber production rises by 30-40%, and growth of lettuce and other vegetables accelerates significantly. //

A resolution worth adopting this New Year would be to reject the coordinated demonization of CO2 by climate scaremongers and to celebrate it for what it is: the gas of life.