Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2002
Publication Date: 9/15/2002
Citation: Idso, S.B., Kimball, B.A., Shaw, P.E., Widmer, W., Vanderslice, J.T., Higgs, D.J., Montanari, A., Clark, W.D. 2002. The effect of elevated atmospheric co2 on the vitamin c concentration of (sour) orange juice. Agriculture Ecosystems and the Environment 90(1):1-7.
Interpretive Summary: The World Health Organization recently reported that more than half the people on the planet are malnourished; and in light of this problem, the agricultural research organizations of all countries have a moral responsibility to strive to boost crop productivity and improve the nutrient content of edible plants. In meeting this obligation, we evaluated the effects of a 75% increase in the air's carbon dioxide (CO2) concentration on these two aspects of fruit production in a long- term study of sour orange trees. In years of normal productivity, we observed the 75% increase in atmospheric CO2 to produce a 75% increase in the number of oranges harvested; and we found the vitamin C concentration of juice derived from the CO2-enriched oranges to be 5% greater than the vitamin C concentration of juice derived from oranges produced in normal air. In addition, when elevated CO2 boosted fruit production by 200% or more, the CO2-induced increase in orange juice vitamin C concentration was even greater, rising as high as 15%. We conclude that these benefits of the ongoing rise in the air's CO2 concentration should be a great boon to humanity in the years ahead, helping to meet the world's need for not only more food, but more nutritious food.
Technical Abstract: Over five of the last six years of an eight-year experiment, a 75% increase in atmospheric CO2 concentration increased the number of sour orange tree fruit by 74% +/- 9% and the vitamin C concentration of their juice by 5% +/- 1%, while in years of greater CO2-induced fruit production, the vitamin C increase was as high as 15%.