But, as with most things, in the right dosage it's great stuff, still too much or too little and things start going wrong.
We've already seen studies indicating that invasive vines and weeds are some of the big winners in a world with increasing atmospheric CO2. Now here's some evidence that heightened CO2 may actually be counter-productive for some of the grain plants we depend on the most.
As CO2 Levels Rise, Some Crop Nutrients Will Fall
This story was posted by Diana Yates, Life Sciences Editor for news.illinois.edu, 5/7/2014
CHAMPAIGN, Ill. — Researchers have some bad news for future farmers and eaters: As carbon dioxide levels rise this century, some grains and legumes will become significantly less nutritious than they are today.
The new findings are reported in the journal Nature. Eight institutions, from Australia, Israel, Japan and the United States, contributed to the analysis.
The researchers looked at multiple varieties of wheat, rice, field peas, soybeans, maize and sorghum grown in fields with atmospheric carbon dioxide levels like those expected in the middle of this century. (Atmospheric CO2 concentrations are currently approaching 400 parts per million, and are expected to rise to 550 ppm by 2050.) …
The teams simulated high CO2 levels in open-air fields using a system called Free Air Concentration Enrichment (FACE), which pumps out, monitors and adjusts ground-level atmospheric CO2 to simulate future conditions. In this study, all other growing conditions (sunlight, soil, water, temperature) were the same for plants grown at high CO2 and those used as controls.
The experiments revealed that the nutritional quality of a number of the world’s most important crop plants dropped in response to elevated CO2.
The study contributed “more than tenfold more data regarding both the zinc and iron content of the edible portions of crops grown under FACE conditions” than available from previous studies, the team wrote.
“When we take all of the FACE experiments we’ve got around the world, we see that an awful lot of our key crops have lower concentrations of zinc and iron in them (at high CO2),“ said University of Illinois plant biology and Institute for Genomic Biology professor Andrew Leakey, an author on the study. “And zinc and iron deficiency is a big global health problem already for at least 2 billion people. …
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