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Does More Carbon Dioxide Mean Increased Crop Water Productivity? (arstechnica.com)
An anonymous reader points us to an Ars Technica report: For the most part, we think of rising levels of carbon dioxide as an environmental problem. But atmospheric CO2 can also boost agricultural productivity by helping plants grow. How do these potential issues balance out? In an investigation recently published in Nature Climate Change, scientists have looked into the global implications of carbon dioxide's ability to enhance agricultural productivity. Increased levels of CO2 can enhance photosynthesis and reduce leaf-level transpiration, the process by which some of the water that plants draw from the ground gets released back into the atmosphere. These changes can reduce growing seasons and water loss. The result could be an increase in what's called "crop water productivity," i.e. the amount of food produced for each unit of water expended. If elevated CO2 levels increase crop yield and reduce water consumption at large scales, this could help ensure water and food security despite the climate disruptions. By combining data from a massive network of field experiments and global crop models, the scientists claimed that depending on the crop type, global crop water productivity will increase by 10 to 27 percent by the 2080s. Arid regions exhibited large increases that were based on crop type.
Measurable nutrients from food has declined by up to 40% since the 1930s and by about 15% since 1950.
The water content of fruits has exploded (most fruits are basically packed nutrientless water and sugar).
Faster growing crops boosted by CO2 will have even less time to draw as many nutrients from the soil.
We really should measure a random sampling of end consumer food products for nutrients each year and then require current real values to be on the food labels. Monsanto, Conagra and others spend millions to prevent that kind of labeling however. And do everything they can to muddy what organic and natural means.
But you can't trust organic and natural either outside of constant testing. Farmers want to make money- they'll try something "organic" which is actually unsafe.
So send agents to stores to buy food and then measure it. Then post the results on the web and require each seller to use that nutritional data on labels for their food until the next test.
She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
I come from a greenhouse family, and I remember using CO2 generators in the 90's briefly. I asked about this a few months ago and they quit because it prompted too much growth in some crops so they nixed the idea.
The reason I asked the question is I was coming back from a small class put on by MSU Extensions (Eric Runkle lead it) about LED lighting. He briefly touched on CO2 generation and it was basically a toss out of... "Yeah, we used to suggest that but ambient is now over 400ppm, so if you think you're low just crack a vent. I've seen some greenhouses down to 200ppm. Impressive they had it that sealed up, but just vent and you'll come back into the 400's." -- paraphrasing a lot there. I didn't take notes.