1/7. The "nutrition scare" is marketing FUD. Increasing CO2 does not decrease crops' nutritional value, except under contrived circumstances. https://x.com/ncdave4life/status/1800278501674652017… I had an impromptu online debate about the nutrition scare with its most prominent promoter, mathematician Irakli_Loladze, in comments on that Quora answer. If you're not a Quora member you can't read it there, so I saved it here: https://sealevel.info/Is_Irakli_Loladze_right_that_rising_CO2_levels_are_affecting_the_nutritional_value_of_plants.html… If you skim it, do not overlook the important fact that since elevated CO2 is especially beneficial for legumes (beans, peas, etc.), which are grown for their high protein content, the rising CO2 level helps mitigate protein shortages in poor countries.

In that conversation Dr. Loladze admitted to me that food grown in greenhouses at 1500 ppmv is as nutritious as food grown outdoors with less than 1/3 that much CO2. https://www.youtube.com/watch?v=P2qVNK6zFgE… It is possible to contrive circumstances in which higher crop yields along with inadequate nitrogen fertilization cause crops to have lower percentages of wheat gluten and other proteins, and more carbohydrates. That's because proteins contain nitrogen, and carbohydrates don't. So if plants don't have enough nitrogen to support their growth rate, they tend to produce less protein. But that's only half the story. You see, among the crops which benefit MOST from elevated CO2 are legumes, like beans, peas, peanuts, clover and alfalfa—and they make their own nitrogen fertilizer! Legumes use symbiotic bacteria to "fix" nitrogen from the air, thus enriching the soil and obviating the need for nitrogen fertilization. Here's a paper about how elevated CO2 benefits legumes: https://www.frontiersin.org/articles/10.3389/fpls.2017.01546/full… Li, Y et al (2017). Elevated CO2 Increases Nitrogen Fixation at the Reproductive Phase Contributing to Various Yield Responses of Soybean Cultivars. Front. Plant Sci., 8:1546. doi:10.3389/fpls.2017.01546 Here's another paper: https://www.frontiersin.org/articles/10.3389/fsufs.2021.767998/full… Legumes are the crops most grown for their protein content. So, since elevated CO2 is especially beneficial for legumes, it helps mitigate protein shortages in poor countries. https://www.sciencedirect.com/science/article/abs/pii/S0308814605003687… Here's a timelapse video showing two legume seedlings growing with different CO2 levels: https://www.youtube.com/watch?v=P2qVNK6zFgE… Here's another article about legumes: https://www.fs.usda.gov/wildflowers/ethnobotany/food/legumes.shtml… So the very crops which elevated CO2 benefits most are the crops which make their own fertilizer, and which produce the most protein. Thus, elevated CO2 greatly improves food security and protein availability in third world countries. https://sealevel.info/learnmore.html?0=madrasfamine#famine… The scientific evidence is compelling that manmade warming is modest and benign, and CO2 emissions are highly beneficial. The benefits of more CO2 are large and well-measured, and the supposed major harms are hypothetical and implausible. Here are some relevant additional papers: https://sealevel.info/negative_social_cost_of_carbon.html…

2/4≫ For instance, here's a paper about what rising CO2 levels do for wheat: https://www.ncbi.nlm.nih.gov/pubmed/26929390 Fitzgerald GJ, et al. (2016) Elevated atmospheric CO2 can dramatically increase wheat yields in semi-arid environments and buffer against heat waves. Glob Chang Biol. 22(6):2269-84. doi:10.1111/gcb.13263.

https://apnews.com/article/fact-check-climate-co2-carbon-emissions-plants-crops-167887410508… it also decreases their nutritional value and has other negative impacts on the planet, such as increasing droughts and fires through climate change. Overall, the negatives far outweigh any benefits