1/7. Not really. There've been thousands of rigorous Open Top Container (OTC), Free Air Carbon Enrichment (FACE), and Greenhouse studies, measuring how crops respond to varied CO2 levels, in various conditions, including drought. Many are indexed here: http://co2science.org/data/plant_growth/plantgrowth.php…

2/7. You can also compare crop yield trends in places with plenty of synthetic N & mechanization to places like most of Africa, where there's little of that. Here's some yield data for cereal crops. Yields tripled since 1961 in Europe & N. America, and doubled in Africa. https://ourworldindata.org/crop-yields Even Africa has had some yield improvements due to synthetic N & mechanization, but most of the crop yield improvement there is almost certainly due to CO2. https://sealevel.info/ourworldindata_cereal_yield_4regions_1961_and_2022_annot1.png…

3/7. This study reported, "We consistently find a large CO₂ fertilization effect: a 1 ppm increase in CO₂ equates to a 0.4%, 0.6%, 1% yield increase for corn, soybeans, and wheat, respectively." Taylor, C & Schlenker, W (2021). Environmental Drivers of Agricultural Productivity Growth: CO2 Fertilization of US Field Crops. National Bureau of Economic Research, no. w29320. doi:10.3386/w29320. https://sealevel.info/Taylor_and_Schlenker_2021-2023_CO2_Fertilization_of_US_Field_Crops_v2_doi_10.3386-w29320.pdf…

4/7. Note that human CO2 emissions have raised CO2 levels by about 140-145 ppmv since the start of the industrial revolution (a 50% increase, from about 280 ppmv to just over 420 ppmv), with 105 ppmv of that increase having come since 1960: https://sealevel.info/co2.html

5/7. So, for soybeans, for example, +0.6% per 1 ppmv CO2 means 1.006^105 = 1.87, i.e., an 87% improvement in soybean yield, due to the increase in CO2 level. https://www.google.com/search?q=1.006%5E105…

6/7. Plus, CO2 Fertilization is not the only way that elevated CO2 boosts crop yields. https://x.com/ncdave4life/status/1808682423116234909…

7/7. The fact that elevated CO2 is very beneficial for crops has been settled science for more than a century. In 1920(!!!) Scientific American reported on German agricultural experiments, measuring the effects of elevated CO2 on a wide variety of crops. https://sealevel.info/ScientificAmerican_1920-11-27_CO2_fertilization.html#:~:text=precious%20air%20fertilizer… They confirmed Arrhenius: elevated CO2 is tremendously beneficial for all of the crops that they tested. In fact, it is so beneficial that they called CO2 "the precious air fertilizer."