1/9. You're right, Jim. BBanana wrote, "Temperature increases have already reduced global yields of major crops." That's false. It's long been known that warming generally improves agricultural productivity. Here's a CIA study which summarized the relation: http://climatemonitor.it/wp-content/uploads/2009/12/1974.pdf…

2/10. Fig.7 from that study shows the number of people who could be supported per hectare of arable land, vs. temperature. The 7 curves represent varying precipitation rates. In each case, higher temperatures allow the support of higher populations, due to better crop yields. https://sealevel.info/CIA1974ClimateReport/CIA1974_excerpt10a.png…

3/10. Also, elevated CO2 directly improves crop yields, and mitigates drought impacts. That's helping make famines rare for first time in history. https://twitter.com/ncdave4life/status/1207159482607898625… Those too young to grok how revolutionary that is should count themselves blessed! Famine used to be a scourge comparable to war & disease.

4/10. Climate change is real, but there's no scientific evidence it's harmful. Scientists call warm climate periods "climate optimums." The benefits of CO2 emissions are so enormous that Scientific American once called CO2 "precious air fertilizer." https://ourworldindata.org/famines https://ourworldindata.org/famines

5/10. In support of BBanana's erroneous claim he cited Zhao et al 2017. But Zhao et al admitted that their study was about what WOULD happen to crop yields "without CO2 fertilization, effective adaptation, and genetic improvement." https://sealevel.info/learnmore.html?0=agriculture#benefits… https://sealevel.info/learnmore.html?0=agriculture#benefits…

6/10. Of course "without CO2 fertilization" means they ignored the beneficial effects of higher CO2 levels. That obviously divorces the paper from any pretense of representing reality. https://sealevel.info/learnmore.html?0=preciousairfertilizer#agriculture… https://sealevel.info/learnmore.html?0=preciousairfertilizer#agriculture…

7/10. And it gets worse. Do you know what "effective adaptation" to a warming climate means? For annual crops, it just means adjusting spring planting dates and/or cultivar selection.

8/10. It's not rocket science. In America's breadbasket, moving up planting date by about six days fully compensates for 1°C of warming, as you can see:

9/10. To assume that farmers won't do that, as these 29(!) authors did, is to assume farmers are idiots, who can't figure out when they should plant their crops. That seems like "projection," to me.

10/10. The reality is that most farmers are not idiots, and the higher CO2 levels go the more productive our farms will be. That's not speculation, that's the measured conclusion of thousands of rigorous agronomy studies. https://sealevel.info/negative_social_cost_of_carbon.html… https://sealevel.info/negative_social_cost_of_carbon.html…