1.5C is the (likely to be overshooted) goal. The IPCC report assesses that 2011-2020 is already 1.1C warmer than 1850-1900 (page 7), that the world has been warming by ~0.2C/decade (saw it somewhere), and that current policies (if implemented) will lead to a warming of +3.2C by 2100 (page 23). Page 16 shows various ways in which a +3.2C world will be hostile to humans. For instance most of south and south-east asia, and some of the most populated areas in Western Africa will experience temperatures and humidity levels that are dangerous for human survival >200 days a year. This is now all determined with rather high confidence.
False, 35C is described as the highest optimal temperature not the maximum in your link. Yields do slowly decline with increased temperature. For specifics, “Germination occurs within the temperature range of 50° to 107°F with an optimum temperature of about 87°F.”
Before saying "False" and dropping the mic, you should pull the paper and look at Table 1. High temperature stresses start at 25°C. Above 35°C, photosynthesis drops by 15%, grain size suffers, etc.
"Yields slowly decline" is a mischaracterization of the situation.
Ahh fantastic. Now let's talk about the rest of the flora and fauna that is absolutely essential for crop growth beyond the few staples that get researched.
https://www.ipcc.ch/report/ar6/syr/
1.5C is the (likely to be overshooted) goal. The IPCC report assesses that 2011-2020 is already 1.1C warmer than 1850-1900 (page 7), that the world has been warming by ~0.2C/decade (saw it somewhere), and that current policies (if implemented) will lead to a warming of +3.2C by 2100 (page 23). Page 16 shows various ways in which a +3.2C world will be hostile to humans. For instance most of south and south-east asia, and some of the most populated areas in Western Africa will experience temperatures and humidity levels that are dangerous for human survival >200 days a year. This is now all determined with rather high confidence.