The World Meteorological Organization estimates that in the 50 years from 1970 to 2019, deaths from climate dropped to one-third[0]. That's not one-third the rate; that's one-third of the absolute number of deaths, even as the world population more than doubled in that time period and atmospheric CO2 went from ~325ppm to ~410ppm.

In my opinion, this reduction in deaths is mostly due to the increasing ability of the developing world to better master their environment, enabled by technological advances powered largely by cheap energy from fossil fuels. If you have alternative explanations, I'm happy to hear it. But as the evidence stands, it would be more delusional to think climate change will cause rampant mass deaths.

[0]: https://library.wmo.int/viewer/57564/download?file=1267_Atla...