2019 Australia's Hottest and Driest - WMO, page-58

You are ignoring physiological evolution and the extended time span, which allowed for adaptation. The current atmospheric changes are dramatic, which have and will cause disruption on a grand scale. We are no longer just a few simians swinging from trees. Even if we do nothing to ameliorate the risk, humans will survive regardless of adaptation (maybe), because we are smart (some of us). But at what cost? - famine, war, floods, untold deaths, species destruction, environmental apocalypse?

To do nothing is a fools errand.