Let’s not be hyperbolic. Without even getting into the futility of predicting something as complex as future mortality rates, the worst case projections go into tens of millions additional deaths due to climate change over the century (if that sounds like a lot, global deaths per _year_ are on the order of 50 million, so this is a few percent increase).

https://impactlab.org/research/valuing-the-global-mortality-...

https://www.nature.com/articles/s41467-021-24487-w