Think he/she is referring to climate change. COVID is a good way to gain a mental understanding of what to expect when climate change finally hits as it will be much worse. I do think the odds of "billions" of dead is one of the less likely outcomes but maybe millions yes.
How do you exactly compare extremely slow, glacial environmental changes on geological timescales to a pathogen that engulfed the entire world in weeks?
What can anyone gain from such a comparison except baseless soundbites intended for fear mongering?
