There are no models from standard institutions that I'm aware of in which projected climate change destroys all multi-cellular life, that's exactly the kind of absurdly over the top claim the article is arguing against. Go look at long term temperature graphs over time and then look at current temperature trends as measured by satellites:

https://www.drroyspencer.com/latest-global-temperatures/

They show a slight warming trend, but still quite under the projections and nowhere near enough to cause more than economic disruption, let alone destroy humans, let alone all multi-cellular life. The climate has had far greater extremes in the past and multi-cellular life was just fine.