I still feel like his New York magazine piece that was condemned by many as too scary marks a turning point in the public discourse around climate change.
Keep in mind that because of how book publishing works that book is now already several years out of date. It doesn't reflect the draft papers for AR6 (which to be fair are still just drafts) and it doesn't reflect the fact that arctic melting is already tracking the RCP8.5 scenario of AR5 for decades from now. It also includes the authors personal optimism for direct air capture miracle technology, which now a few years later has still yet to appear (speaking of, how's Prometheus doing YC?)