I was intrigued by the title and looked up the book and found this review, and it seems to bring up some good points.
https://www.goodreads.com/review/show/102880724?book_show_ac...
I very much agree with that philosophy and would consider myself a rational optimist if I had to label, hence the intrigue.
While optimism is good, I think it needs to be paired with equally important perspective. As that review points out, the general trend doesn't mean we can't go backward for long periods of time in multiple areas. That optimism needs to be paired with a push for improvement over complacency, which I think is the easy comfort optimism can give.
Sorry if this is preaching to the choir, but hopefully someone gains value out of this.
Edited because I just trailed off in the middle of a thought on my first go round.
1. Climate change: Ridley calls himself a "luke-warmer". He doesn't deny that a doubling of carbon dioxide causes a 1 degree celsius increase in temperature, but he accumulates various evidence in the book suggesting that estimated feedback effects (water vapor, etc.) are in excess of what's likely. This claim certainly falls into one of the debatable aspects of the book and I'm not an expert to really evaluate it. I think it's a valid criticism that Ridley is excessively optimistic on existential risks. My guess is that he has a Bayesian prior that dooms-dayers are more likely to be wrong than not. He has many examples in the book of experts predicting existential risks in history and being wrong, and I think this colors his view of all experts. I think those historical examples of wrong doomsdayers is an interesting and important perspective.
2. Societal Collapse: I believe Ridley wrote about how the black plague may have been an important catalyst in igniting the renaissaince, so I don't remember him making teleological arguments. I don't think Ridley ever claimed that there won't be problems or collapse, but simply that if you look at the aggregate statistics, humans have been improving dramatically in the last few thousand years, largely driven by new forms of energy in the last few hundred years.
3. Materialism: I don't understand this critique. I already see evidence of movements forming to help people find more meaningful lives: the scientific field of Positive Psychology and Meaning-in-life research by professors such as Dr. Steger, The School of Life, etc.