Bill Gates has clearly not studied climate science, he just assumes the IPCC reports and models are correct. Then he accepts their health and economic projections, built with climate model output. He apparently did no due diligence or independent research.
So after blindly accepting, the consensus position on climate science he then proceeds to tell us what we must do to combat his hypothesized scourge of climate change. Later he implores the governments of the world to unite in forcing the public to do what he wants.
This is a very shallow look at a very complex topic. I do not recommend buying or reading the book.