It's a book by the GapMinder folks reminding us that India, China, world-health do-gooders and other folks have changed human society plenty in past few decades. On the one hand, this is happy "news"— things are improving. On the other hand, plenty of influential decision-makers have out-of-date worldviews and do some bone-headed things. But mostly it's a hopeful book. Though poverty's still in the news, it turns out that a huge long-duration effort has, slowly, eventually improved things quite a lot. So when you forward at a huge long-duration effort to, say, rein in climate change enough to avoid wiping out the human race, maybe there's hope that we'll get our act together enough to save many people eventually.