I'm really shocked to see this book essentially panned in reviews below. Having read and re-read this book multiple times since its publication, I find it to be as important and valuable now as ever.
Much of the criticism insists that what he suggests in order to reduce each of our footprints to a sustainable level moving forward is completely impossible for anyone in the real (American) world, especially the suggestion to only have one child.
Seriously? He's not suggesting that it's the usual, expected, or easiest thing. Sadly, it's still not very usual or expected, decades after folks first started talking (in the modern era) about living this way (not to mention all the times throughout recorded history that different folks have advocated for these kinds of individual changes for various reasons). But frankly, it's really not that hard. In fact, it's arguably a good deal easier -- and certainly far more affordable -- than living a more usual, expected life. It does take some courage, creativity, innovation, determination, hard work with real physical things (like soil, plants, shovels, metal, and wood; as opposed to digital currencies, social media profiles and posts, or online reviews like this), and humility, in my limited experience. The findings and engineering-minded calculations of someone like Merkel, who then and now has been in this struggle a lot longer, can help in figuring out the most effective changes to make.
And yes, you may not want to have two or more children. That isn't addressed to folks who already have multiple kids. No one's asking you to off 'em. But what's wrong with choosing to have fewer?
The most valid criticism I see is that this is a guidebook for reducing one's own personal/family footprint, not a guidebook for making change at a policy level on a larger scale. Of course that's true, but that's not what this book purports to be. There are other books out there to guide us along that critical part of the path, and I hope that reviewer reads those, too, and engages with the world around us in that way as they've expressed the desire to do.