Your point 4 is exceedingly optimistic. The environment won't "recover". It will certainly reach a stable equilibrium, but that equilibrium may well be something we, as a species, won't particularly like or thrive in.
While we're talking arable land, we need to consider that the majority of the land that could be deployed as farmland is home to a whole host of ecosystem services and bio-resources that, if destroyed, won't be coming back. Temperatures can stabilize, pollution can go down, but if we can't stave off habitat loss and destruction, we'll be a lot worse off than today. More people means they all need somewhere to live, somewhere to grow their food, and somewhere to put their waste. That space is all at the expense of organisms we need. We can't just shrug our shoulders and assume everything will bounce back eventually.
As for the fertility implosion itself - it needs to happen, sooner or later. Those 20-year olds in the Middle East and the babies being born today? Yeah, they'll get old, too. Brooks' view on demographics is a pyramid scheme, we need to figure it out, and I'd sooner have it happen now while we still have a relative diversity of species and environments left.
While we're talking arable land, we need to consider that the majority of the land that could be deployed as farmland is home to a whole host of ecosystem services and bio-resources that, if destroyed, won't be coming back. Temperatures can stabilize, pollution can go down, but if we can't stave off habitat loss and destruction, we'll be a lot worse off than today. More people means they all need somewhere to live, somewhere to grow their food, and somewhere to put their waste. That space is all at the expense of organisms we need. We can't just shrug our shoulders and assume everything will bounce back eventually.
As for the fertility implosion itself - it needs to happen, sooner or later. Those 20-year olds in the Middle East and the babies being born today? Yeah, they'll get old, too. Brooks' view on demographics is a pyramid scheme, we need to figure it out, and I'd sooner have it happen now while we still have a relative diversity of species and environments left.