Yes, fertility is below replacement in 183 out of 191 countries. True. But it depends. IPAT: impact = population times affluence times technology. Take away t

Yes, fertility is below replacement in 183 out of 191 countries. True. But it depends. IPAT: impact = population times affluence times technology. Take away the 700 million people with the highest incomes (10%), then about 90% of the impact is gone. I doubt that population decline will be that swift or deep, though. Technology won't save us either. If it isn't deployed commercially at billion-dollar scale now, it won't scale up enough in four decades to make much of a difference.