I agree with the skepticism about his panic. There has always been the optimists and the pessimists, nothing new there. Projections >30 years into the future are mostly doomed anyways.
Moreover what often amuses me is how these analyses tend to ignore the predictable part of technological progress and how that negatively affects the relevancy of their projections.
We went from the first flight to the moon landing in 66 years. Autonomous cars are performing their first test-runs in real traffic today. Asimo & friends are demonstrating quite impressive tricks today.
Call me naive but personally I don't have the slightest doubt that a large portion of all jobs will be taken by robots in 60 years from now. This will not just change the job market or certain industries, it will fundamentally change how our societies work. He doesn't seem to consider that at all.
So, he's worried about the global population being half of what it is today in 2150?
2150?
140 years from now?
I guess his musings about 2150 are about as relevant as those that a person in 1870 could have made about today...