It’s also a bit wild to cite one data point of an unexpected state change and use it to assume with such confidence that another one will occur.
> The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.
Smart people make predictions about the future all the time. The problem is the future is hard to predict. The mere fact that birth rates in developed nations are falling below sustainment level calls into question any sort of extrapolation of when or if overpopulation will happen. That's not to say the Earth can support an infinite number of people because it can't; but that doesn't imply any specific trends we see right now will continue into the future.