Harsh but true. In the 13th Century when the Little Ice Age started the population of England crashed 50% in 100 years. Without chemical fertilizers, which require great amounts of energy to produce, the world is looking at a 75% depopulation scenario.

However, the RATE of depopulation is crucial. A managed decline of 1% population decline per year over 75 years, is vastly preferred over a 75% decline in say 5 years.