What is meant by that is that thebcurrent worldnpopulation exceeds Earth's carrying capacity by a factor of 0.2. That means that there are more people than the Earth can sustainably -- note the world sustainably. Once you overshoot the carrying capacity, you're in a situation where even the Earth's renewable resources are being depleted, in a way that may not recover for a very long time.

Overpopulation is a glibal crisis.