" And yet we have already grown well beyond the earth’s limits. The last time planet Earth was able to support the human enterprise sustainably—that is, provide for human needs without degrading the principle of the earth’s ecological bank account—was 1975, when the earth’s population was 4 billion (Juniper 2013). As I write in 2018, global population is approaching 7.5 billion, and we have seriously degraded the earth’s carrying capacity—not only for humans, but for other species as well. "

― Douglas W. Tallamy , Nature's Best Hope: A New Approach to Conservation That Starts in Your Yard