There is every sign that humanity has entrained a sixth great
extinction episode in the history of life on Earth. Species are
disappearing at dozens of times the “background” rate—the
average rate that has prevailed during geological periods
outside of previous mass extinctions. The diversity of
populations, essential for the delivery of crucial ecosystem
services, is being lost even faster. These losses are mostly
irreversible, and in aggregate they threaten to unravel the very
fabric of civilization. Yet most people are unaware of the
peril. They don’t realize that populations of animals, plants
and microbes are essential to the functioning and overall
stability of our life-support systems. Among ecosystem services
they provide, interacting organisms stabilize climate and reduce
human vulnerability to extreme weather events (floods, droughts,
destructive storms) and even tsunamis. They help prevent soil
erosion and recycle essential nutrients, thus preserving the
productivity of farmland and forests. They h