I used to think the top global environmental problems were biodiversity loss, ecosystem collapse and climate change. I thought within 30 years of good science we could address those problems, but I was wrong.

The top global environmental problems are selfishness, greed and apathy—and to deal with these we need a spiritual and cultural transformation, and we scientists don’t know how to do that.

Gus Speth, environmental lawyer and co-founder of the Natural Resources Defense Council