The most significant part of the U.N. pact is a commitment to protect 30% of land and water considered important for biodiversity by 2030, up from 17% of terrestrial and 10% of marine areas.

"The loss of nature and rising water insecurity are global health threats that must be confronted together," Secretary of State Antony Blinken said.

The influential and sometimes controversial Harvard professor first made his name studying ants. He later broadened his scope to the intersection between human behavior and genetics.