New warning

In late 1992, 1700 scientists from around the world issued a dire “warning to humanity.” They said humans had pushed Earth’s ecosystems to their breaking point and were well on the way to ruining the planet. To mark the letter’s 25th anniversary, researchers have issued a bracing follow-up. In a communique published in the journal BioScience, more than 15,000 scientists from 184 countries assess the world’s latest responses to various environmental threats. Once again, they find us sorely wanting.