Environmental history is the study of how humans have shaped environments in the past, as well as how environments and environmental changes have shaped us, and how people have regulated their management of natural resources. Today, a new chapter in environmental history is being written: a newly globalized society is confronting a global …

There is little doubt that most people tire of hearing about problems only and would like to hear about solutions. But disconnecting the solution from the problem has its own dangers. Many of the most serious problems facing society today—those in most urgent need of solutions—are so-called wicked problems. These are complex, not amenable to …

Author Note: This article is based on the papers “A safe operating space for humanity,”1 published in Nature, and “Planetary boundaries: Exploring the safe operating space for humanity,”2 published in Ecology and Society. See these papers for a complete description of the planetary boundaries. Here, we present the underlying concepts and …