About the cover
Earth is getting a second chance. At the 1992 Rio Earth Summit, the worlds leaders pledged to protect the planets climate and biodiversity. Since then, however, the situation has deteriorated further. Twenty years on, on the eve of the second Rio Earth Summit, we report on what went wrong and how things may yet be put right. Elsewhere in the issue, a series of Reviews and research papers explores how biodiversity loss is affecting ecosystems, and how much the consumption patterns of the developed world are to blame. Cover by Julene Harrison (photo: Samuel Acosta/Shutterstock).