To help transform our understanding of the biosphere, ecologists — like climate scientists — should simulate whole ecosystems, argue Drew Purves and colleagues.

Protected areas (PAs) are a cornerstone of conservation efforts and now cover nearly 13% of the world’s land surface, with the world’s governments committed to expand this to 17%. However, as biodiversity continues to decline, the effectiveness of PAs in reducing the extinction risk of species remains largely untested.

Many biofuels are associated with lower greenhouse gas emissions but have greater aggregate environmental costs than gasoline.