Although the environmental issues discussed in this section are presented separately, they all interact within the complex backdrop of global change. Our ability to understand and unravel the integrated nature of environmental challenges is improving, enabling us to consider various solutions to the different problems of a complicated world and choose the best course to follow – one that causes the least damage, and leads to the most benefits.

It is also important to tease apart interacting local, regional, and global drivers of environmental change and to recognize that they vary substantially from place to place. This is vital to developing the appropriate mix of responses for any situation. Stratospheric ozone depletion, climate change, and biodiversity, for example, require global solutions. In other cases, including fisheries and various challenges related to nitrogen, regional and/or national solutions also have a major role to play.

The findings reviewed here underscore the urgent need to translate improved scientific understanding into improved policymaking and action. As science targets opportunities for better progress, decision makers can more effectively use this information to address environmental challenges and thereby improve conditions for all life on earth.