This book defends a cosmopolitan ethic, that of biocentric consequentialism, and applies it to a range of global environmental issues (e.g. resources, population, biodiversity loss) and policies (e.g.sustainable development, population policies, biodiversity preservation.) It also applies this ethic to global justice, international order, intergenerational equity, decision-making, models of agency and global citizenship. It thus supplies an ethical critique of current international environmental problems and negotiations, and the shape which international regimes will need in order to cope with global environmental problems.