Today, our planet carries over seven billion people. Yet its capacity to provide for each one of these individuals is threatened by population growth, climate change, deforestation, collapse of fisheries, desertification, air pollution and scarcity of fresh water. The full extent of our shared global environmental problems goes far beyond the well-publicised challenge of global climate change (or global warming). In fact, one of the elements often forgotten is the complicated relationship between human beings and their environment. In the early years of the conversation around environmental protection, some argued that the planet’s resources were there for our collective consumption. However, there are limits to growth and this raises a range of important issues for international relations. Our population quadrupled between 1900 and 2000. This growth, coupled with abrupt climate change events and further compounded by rapid industrialisation and fast urban expansion, have combined into a perfect storm of negative environmental processes that put pressure on the capacity of Planet Earth to sustain life. As students of IR, we ought to recognise that the environment is one of the areas where much work remains to be done, particularly because cooperative approaches to environmental protection have had a very mixed record despite the grave implications of failure.