now exceeds global terrestrial production of reactive nitrogen. Without artificial fertilizers there would not be enough food to sustain a population of seven billion people. These changes to the human sub-system have a direct influence on all components of the Earth system. The chemical composition of the atmosphere has changed significantly. Concentrations of important greenhouse gases, carbon dioxide, methane and nitrous oxide are rising fast. Over Antarctica a large hole in the ozone layer appeared. Fisheries collapsed: most of the world's fisheries are now fully or over-exploited. Thirty percent of tropical rainforests disappeared. In 2000, Nobel prize-winning scientist Paul Crutzen announced the scale of change is so great that in just 250 years, human society has pushed the planet into a new geological era: the Anthropocene. This name has stuck and there are calls for the Anthropocene to be adopted officially. If it is, it may be the shortest of all geological eras. Evidence suggests that if human activities continue to change components of the Earth system, which are all interlinked, this could heave the Earth system out of one state and into a new state. Society Global change in a societal context encompasses social, cultural, technological, political, economic and legal change. Terms closely related to global change and society are globalization and global integration. Globalization began with long-distance trade and urbanism. The first record of long distance trading routes is in the third millennium BC. Sumerians in Mesopotamia traded with settlers in the Indus Valley, in modern-day India. Since 1750, but more significantly, since the 1950s, global integration has accelerated. This era has witnessed incredible global changes in communications, transportation, and computer technology. Ideas, cultures, people, goods, services and money move around the planet with ease. This new global interconnectedness and free flow of information has radically altered notions of other cultures, conflicts, religions and taboos. Now, social movements can and do form at a planetary scale. Evidence, if more were needed, of the link between social and environmental global change came with the 2008-2009 global financial crisis. The crisis pushed the planet's main economic powerhouses, the United States, Europe and much of Asia into recession. According to the Global Carbon Project, global atmospheric emissions of carbon dioxide fell from an annual growth rate of around 3.4% between 2000 and 2008, to a growth rate of about 2% in 2008. Planetary management Humans are altering the planet's biogeochemical cycles