RECENT INNOVATIONS IN EARTH SYSTEM science have added compelling arguments for the integration of environmental matters into security policy. Concerns about scarcity in the global South and conflicts over resources are now being overtaken by worries about global climate change and the vulnerabilities of populations to ecological disruptions. The sheer scale of human activity has lead to the designation of the contemporary era as a new geological period-the "Anthropocene"-in which ecological disruptions and vulnerabilities are caused increasingly by human actions. Thus, security planning needs to emphasize the importance of reducing the total throughput of materials and energy in the biosphere to limit disruptions while simultaneously building resilience and habits of international cooperation into human societies to better cope when disaster strikes.
Initial debates about global environmental problems in the 1970s focused on population growth, endangered species, toxic chemical pollution, and various resource shortages. As the cold war drew to an end, many of these themes reemerged in international politics as they related to environmental security, water wars, and the potential for scarcity-induced conflict. As climate change now focuses attention on matters of environment, security is once again linked to the discussion, but the earlier environmental focus on toxic pollution, preservation of non-human species, and resource shortages is now being supplemented by a larger understanding of humanity as endangered by its changing ecological context. Recent developments in earth system science provide compelling reasons to update the earlier discussion and reconsider how we now think about global security.
Unlike early environmental security research, which was concerned that scarcities in the global South might cause wars between the North and South, subsequent work has made clear that such a situation is not very likely.1 More plausible dangers lie in potential civil wars in the South over the control of the rent streams from relatively abundant resources rather than from environmental scarcity, and from the depredations of political elites rather than from the poverty of marginal peoples.2 As the prospect of "peak oil" looms once again, these matters of resources and conflict are being discussed in geopolitical terms.3 Most recendy, and especially in the aftermath of the severe hurricane season of 2005, new questions are being asked about human vulnerabilities as a result of climate change.
Growing concern over human vulnerability corresponds to the shift in the earth sciences over the last decade. Science has enabled us to recognize that we live in a single, interconnected biosphere, one that humanity is changing as it becomes an urban species increasingly powered by fossil fuels. Earlier environmental concerns regarding the dangers of industrial pollution, the need for resource and wildlife conservation, and even Malthusian concerns about population are being overtaken by a global perspective that emphasizes the ecological connections among phenomena and between humanity and its environment.
The sheer scale of human activity is changing the biosphere in quite dramatic ways. The much-quoted line from Genesis about humanity having dominion over nature can now simply be read as a statement of fact.4 The world is effectively no longer "wild." But, in "conquering nature," we have fundamentally changed it through urban industry, such that the categorical distinctions between humanity and nature are no longer very useful in discussing either the future or how we might arrange social and political matters.5 The artificial habitat we are collectively constructing-often inadvertently-is now the appropriate context for environmental security discussions.
This scientific update should be incorporated into security thinking. Such an approach starts with a summary of the Andiropocene era and then reflects on the intellectual limitations of contemporary security concepts in application to new earth-systems thinking. …