cause sufficient harm to human well-being to create humanitarian crises, political violence, or other issues of security concern are among the most prominently cited in the reports on climate change and security that have appeared in recent years from U.S. government security agencies and the foreign and security policy community. Such vulnerability-based scenarios predominated among the sponsor’s concerns in requesting this study and in the early deliberations of the committee in open session with the sponsor present. The committee decided at the outset that these concerns provided the most appropriate focus for its work, as is discussed in further detail when the conceptual framework is presented in Chapter 2.
We acknowledge that with this focus, this study sets aside some climate–security connections that could prove highly significant and that deserve further study and analysis. These include some potential threats already noted, such as from extreme climate events that may impede the ability of U.S. military organizations to perform their missions and from conflict over natural resources and sea lanes in Arctic regions that may become newly accessible as a result of the melting of sea ice (cf., National Research Council, 2011b).
Another important class of security risks that are excluded from this study is those that may arise from policy responses to the anticipation or experience of disruptive climate events. Several plausible security risk scenarios begin with policies to limit climate change. For example, the expanded use of nuclear power in some countries to replace fossil fuels could increase risks of nuclear proliferation. Some policies to increase biofuel production could contribute to food price spikes and thus reduce effective food availability to low-income populations around the world. A single country’s decision to counter global warming by geoengineering, perhaps by fertilizing the ocean to grow photosynthetic organisms or by injecting sulfate particles into the stratosphere, could create conflict with other countries. Several other policy-based scenarios begin with a country’s efforts to protect itself from the expected consequences of climate change in ways that could disrupt international relations. For example, an upstream country might impound water from a river to guard against drought and thus reduce water supplies for its downstream neighbors. Or one country might purchase land in another country to produce food for its domestic consumption, creating conflict if a future food shortage hits the country where the food is being produced for export.
A number of threat scenarios of the above types are mentioned in previous climate–security analyses. Although some of them could have significant security consequences, they have not been treated as primary concerns in these reports. We have focused more narrowly on situations in which direct harm from climate events affecting vulnerable places or critical life-supporting systems could play a driving role in events of security