ous situations are those that combine high water stress and state fragility.
Some historical analysis suggests that societies can be very slow to act upon strong signals from environmental change, resulting in breakdowns that, from a historical vantage, are shocking (e.g., Diamond, 2004). The frequency with which breakdowns occur due to environmental stress have led some analysts to argue that societies should consider carefully how they will rebuild (Homer-Dixon, 2006).
Even in the absence of catastrophic events, existing water management institutions and treaty arrangements would need to evolve in order for cooperation to be a more likely outcome than conflict. The web of economic and social relationships in the region has become increasingly complex and intricate, and the numbers of stakeholders and interested parties in water resource management have multiplied. This creates new sets of challenges for governance and stability International treaties may also have to adopt a more integrated ecological approach so that water issues are not considered in isolation from the management of land, energy, and other resources. This creates a greater role for scientific knowledge and makes international collaboration on scientific issues all the more important.
More generally, regional—as opposed to bilateral— frameworks for resource management may become increasingly necessary (and if robust regional governance mechanisms emerge, then new forms of early warning and response will become possible). Historically, large regional powers throughout the world have tended to favor bilateral arrangements, which have been the norm, while small and medium powers have enjoyed greater leverage within multilateral institutions (see Naidu  and Singh  for a discussion of the shift in India’s position in favor of multilateralism). Moving forward, however, as countries such as India play a more prominent role on the world stage, they may be increasingly willing to embrace regional and multilateral arrangements and try, to the extent possible, to structure these institutions to their advantage.
Key features of the environmental security of the HKH region were identified at the workshop by the breakout groups on Demography and Security and Risk Factors and Vulnerabilities. Starting from those concepts, the Committee used its expert judgment, reviews of the literature, and deliberation to develop the following conclusions:
• Natural disasters in South Asia involve meteorological, hydrological, and geophysical phenomena that are not unique to the HKH region. Current efforts that focus on these natural hazards and disaster reduction in South Asia can offer useful lessons when considering and addressing the potential for impacts resulting from changes in snowmelt processes and glacial retreat in the region.
• Current international datasets indicate that over the past century, natural disasters in the region have been flood-dominated in terms of the frequency of events and number of people affected. However, the number of people killed over the past century by natural disasters was dominated by droughts and related famines. Over the past 30-year period the patterns and trends are less clear. Floods have had increasing significance in the numbers of people affected, while earthquakes have been associated with the highest number of people killed.
• Modernization and globalization may reduce losses of life and long-term macroeconomic impacts of disasters, but they can also increase the numbers of people affected and the economic damages.
• At the regional level of disaster management, organizations give particular emphasis to international cooperation, information sharing, and capacity building, as well as an increasing emphasis on linking climate change with disaster risk reduction. At the national and state levels, processes of devolution or centralization over time can affect disaster response. An increased focus on vulnerability and resilience within the disaster research community could lead to improved disaster management.
• Changes in transboundary water flows can generate or increase conflicts of interest among riparian countries, and these climate-induced changes will further complicate changes driven by economic, demographic, and political factors.
• Among the most serious challenges, even in the absence of climate change, are the magnitude of conflicting demands for limited water resources, the lack of corresponding institutional capacity to cope