constitute a threat to water and food security and/or political stability?

OPTIONS FOR ADAPTING TO
CHANGES IN CLIMATE, HYDROLOGY,
AND WATER AVAILABILITY

There are some potential adaptations that governments, communities, or individuals may consider in response to climate change’s effects on the hydrologic system. Even with significant international progress toward mitigating greenhouse gas emissions, with current levels of carbon dioxide and other greenhouse gases in the atmosphere, there will be significant climate change over the next few decades, and thus some adaptation, particularly to strengthen water management systems, will be necessary.

It can be difficult to make decisions about which adaptation strategies to pursue in the face of uncertainty about the magnitude of climate change’s hydrological impacts. Also, there are significant uncertainties about the effectiveness of various adaptation options. Some adaptation options have been shown to be effective in adapting to variability under current climatic conditions, but it is not known whether they will hold up under a changing climate (NRC, 2010a). Additionally, implementation of adaptation strategies can be challenging in developed countries:

Numerous attempts have been made to develop and implement adaptive management strategies in environmental management, but many of them have not been successful, for a variety of reasons, including lack of resources, unwillingness of decision makers to admit to and embrace uncertainty; institutional, legal, and political preferences for known and predictable outcomes; the inherent uncertainty and variability of natural systems; the high cost of implementation; and the lack of clear mechanisms for incorporating scientific findings into decision making. Despite all of the above challenges, often there is no better option for implementing management regimes…. (NRC, 2011b)

And developing countries are likely to face as many challenges.

Good first adaptation strategies to pursue are generally flexible (i.e., they do not lock a country or other entity into a long-term commitment to the strategy), are relatively low-cost and are “no regret” strategies (i.e., they would be good strategies to take regardless of how severe climate change’s impacts become). In general, many strategies that encourage good management of water resources under current climate could serve as useful adaptation strategies in a world with altered climate. Similarly, because people with fewer resources are often more vulnerable to climate change disruptions, many strategies that promote sustainable economic development could also be useful adaptation strategies in the face of climate change.

There is a large literature on the topic of adaptation, and the Committee can only briefly describe a few potential adaptation options in this section. Adaptation was discussed previously in the context of water management institutions and disaster agencies in Chapters 3 and 4, respectively. Here, the Committee describes options that affect the supply or timing of water available to users, followed by options that affect the demand of water by users. Then the Committee discusses integrated watershed management and river basin management, which often consider both supply and demand. Finally, the Committee discusses adaptation options to decrease the risk of negative impacts from flooding.

Adapting Under Uncertainty: The Need to Monitor

As discussed above, and throughout this report, lack of understanding and a paucity of data about current and emerging conditions of glacial melt and the hydrological system more generally are major sources of uncertainty in the region. Adaptive management1 of water resources depends critically on observations of changes that are occurring. Therefore, adaptation options will rely on expanding the monitoring programs in the region, including increased hydrometeorological data; measurements of glacial mass balances, seasonal snow cover, black carbon on snow and ice; assessment of GLOF risks; streamflow data (i.e., discharge); water quality; and demographic patterns of water use. Both remotely sensed and in situ data are valuable for such monitoring programs (USAID, 2010).

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1 Adaptive management is a flexible approach designed to meet management goals under a variety of future climate conditions and requires a nonstationary view (e.g., Milly et al., 2008; NRC, 2010a, 2012b).



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