Kathleen A. Miller

The implications of projected climate change for freshwater resources and their management

A review of the implications of climate change for freshwater resources, based on Chapter 4 of Working Group 2, IPCC.

High resolution coupled climate-runoff simulations of seasonal snowfall over Colorado: A process study of current and warmer climate

AbstractClimate change is expected to accelerate the hydrologic cycle, increase the fraction of precipitation that is rain, and enhance snowpack melting. The enhanced hydrological cycle is also expected to increase snowfall amounts due to increased moisture availability. These processes are examined in this paper in the Colorado Headwaters region through the use of a coupled high-resolution climate–runoff model. Four high-resolution simulations of annual snowfall over Colorado are conducted. The simulations are verified using Snowpack Telemetry (SNOTEL) data. Results are then presented regarding the grid spacing needed for appropriate simulation of snowfall. Finally, climate sensitivity is explored using a pseudo–global warming approach. The results show that the proper spatial and temporal depiction of snowfall adequate for water resource and climate change purposes can be achieved with the appropriate choice of model grid spacing and parameterizations. The pseudo–global warming simulations indicate enha...

WATER ALLOCATION IN A CHANGING CLIMATE: INSTITUTIONS AND ADAPTATION

Global warming may profoundly affect temporal and spatial distributions of surface water availability. While climate modelers cannot yet predict regional hydrologic changes with confidence, it is appropriate to begin examining the likely effects of water allocation institutions on societys adaptability to prospective climate change. Such institutions include basic systems of water law, specific statutes, systems of administration and enforcement, and social norms regarding acceptable water-use practices. Both climate and the changing nature of demands on the resource have affected the development and evolution of water allocation institutions in the United States. Water laws and administrative arrangements, for example, have adapted to changing circumstances, but the process of adaptation can be costly and subject to conflict. Analysis of past and ongoing institutional change is used to identify factors that may have a bearing on the costliness of adaptation to the uncertain impacts of global warming on water availability and water demands. Several elements are identified that should be incorporated in the design of future water policies to reduce the potential for disputes and resource degradation that might otherwise result if climate change alters regional hydrology.

Climate Change and Resource Management in the Columbia River Basin

Abstract Scenarios of global climate change were examined to see what impacts they might have on transboundary water management in the Columbia River basin. Scenario changes in natural streamflow were estimated using a basin hydrology model. These scenarios tended to show earlier seasonal peaks, with possible reductions in total annual flow and lower minimum flows. Impacts and adaptation responses to the natural streamflow scenarios were determined through two exercises: (a) estimations of system reliability using a reservoir model with performance measures and (b) interviews with water managers and other stakeholders in the Canadian portion of the basin. Results from the two exercises were similar, suggesting a tendency towards reduced reliability to meet objectives for power production, fisheries, and agriculture. Reliability to meet flood control objectives would be relatively unchanged in some scenarios but reduced in others. This exercise suggests that despite the high level of development and management in the Columbia, vulnerabilities would still exist, and impacts could still occur in scenarios of natural streamflow changes caused by global climate change. Many of these would be indirect, reflecting the complex relationship between the region and its climate.

Climate and Cooperation: A New Perspective on the Management of Shared Fish Stocks

Climate regime shifts occur at irregular intervals and have profound and persistent impacts on ocean temperature and circulation patterns and on the dynamics of marine fish populations. Despite a growing scientific literature and some attention to the implications of such regime shifts for domestic fisheries, the issue has received little attention in the context of international fishery management. This paper presents evidence for the significance of climatic regime shifts, and draws upon the recent history of conflict between Canada and the United States over Pacific salmon management to illustrate the dangers that unpredicted, unanticipated environmental regime shifts pose for efforts to maintain international cooperation. This suggests a need for greater attention to this issue. Fishery agreements can be made more resilient to the impacts of such environmental changes by explicitly building in flexibility — for example, by allowing the use of side payments. In addition, pre-agreements on procedures to be followed in the event of sustained changes in fish stock productivity or migration patterns, and cooperation on developing common scientific understandings, can help to prevent destructive conflicts. Finally, the literature employing game theoretic shared-fishery models could be further developed to focus on providing practical guidance for maintaining cooperation in the presence of unpredictable and persistent environmental changes.

The freeze risk to Florida citrus. Part II. Temperature variability and circulation patterns

Abstract Severe freezes are a serious problem for the citrus growers of central Florida. To investigate possible climatic causes of intermittent freezes, this paper examines the influence of several atmospheric circulation patterns on winter temperatures in Florida. The Pacific/North American pattern is shown to be particularly influential and the North Atlantic Oscillation also to be significant, while the Southern Oscillation does not show a direct effect. A decreasing trend in Florida winter temperatures since 1947 can be explained by fluctuations in the former two circulation patterns. Climate model studies to investigate possible changes in the frequency or location of these circulation patterns could suggest potential changes in the freeze risk associated with climatic change.

Wildfire Risk and Climate Change: The Influence on Homeowner Mitigation Behavior in the Wildland–Urban Interface

This project examines the sensitivity of behavior and attitudes regarding wildfire risk to perceptions of drought and climate change impacts, and documents the current state of homeowner risk mitigation effort in Clear Creek County, Colorado. Survey results demonstrate that homeowners have a fairly accurate understanding of the impact of climate change and other environmental risk factors, and that the majority have undertaken the most obvious risk mitigation investments, such as pruning vegetation around the home. Perception of climate and weather as risk factors has a significant impact on risk perception and concern about wildfire but is not a determinant of advanced mitigation effort. Further mitigation effort primarily relates to the value homeowners place on amenities associated with their house and their perception of the impact of neighboring lands mitigation.

Pacific Salmon Fisheries: Climate, Information and Adaptation in a Conflict-Ridden Context

Pacific Salmon are anadromous fish that cross state and international boundaries in their oceanic migrations. Fish spawned in the rivers of one jurisdiction are vulnerable to harvest in other jurisdictions. The rocky history of attempts by the United States and Canada to cooperatively manage their respective salmon harvests suggests that such shared resources may present difficult challenges for effective adaptation to climate change. On June 30, 1999, the two nations signed an agreement which, if successfully implemented, may end several years of rancorous conflict. For the previous six years, they had been unable to agree on a full set of salmon fishing regimes under the terms of the Pacific Salmon Treaty. This conflict was sparked by strongly divergent trends in the abundance of northern and southern salmon stocks, and a consequent change in the balance of each nations interceptions of salmon spawned in the other nations rivers. The trends are attributable, in part, to the effects of large-scale climatic fluctuations. This case demonstrates that it may not be a simple matter to respond effectively to a climate change. Adaptation is difficult when a resource is exploited by multiple competing users who possess incomplete information. If, in addition, their incentives to cooperate are disrupted by the impacts of the climatic variation, dysfunctional breakdowns in management rather than efficient adaptation may ensue. Institutional factors will determine the extent to which the management of such resources can adapt effectively to climate variability or long-term climate change.

Water resource management and climate change adaptation: a holistic and multiple criteria perspective

Anthropogenic climate change is likely to significantly increase human exposure to droughts and floods. It will also alter seasonal patterns of water availability and affect water quality and the health of aquatic ecosystems with various implications for social and economic wellbeing. Policy development for water resource adaptation needs to allow for a holistic and transparent analysis of the probable consequences of policy options for the wide variety of water uses and users, and the existing ecosystem services associated with any stream basin. This paper puts forward an innovative methodological framework for planning development-compatible climate policies drawing on multi-criteria decision analysis and an implicit risk-management approach to the economics of climate change. Its objectives are to describe how the generic methodology could be tailored for analysis of long-range water planning and policy options in developing countries, and to describe the place of climate change considerations in water governance and planning processes. An experimental thought-exercise applying the methodology to water policy development in Yemen provides further insights on the complexity of water adaptation planning. It also highlights the value of conducting sensitivity analysis to explore the implications of multiple climate scenarios, and the importance of accounting for policy portfolios rather than individual policy options. Rather than constituting a tool that can generate clear measures of optimal solutions in the context of adaptation to uncertain climate futures, we find that this approach is best suited to supporting comprehensive and inclusive planning processes, where the focus is on finding socially acceptable paths forward.

Climate and economic competitiveness: Florida freezes and the global citrus processing industry

SummaryCasual observers of the impacts associated with four recent freezes in Floridas citrus producing areas might be inclined to agree with an assessment by Miami Herald reporters that these freezes had caused the ‘king of citrus’ to be toppled from its throne, enabling Brazil to take its place. Research on the citrus industry, however, reveals that the impacts of these recent freezes only explain part of the story of the interaction between climate variability and the relationship between the citrus industries of Florida and Brazil. Climate characteristics and their variability have directly as well as indirectly affected the economic competitiveness of citrus producers whose output is in large measure climate-dependent. Climate variability has had direct impacts on Floridas citrus industry by adversely affecting the productivity of citrus groves in some areas, by altering growers perceptions of freeze probabilities and, occasionally, by suddenly reducing output, thus elevating the price that consumers must pay for that commodity. Indirectly, competition can be affected by climate as a potential producer identifies a weakness in the supply system of an existing industry and seeks to ‘fill the gap’.Brazils involvement in the toppling of ‘King Citrus’ began not in the early 1980s (as a result of the four freezes in the past six years), but in 1962 as a result of a major freeze in that year, one that sharply increased FCOJ prices by reducing Floridas output. It was then that the climate had an impact on the economic competitiveness of the citrus industry. The records document the steady, almost meteoric, rise in Brazilian FCOJ production and exports. Subsequent freezes only served to abet a process that had been well underway two decades before the recent devastating freezes.As for Floridas ability to continue and perhaps expand its key role in the global citrus economy, the recent freezes do not appear to have fatally damaged that. Rather, those freezes have reawakened Floridas citrus producers to the fact that they are involved in a climate-sensitive industry and have reminded them that the potential for freeze-related problems is never far away. That reawakening has sparked interest in developing hardier citrus varieties, more effective freeze protection methods, and better ways to hedge economically against freeze impacts to the industry.