Challenges of adapting to a changing climate.

• Author: Hurd, Brian H.

1. INTRODUCTION II. IDENTIFYING CLIMATE CHANGE VULNERABILITY AND IMPACTS AND DESCRIBING APPROACHES TO ADAPTATION III. SETTING THE STAGE WITH SOME USEFUL DEFINITIONS IV. BUILDING ADAPTIVE CAPACITY: WHAT, HOW, AND WHERE TO BEGIN? A. Improve scientific capabilities and research B. Develop appropriate risk management institutions and policies C. Increase use of market-based programs for resource management D. Add flexibility and safety to long-lived infrastructure design and improvements E. Consider climatic factors in land use planning and building codes V. TIMING INVESTMENT AND POLICY CHANGES VI. CLOSING THOUGHTS "Organizations increasingly face adaptive challenges requiring them to abandon the familiar and routine. Instead, they need to develop the capacity to harness knowledge and creativity to fashion unique responses, stimulate organizational learning and sometimes embrace transformational change."

   Carl Sussman (Management and Community Development Consultant), (1)

1. INTRODUCTION

   The consensus among many climate scientists is that reducing greenhouse gas (GHG) emissions from current levels can be expected to slow and, eventually, lower atmospheric concentrations if efforts are sufficiently aggressive. Over time, reduced GHG emissions and concentrations will lessen both the likelihood and the severity of adverse climatic changes and impacts. (2) Recent trends and observations indicate that warmer temperatures and hydrologic changes associated with elevated GHG levels may already be occurring. These changes are likely to endure for some period, even beyond the time when emissions are reduced, because of the longevity of the atmospheric carbon cycle--about thirty years. (3) As a consequence, measurable warming and hydrologic changes are likely unavoidable--at least for the remainder of the century. Faced with this prospect, communities, organizations, and institutions that are particularly vulnerable to warming and hydrologic changes might prudently consider strategies that will enhance adaptive capacity. Such adaptive strategies could potentially forestall or limit adverse impacts and, in some cases, harness new and changing opportunities for economic growth and development. (4)

   This paper intends to provide a non-technical overview that describes several key concepts and issues related to climate change adaptation. Drawing insights from varied studies, including those on climate change impacts, vulnerability assessment, and adaptation capacity building, the paper focuses on strategies to bolster adaptive capacity within societal systems. In order to illustrate the concepts of adaptation, the paper utilizes the projected changes in water resources as an illustrative example. In addition, the paper also identifies strategies and projects that are general starting points for efforts to build adaptive capacity. These strategies are attractive starting points because they offer benefits beyond those stemming from climate change preparedness and can be characterized as "no regrets" or "win-win" tactics. For example, additional research into the management and technology associated with water use could potentially raise water-use efficiencies, and thus provide benefits for regions experiencing long-run drought and increased water demands, independent of climate change. These additional benefits, thus, effectively lower the action threshold for project implementation. Finally, the paper turns toward the critical issues of timing adaptation projects and policy changes. Uncertainty about the timing, location, and severity of climate change impacts introduces complexity into both the decision-making process and the traditional rules for optimal investment timing.

2. IDENTIFYING CLIMATE CHANGE VULNERABILITY AND IMPACTS AND DESCRIBING APPROACHES

   TO ADAPTATION

   Rising concentrations of greenhouse gases in the atmosphere are widely believed by climate scientists to contribute to warmer temperatures, rising sea levels, decreasing snow packs, earlier snowmelts, and changing spatial and temporal patterns of rainfall. (2) Such changes can have many significant and profound impacts on the functioning of many vulnerable systems found within communities, institutions, and ecosystems. (5)

   Accurately characterizing the range of possible impacts--both economic and non-economic--on various systems and resources is complicated by uncertainty about the magnitude, rate, and nature of climate changes, as well as uncertainty about the nature and timing of adaptive responses and their subsequent feedback on impacts. Adaptations are designed to alter and affect the type and magnitude of impacts. Therefore, understanding and portraying likely adaptive responses is fundamental to the assessment and projection of impacts. For example, the earliest climate change studies that attempted to measure potential impacts on agricultural systems made strong assumptions about the behavior of farmers. These studies, driven largely by the biophysical crop data that was available, assumed that farmers would act naively by failing to adjust their practices even in the face of observed changing conditions. (6) These so-called myopic or naive farmer assumptions provided for "worst-case-scenario" estimates that did not require researchers to guess about farmer behavior. However, in spite of these limitations, the studies did yield some insights about the range and the upper-bound magnitude of economic impacts and the regional distribution of potential impacts. (7)

   Perhaps even more importantly, these studies uncovered the necessity of including adaptation in the measurement process. Researchers had to move beyond the question of whether farmers (or people in other vulnerable sectors) would adapt to questions about how, when, and where they would adapt, the degree of effectiveness of the adaptations, and how to best portray adaptations in subsequent impact models.

3. SETTING THE STAGE WITH SOME USEFUL DEFINITIONS

   To better understand the context and role that underlies the processes of adapting to climate changes, it is helpful to define the following terms:

   Sensitivity describes how climate changes can affect a system and its ability to function. Consider an agricultural example--as compared to wheat, corn is much more physiologically sensitive to climate change because corn is more susceptible to hot and dry conditions and is less able to take advantage of higher carbon dioxide (C[O.sub.2]) levels. Exposure describes the extent of climate-change sensitive resources or societal systems that are potentially at risk. It is a critical element of vulnerability, and is one that is often influenced by institutions and...