Hurricane Sandy and adaptation pathways in New York: Lessons from a first-responder city

Two central issues of climate change have become increasingly evident: Climate change will significantly affect cities; and rapid global urbanization will increase dramatically the number of individuals, amount of critical infrastructure, and means of economic production that are exposed and vulnerable to dynamic climate risks. Simultaneously, cities in many settings have begun to emerge as early adopters of climate change action strategies including greenhouse gas mitigation and adaptation. The objective of this paper is to examine and analyze how officials of one city – the City of New York – have integrated a flexible adaptation pathways approach into the municipality's climate action strategy. This approach has been connected with the City's ongoing response to Hurricane Sandy, which struck in the October 2012 and resulted in damages worth more than US$19 billion. A case study narrative methodology utilizing the Wise et al. conceptual framework (see this volume) is used to evaluate the effectiveness of the flexible adaptation pathways approach in New York City. The paper finds that Hurricane Sandy serves as a “tipping point” leading to transformative adaptation due to the explicit inclusion of increasing climate change risks in the rebuilding effort. The potential for transferability of the approach to cities varying in size and development stage is discussed, with elements useful across cities including the overall concept of flexible adaptation pathways, the inclusion of the full metropolitan region in the planning process, and the co-generation of climate-risk information by stakeholders and scientists.     

The potential impacts of sea level rise on the coastal region of New Jersey,USA

This study presents an assessment of the potential impacts of sea level rise on the New Jersey, USA coastal region. We produce two projections of sea level rise for the New Jersey coast over the next century and apply them to a digital elevation model to illustrate the extent to which coastal areas are susceptible to permanent inundation and episodic flooding due to storm events. We estimate future coastline displacement and its consequences based on direct inundation only, which provides a lower bound on total coastline displacement. The objective of this study is to illustrate methodologies that may prove useful to policy makers despite the large uncertainties inherent in analysis of local impacts of climate and sea level change. Our findings suggest that approximately 1% to 3% of the land area of New Jersey would be permanently inundated over the next century and coastal storms would temporarily flood low-lying areas up to 20 times more frequently. Thus, absent human adaptation, by 2100 New Jersey would experience substantial land loss and alteration of the coastal zone, causing widespread impacts on coastal development and ecosystems. Given the results, we identify future research needs and suggest that an important next step would be for policy makers to explore potential adaptation strategies.     

Assessing municipal vulnerability to predicted sea level rise: City of Satellite Beach, Florida

In the fall of 2009 the City of Satellite Beach (City), Florida, authorized a study designed to assess municipal vulnerability to rising sea level and facilitate discussion of potential adaptation strategies. The project is one of the first in Florida to seriously address the potential consequences of global sea level rise, now forecast to rise a meter or more by the year 2100. Results suggest the tipping point between relatively benign impacts and those that disrupt important elements of the municipal landscape is +?2 ft (0.6 m) above present. Seasonal flooding to an elevation of +?2 ft is forecast to begin around 2050 and thus the City has about 40 years to formulate and implement an adaptation plan. As an initial step, the Comprehensive Planning Advisory Board, a volunteer citizen committee serving as the City??s local planning authority, has recommended a series of updates and revisions to the City??s Comprehensive Plan. If approved by the City Council and Florida??s Department of Community Affairs, the amendments will provide a legal basis for implementing specific policies designed to reduce the City??s vulnerability to sea level rise.     

A simple technique for estimating an allowance for uncertain sea-level rise

Projections of climate change are inherently uncertain, leading to considerable debate over suitable allowances for future changes such as sea-level rise (an ??allowance?? is, in this context, the amount by which something, such as the height of coastal infrastructure, needs to be altered to cope with climate change). Words such as ??plausible?? and ??high-end?? abound, with little objective or statistically valid support. It is firstly shown that, in cases in which extreme events are modified by an uncertain change in the average (e.g. flooding caused by a rise in mean sea level), it is preferable to base future allowances on estimates of the expected frequency of exceedances rather than on the probability of at least one exceedance. A simple method of determining a future sea-level rise allowance is then derived, based on the projected rise in mean sea level and its uncertainty, and on the variability of present tides and storm surges (??storm tides??). The method preserves the expected frequency of flooding events under a given projection of sea-level rise. It is assumed that the statistics of storm tides relative to mean sea level are unchanged. The method is demonstrated using the GESLA (Global Extreme Sea-Level Analysis) data set of roughly hourly sea levels, covering 198 sites over much of the globe. Two possible projections of sea-level rise are assumed for the 21st century: one based on the Third and Fourth Assessment Reports of the Intergovernmental Panel on Climate Change and a larger one based on research since the Fourth Assessment Report.     

Global warming and hurricanes: the potential impact of hurricane intensification and sea level rise on coastal flooding

Tens of millions of people around the world are already exposed to coastal flooding from tropical cyclones. Global warming has the potential to increase hurricane flooding, both by hurricane intensification and by sea level rise. In this paper, the impact of hurricane intensification and sea level rise are evaluated using hydrodynamic surge models and by considering the future climate projections of the Intergovernmental Panel on Climate Change. For the Corpus Christi, Texas, United States study region, mean projections indicate hurricane flood elevation (meteorologically generated storm surge plus sea level rise) will, on average, rise by 0.3 m by the 2030s and by 0.8 m by the 2080s. For catastrophic-type hurricane surge events, flood elevations are projected to rise by as much as 0.5 m and 1.8 m by the 2030s and 2080s, respectively.     

California coastal management with a changing climate

With over 2,000 miles (3,218 km) of ocean and estuarine coastline, California faces significant coastal management challenges as a result of climate change-induced sea level rise. Under high emission scenarios, recent models predict 1.4 m or more of sea level rise by 2100, accompanied by increasing storm surges. This article investigates the most important issues facing coastal managers, explores the policy tools available for adapting to the impacts of climate change, assesses institutional constraints to adaptation, and identifies priorities for future research and policy action. We find that adaptation tools exist for dealing with anticipated increases in coastal erosion and flooding, but they involve significant costs and tradeoffs. In particular, coastal armoring, such as seawalls, can protect developed coastal lands, but destroys beaches and habitat. Although California already has policies and institutions that aim to balance the competing objectives for coastal development, management agencies are at the early stages of understanding how to facilitate adaptation. Research priorities to inform coastal adaptation planning include: (i) inventorying coastal resources to provide a firmer basis for balancing decisions on property and habitat protection, (ii) identifying opportunities for coastal habitat migration, (iii) assessing the vulnerabilities of existing and planned coastal infrastructure, and (iv) experimenting with alternatives to armoring as a way of managing the changing coastline.     

A megacity in a changing climate: the case of Kolkata

Projections by the Intergovernmental Panel on Climate Change suggest that there will be an increase in the frequency and intensity of climate extremes in the 21st century. Kolkata, a megacity in India, has been singled out as one of the urban centers vulnerable to climate risks. Modest flooding during monsoons at high tide in the Hooghly River is a recurring hazard in Kolkata. More intense rainfall, riverine flooding, sea level rise, and coastal storm surges in a changing climate can lead to widespread and severe flooding and bring the city to a standstill for several days. Using rainfall data, high and low emissions scenarios, and sea level rise of 27 cm by 2050, this paper assesses the vulnerability of Kolkata to increasingly intense precipitation events for return periods of 30, 50, and 100 years. It makes location-specific inundation depth and duration projections using hydrological, hydraulic, and urban storm models with geographic overlays. High resolution spatial analysis provides a roadmap for designing adaptation schemes to minimize the impacts of climate change. The modeling results show that de-silting of the main sewers would reduce vulnerable population estimates by at least 5 %.     

Coping with climate variability and climate change in La Ceiba,Honduras

La Ceiba, Honduras, a city of about 200,000 people, lies along the Caribbean Sea, nestled against a mountain range and the Rio Cangrejal. The city faces three flooding risks: routine flooding of city streets due to the lack of a stormwater drainage system; occasional major flooding of the Rio Cangrejal, which flows through the city; and flooding from heavy rainfall events and storm surges associated with tropical cyclones. In this study, we applied a method developed for the U.S. Agency for International Development and then worked with stakeholders in La Ceiba to understand climate change risks and evaluate adaptation alternatives. We estimated the impacts of climate change on the current flooding risks and on efforts to mitigate the flooding problems. The climate change scenarios, which addressed sea level rise and flooding, were based on the Intergovernmental Panel on Climate Change estimates of sea level rise (Houghton et al. 2001) and published literature linking changes in temperature to more intense precipitation (Trenberth et al., Bull Am Meteorol Soc, 84:1205–1217, 2003) and hurricanes (Knutson and Tuleya, J Clim, 17:3477–3495, 2004). Using information from Trenberth et al., Bull Am Meteorol Soc, 84:1205–1217, (2003) and Knutson and Tuleya, J Clim, 17:3477–3495, 2004, we scaled intense precipitation and hurricane wind speed based on projected temperature increases. We estimated the volume of precipitation in intense events to increase by 2 to 4% in 2025 and by 6 to 14% by 2050. A 13% increase in intense precipitation, the high scenario for 2050, could increase peak 5-year flood flows by about 60%. Building an enhanced urban drainage system that could cope with the estimated increased flooding would cost one-third more than building a system to handle current climate conditions, but would avoid costlier reconstruction in the future. The flow of the Rio Cangrejal would increase by one-third from more intense hurricanes. The costs of raising levees to protect the population from increased risks from climate change would be about $1 million. The coast west of downtown La Ceiba is the most vulnerable to sea level rise and storm surges. It is relatively undeveloped, but is projected to have rapid development. Setbacks on coastal construction in that area may limit risks. The downtown coastline is also at risk and may need to be protected with groins and sand pumping. Stakeholders in La Ceiba concluded that addressing problems of urban drainage should be a top priority. They emphasized improved management of the Rio Cangrejal watershed and improved storm warnings to cope with risks from extreme precipitation and cyclones. Adoption of risk management principles and effective land use management could also help reduce risks from current climate and climate change.     

气候变化对陆地生态系统和海岸带地区的影响解读

IPCC第五次评估报告认为,受气候变化影响,许多生物种及生态系统已经发生显著变化,未来这些变化还将继续。气候变化和人类活动的共同作用将对21世纪的陆地生态系统和内陆水系统产生重要影响,大部分陆地和淡水物种灭绝的风险都将增加,部分地区可能会发生不可逆转的变化。未来仅依靠生态系统自身的适应能力将不足以应对这些变化,需要辅以适应措施帮助生态系统适应气候变化。海岸带系统和低洼地区除了受气候变化的影响,还受到人类活动的强烈影响,并且影响的方式和结果因地而异。预计到2100年,全球平均海平面将上升0.28～0.98 m,相对海平面上升差异较大。到2100年,数以亿计的人将受到沿海洪水的影响。未来海岸带地区适应的相对成本会有很大的区域差异。在全球尺度上,采取防御措施取得的效益仍要高于不作为而付出的社会经济成本。发达国家比发展中国家具有更强的适应气候变化能力,可持续发展的气候恢复力也更大。     

The risk of sea level rise

The United Nations Framework Convention on Climate Change requires nations to implement measures for adapting to rising sea level and other effects of changing climate. To decide upon an appropriate response, coastal planners and engineers must weigh the cost of these measures against the likely cost of failing to prepare, which depends on the probability of the sea rising a particular amount.This study estimates such a probability distribution, using models employed by previous assessments, as well as the subjective assessments of twenty climate and glaciology reviewers about the values of particular model coefficients. The reviewer assumptions imply a 50 percent chance that the average global temperature will rise 2 °C, as well as a 5 percent chance that temperatures will rise 4.7 °C by 2100. The resulting impact of climate change on sea level has a 50 percent chance of exceeding 34 cm and a 1% chance of exceeding one meter by the year 2100, as well as a 3 percent chance of a 2 meter rise and a 1 percent chance of a 4 meter rise by the year 2200.The models and assumptions employed by this study suggest that greenhouse gases have contributed 0.5 mm/yr to sea level over the last century. Tidal gauges suggest that sea level is rising about 1.8 mm/yr worldwide, and 2.5–3.0 mm/yr along most of the U.S. Coast. It is reasonable to expect that sea level in most locations will continue to rise more rapidly than the contribution from climate change alone.We provide a set of normalized projections which express the extent to which climate change is likely to accelerate the rate of sea level rise. Those projections suggest that there is a 65 percent chance that sea level will rise 1 mm/yr more rapidly in the next 30 years than it has been rising in the last century. Assuming that nonclimatic factors do not change, there is a 50 percent chance that global sea level will rise 45 cm, and a 1 percent chance of a 112 cm rise by the year 2100; the corresponding estimates for New York City are 55 and 122 cm.Climate change impact assessments concerning agriculture, forests, water resources, and other noncoastal resources should also employ probability-based projections of regional climate change. Results from general circulation models usually provide neither the most likely scenario nor the full range of possible outcomes; probabilistic projections do convey this information. Moreover, probabilistic projections can make use of all the available knowledge, including the views of skeptics; the opinions of those who study ice cores, fossils, and other empirical evidence; and the insights of climate modelers, which may be as useful as the model results themselves.The U.S. Government right to retain a non-exclusive royalty-free license in and to any copyright is acknowledged.     

Cultural ecosystem services caught in a ‘coastal squeeze’ between sea level rise and urban expansion

Sea level rise and urbanization exert complex synergistic pressures on the provision of ecosystem services (ES) in coastal regions. Anticipating when and where both biophysical and cultural ES will be affected by these two types of coastal environmental change is critical for sustainable land-use planning and management. Biophysical (provisioning and regulating) services can be mapped using secondary data. We demonstrate an approach to mapping cultural ES by engaging stakeholders in iterative participatory mapping of personally and communally valuable cultural ES. We identify hotspots where highly valued cultural ES and high values for biophysical ES co-occur and generate spatially-explicit projections of sea level rise and urban expansion through 2060 to quantify impacts of the ‘coastal squeeze’ on ES. We study Johns Island, South Carolina, USA as an example of a vulnerable community in a low-lying region experiencing both rising water levels and a rapid influx of new residents and development. Our projections of environmental change through 2060 indicate that on Johns Island, cultural ES face disproportionately greater risk of decline than biophysical ES, with almost three quarters of the island’s cultural ES affected. We find that hotspots for cultural ES, such as community heritage sites and scenic vistas of oak-lined roads and marshes, rarely co-occur (only 3% area) with biophysical ES such as high values of carbon sequestration and agricultural production. This confirms the importance of engaging with local stakeholders to map cultural ES and puts them on a more level playing field with biophysical ES in decision-making contexts. Projected declines and limited overlap between biophysical and cultural ES highlight the need for tighter coordination between conservation and community planning, and for including locally valued cultural ES in assessments of threats posed by the ‘coastal squeeze’ of sea level rise and urban expansion.     

Simplified method for scenario-based risk assessment adaptation planning in the coastal zone

The development of successful coastal adaptation strategies for both the built and natural environments requires combining scenarios of climate change and socio-economic conditions, and risk assessment. Such planning needs to consider the adaptation costs and residual damages over time that may occur given a range of possible storm conditions for any given sea level rise scenario. Using the metric of the expected value of annual adaptation costs and residual damages, or another metric that can be related to the elevation of flooding, a simplified method to carry this out is presented. The approach relies upon developing damage-flooding depth probability exceedance curves for various scenarios over a given planning period and determining the areas under the curves. While the approach does have limitations, it is less complex to implement than using Monte Carlo simulation approaches and may be more intuitive to decision makers. A case study in Maine, USA is carried out to illustrate the method.     

Place-based or sector-based adaptation? A case study of municipal and fishery policy integration

Place-based adaptation planning is an approach to address cross-sectoral and multi-level governance concerns as well as to build local adaptive capacity in vulnerable resource-dependent communities facing the adverse impacts of climate change. In contrast, sector-based adaptation planning focuses on addressing climate change impacts on individual economic sectors (e.g. fisheries or forestry) or sub-sectors (such as lobsters or timber). Yet, linking sectoral approaches with local adaptation policies is challenging. More effort is needed to identify opportunities for complementary adaptation strategies and policy integration to foster multiple benefits. In this article, we use a case study of fishery sector resources and municipal adaptation planning in Nova Scotia to demonstrate how meaningful entry points could catalyse policy integration and lead to co-benefits across multiple levels and stakeholder groups. Drawing on a fisheries systems and fish chain framework, we identify and assess several entry points for policy integration across sector- and place-based adaptation domains within coastal habitats, as well as harvesting, processing, and marketing sectors. The analysis highlights the multiple benefits of integrating local municipal adaptation plans with multi-scale resource sectors especially towards monitoring ecosystem changes, protecting essential infrastructure, and securing local livelihoods.

POLICY RELEVANCE

Climate change is having a growing impact on coastal communities around the world, with consequences for sea-level rise, critical habitats, essential infrastructure, and multiple economic sectors and industries. This Canadian case study demonstrates how municipal adaptation initiatives can be complementary to sector-based adaptation at both local and regional levels through various entry points across commodity production chains. Policy integration across place-based and sector-based adaptation processes should lead to multiple benefits such as conserving marine biodiversity, protecting essential infrastructure, and securing livelihoods. Our analysis, which focuses specifically on the fishery sector and coastal communities, shows that these co-benefits may arise particularly in such coastal-marine systems and provide policy lessons to terrestrial systems and other sectors.     

Evaluation of hydrological effect of stakeholder prioritized climate change adaptation options based on multi-model regional climate projections

An integrated process involving participatory and modelling approaches for prioritizing and evaluating climate change adaptation options for the Kangsabati reservoir catchment is presented here. We assess the potential effects of climate change on water resources and evaluate the ability of stakeholder prioritized adaptation options to address adaptation requirements using the Water Evaluation And Planning (WEAP) model. Two adaptation options, check dams and increasing forest cover, are prioritized using pair-wise comparison and scenario analysis. Future streamflow projections are generated for the mid-21^st century period (2021–2050) using four high resolution (~25 km) Regional Climate Models and their ensemble mean for SRES A1B scenario. WEAP simulations indicate that, compared to a base scenario without adaptation, both adaptation options reduce streamflow. In comparison to check dams, increasing forest cover shows greater ability to address adaptation requirements as demonstrated by the temporal pattern and magnitude of streamflow reduction. Additionally, over the 30 year period, effectiveness of check dams in reducing streamflow decreases by up to 40 %, while that of forest cover increases by up to 47 %. Our study highlights the merits of a comparative assessment of adaptation options and we conclude that a combined approach involving stakeholders, scenario analysis, modelling techniques and multi-model projections may support climate change adaptation decision-making in the face of uncertainty.     

Modelling the combined impacts of sea-level rise and land subsidence on storm tides induced flooding of the Huangpu River in Shanghai, China

This paper presents a scenario-based study that investigates the interaction between sea-level rise and land subsidence on the storm tides induced fluvial flooding in the Huangpu river floodplain. Two projections of relative sea level rise (RSLR) were presented (2030 and 2050). Water level projections at the gauging stations for different return periods were generated using a simplified algebraic summation of the eustatic sea-level rise, land subsidence and storm tide level. Frequency analysis with relative sea level rise taken into account shows that land subsidence contributes to the majority of the RSLR (between 60 % and 70 %). Furthermore, a 1D/2D coupled flood inundation model (FloodMap) was used to predict the river flow and flood inundation, after calibration using the August 1997 flood event. Numerical simulation with projected RSLR suggests that, the combined impact of eustatic sea-level rise and land subsidence would be a significantly reduced flood return period for a given water level, thus effective degradation of the current flood defences. In the absence of adaptation measures, storm flooding will cause up to 40 % more inundation, particularly in the upstream of the river.     

A method to estimate climate-critical construction materials applied to seaport protection

Climate adaptation for coastal infrastructure projects raises unique challenges because global-scale environmental changes may require similar projects to be completed in many locations over the same time frame. Existing methods to forecast resource demand and capacity do not consider this phenomenon of a global change affecting many localities and the resulting increased demand for resources. Current methods do not relate to the most up-to-date climate science information, and they are too costly or too imprecise to generate global, regional, and local forecasts of “climate-critical resources” that will be required for infrastructure protection. They either require too much effort to create the many localized designs or are too coarse to consider information sources about local conditions and structure-specific engineering knowledge. We formalized the concept of a “minimum assumption credible design” (MACD) to leverage available local information (topography/bathymetry and existing infrastructure) and the essential engineering knowledge and required construction materials (i.e., a design cross-section template). The aggregation of the resources required for individual local structures then forecasts the resource demand for global adaptation projects. We illustrate the application of the MACD method to estimate the demand for construction materials critical to protect seaports from sea-level-rise-enhanced storm surges. We examined 221 of the world’s 3,300+ seaports to calculate the resource requirements for a coastal storm surge protection structure suited to current upper-bound projections of two meters of sea level rise by 2100. We found that a project of this scale would require approximately 436 million cubic meters of construction materials, including cement, sand, aggregate, steel rebar, and riprap. For cement alone, ∼49 million metric tons would be required. The deployment of the MACD method would make resource forecasts for adaptation projects more transparent and widely accessible and would highlight areas where current engineering knowledge or material, engineering workforce, and equipment capacity fall short of meeting the demands of adaptation projects.     

Simulations of Hurricane Katrina (2005) under sea level and climate conditions for 1900

Global warming may result in substantial sea level rise and more intense hurricanes over the next century, leading to more severe coastal flooding. Here, observed climate and sea level trends over the last century (c. 1900s to 2000s) are used to provide insight regarding future coastal inundation trends. The actual impacts of Hurricane Katrina (2005) in New Orleans are compared with the impacts of a similar hypothetical hurricane occurring c. 1900. Estimated regional sea level rise since 1900 of 0.75 m, which contains a dominant land subsidence contribution (0.57 m), serves as a ‘prototype’ for future climate-change induced sea level rise in other regions. Landform conditions c. 1900 were estimated by changing frictional resistance based on expected additional wetlands at lower sea levels. Surge simulations suggest that flood elevations would have been 15 to 60 % lower c. 1900 than the conditions observed in 2005. This drastic change suggests that significantly more flood damage occurred in 2005 than would have occurred if sea level and climate conditions had been like those c. 1900. We further show that, in New Orleans, sea level rise dominates surge-induced flooding changes, not only by increasing mean sea level, but also by leading to decreased wetland area. Together, these effects enable larger surges. Projecting forward, future global sea level changes of the magnitude examined here are expected to lead to increased flooding in coastal regions, even if the storm climate is unchanged. Such flooding increases in densely populated areas would presumably lead to more widespread destruction.     

Implications of sea-level rise and extreme events around Europe: a review of coastal energy infrastructure

Sea-level rise and extreme events have the potential to significantly impact coastal energy infrastructure through flooding and erosion. Disruptions to supply, transportation and storage of energy have global ramifications and potential contamination of the natural environment. On a European scale, there is limited information about energy facilities and their strategic plans for adapting to climate change. Using a Geographical Information System this paper assesses coastal energy infrastructure, comprising (1) oil/gas/LNG/tanker terminals and (2) nuclear power stations. It discusses planning and adaptation for sea-level rise and extreme events. Results indicate 158 major oil/gas/LNG/tanker terminals in the European coastal zone, with 40 % located on the North Sea coast. There are 71 operating nuclear reactors on the coast (37 % of the total of European coastal countries), with further locations planned in the Black, Mediterranean and Baltic Seas. The UK has three times more coastal energy facilities than any other country. Many north-west European countries who have a high reliance on coastal energy infrastructure have a high awareness of sea-level rise and plan for future change. With long design lives of energy facilities, anticipating short, medium and long-term environmental and climatic change is crucial in the design, future monitoring and maintenance of facilities. Adaptation of coastal infrastructure is of international importance, so will be an ongoing important issue throughout the 21^st century.     

城市气象研究国际前沿动态综述

通过梳理2018年8月在美国纽约举行的第十届城市气候国际会议主要研究成果,分类汇总了城市气象研究的最新国际进展与发展趋势,包括城市气候过程、城市环境下气候变化适应与应对、气候条件下城市规划和管理、最新城市气象探测技术、城市环境数值模拟、大城市气候、城市遥感、城市地区极端天气等方面。在此基础上,根据我国城市化发展特性,探讨了我国城市气象研究的未来发展方向。     

Characterizing climate change risks by linking robust decision frameworks and uncertain probabilistic projections

There is increasing concern that avoiding climate change impacts will require proactive adaptation, particularly for infrastructure systems with long lifespans. However, one challenge in adaptation is the uncertainty surrounding climate change projections generated by general circulation models (GCMs). This uncertainty has been addressed in different ways. For example, some researchers use ensembles of GCMs to generate probabilistic climate change projections, but these projections can be highly sensitive to assumptions about model independence and weighting schemes. Because of these issues, others argue that robustness-based approaches to climate adaptation are more appropriate, since they do not rely on a precise probabilistic representation of uncertainty. In this research, we present a new approach for characterizing climate change risks that leverages robust decision frameworks and probabilistic GCM ensembles. The scenario discovery process is used to search across a multi-dimensional space and identify climate scenarios most associated with system failure, and a Bayesian statistical model informed by GCM projections is then developed to estimate the probability of those scenarios. This provides an important advancement in that it can incorporate decision-relevant climate variables beyond mean temperature and precipitation and account for uncertainty in probabilistic estimates in a straightforward way. We also suggest several advancements building on prior approaches to Bayesian modeling of climate change projections to make them more broadly applicable. We demonstrate the methodology using proposed water resources infrastructure in Lake Tana, Ethiopia, where GCM disagreement on changes in future rainfall presents a major challenge for infrastructure planning.