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.     

Environmental non-migration as adaptation in hazard-prone areas: Evidence from coastal Bangladesh

Despite suffering significantly from the adverse impacts of climate change and human-induced hazards, many people at risk deliberately choose not to migrate from hazard-prone areas in coastal Bangladesh. As many of them encounter significant challenges in maintaining their livelihoods, ascertaining how and under what circumstances voluntary non-migration decisions occur is crucial. Only a handful of studies have investigated whether individuals and groups who decide to stay put in the face of climatic hazards consider their decision to be an adaptive action. In this regard, this study contributes to the existing literature by empirically investigating the voluntary non-migration decision as an adaptation strategy through an exploration of the factors affecting this decision. We employed a systematic random sampling technique and selected 627 respondents from two climatic hazard-prone coastal districts: Khulna and Satkhira. Using the Generalized Structural Equation Model (GSEM), we found that voluntary non-migrants (84% of total respondents) appeared to enjoy the significant advantage of access to their communities' basic need provision and social support. Furthermore, the social, psychological, and economic opportunities found at their existing location (e.g., better income prospects, affordable living costs, receipt of financial help during post-disaster periods, and skills allowing them to stay in that location), as well as their access to local natural resources, strengthened their social capital and thus influenced their desire to stay. Together, these factors enhanced people’s adaptability to climatic shocks and motivated them to choose voluntary non-migration as an adaptation option.     

Global assessment of the effectiveness of adaptation in coastal areas based on RCP/SSP scenarios

Climatic Change - The objective of this study is to assess the global impact of sea level rise and to evaluate the effectiveness of adaptation. Global areas of inundation due to sea level rise are...     

Uncertainty in an emissions-constrained world

Our study focuses on uncertainty in greenhouse gas (GHG) emissions from anthropogenic sources, including land use and land-use change activities. We aim to understand the relevance of diagnostic (retrospective) and prognostic (prospective) uncertainty in an emissions-temperature setting that seeks to constrain global warming and to link uncertainty consistently across temporal scales. We discuss diagnostic and prognostic uncertainty in a systems setting that allows any country to understand its national and near-term mitigation and adaptation efforts in a globally consistent and long-term context. Cumulative emissions are not only constrained and globally binding but exhibit quantitative uncertainty; and whether or not compliance with an agreed temperature target will be achieved is also uncertain. To facilitate discussions, we focus on two countries, the USA and China. While our study addresses whether or not future increase in global temperature can be kept below 2, 3, or 4 °C targets, its primary aim is to use those targets to demonstrate the relevance of both diagnostic and prognostic uncertainty. We show how to combine diagnostic and prognostic uncertainty to take more educated (precautionary) decisions for reducing emissions toward an agreed temperature target; and how to perceive combined diagnostic and prognostic uncertainty-related risk. Diagnostic uncertainty is the uncertainty contained in inventoried emission estimates and relates to the risk that true GHG emissions are greater than inventoried emission estimates reported in a specified year; prognostic uncertainty refers to cumulative emissions between a start year and a future target year, and relates to the risk that an agreed temperature target is exceeded.     

Safe policies in an uncertain climate: an application of FUND

Various aspects of the role of uncertainty in greenhouse gas emission reduction policy are analyzed with the integrated assessment model FUND. FUND couples simple models of economy, climate, climate impacts, and emission abatement. Probability distribution functions are assumed for all major parameters in the model. Monte Carlo analyses are used to study the effects of parametric uncertainties. Uncertainties are found to be large and grow over time. Uncertainties about climate change impacts are more serious than uncertainties about emission reduction costs, so that welfare-maximizing policies are stricter under uncertainty than under certainty. This is more pronounced without than with international cooperation. Whether or not countries cooperate with one another is more important than whether or not uncertainty is considered. Meeting exogenously defined emission targets may be more or less difficult under uncertainty than under certainty, depending on the asymmetry in the uncertainty and the central estimate of interest. The major uncertainty in meeting emissions targets in each of a range of possible future is the timing of starting (serious) reduction policies. In a scenario aiming at a stable CO₂ concentration of 550 ppm, the start date varies 20 years for Annex I countries, and much longer for non-Annex countries. Atmospheric stabilization at 550 ppm does not avoid serious risks with regard to climate change impacts. At the long term, it is possible to avoid such risks but only through very strict emission control at high economic costs.     

Climate change and coastal flooding in Metro Boston: impacts and adaptation strategies

Sea level rise (SLR) due to climate change will increase storm surge height along the 825 km long coastline of Metro Boston, USA. Land at risk consists of urban waterfront with piers and armoring, residential areas with and without seawalls and revetments, and undeveloped land with either rock coasts or gently sloping beachfront and low-lying coastal marshes. Risk-based analysis shows that the cumulative 100 year economic impacts on developed areas from increased storm surge flooding depend heavily upon the adaptation response, location, and estimated sea level rise. Generally it is found that it is advantageous to use expensive structural protection in areas that are highly developed and less structural approaches such as floodproofing and limiting or removing development in less developed or environmentally sensitive areas.     

AD-DICE: an implementation of adaptation in the DICE model

Integrated Assessment Models (IAMS) have helped us over the past decade to understand the interactions between the environment and the economy in the context of climate change. Although it has also long been recognized that adaptation is a powerful and necessary tool to combat the adverse effects of climate change, most IAMS have not explicitly included the option of adaptation in combating climate change. This paper adds to the IAM and climate change literature by explicitly including adaptation in an IAM, thereby making the trade-offs between adaptation and mitigation visible. Specifically, a theoretical framework is created and used to implement adaptation as a decision variable into the DICE model. We use our new AD-DICE model to derive the adaptation cost functions implicit in the DICE model. In our set-up, adaptation and mitigation decisions are separable and AD-DICE can mimic DICE when adaptation is optimal. We find that our specification of the adaptation costs is robust with respect to the mitigation policy scenarios and parameter values. Our numerical results show that adaptation is a powerful option to combat climate change, as it reduces most of the potential costs of climate change in earlier periods, while mitigation does so in later periods.     

Rethinking barriers to adaptation: Mechanism-based explanation of impasses in the governance of an innovative adaptation measure

Many of the possible barriers in the governance of climate change adaptation have already been identified and catalogued in the academic literature. Thus far it has proven to be difficult to provide meaningful recommendations on how to deal with these barriers. In this paper we propose a different perspective, with different epistemological assumptions about cause and effect than most existing barrier studies, to analyze why adaptation is often challenging. Using the mechanismic framework, we study how the idea for an innovative “Water Plaza” was realized in the city of Rotterdam, the Netherlands. Mechanisms are understood as patterns of interaction between actors that bring about change in the governance process that lead to policy impasses. Our analysis reveals three mechanisms that explain the impasses in the first Water Plaza pilot project: the risk-innovation mechanism, the frame polarization mechanism, and the conflict infection mechanism. Only after several substantive changes in the project design, location choice, and process architecture was the project of Water Plaza's revitalized. We discuss how the short-sighted ideas about cause–effect relationships, reflected in the superficial identification of barriers, may prove to be counterproductive; if there is high uncertainty about the risks of an innovation, the solution of offering more certainty is not very helpful and could, as it happened in the case study, trigger other mechanisms, creating an even tighter deadlock. Our study also suggests that when adaptation is considered as something innovative, the chances will increase that the risk-innovation mechanism will occur. We conclude that unearthing mechanisms offers new opportunities and different types of strategic interventions in practice than most existing studies have offered.     

Regional assessment of climate change impacts on coastal and fluvial ecosystems and the scope for adaptation

Ecosystem changes in floodplains could be a major issue during the twenty-first century as designated habitat areas are affected by climate change and floodplain management options. As part of the RegIS project, a Regional Impact Simulator has been developed to investigate these potential changes. This paper presents the methodologies and results of biodiversity metamodels used within the Regional Impact Simulator for two regions of the UK: East Anglia and North West England. Potential impacts and adaptations to future climate and socio-economic scenarios are analysed for three habitat types in floodplains (saltmarsh, coastal grazing marsh and fluvial grazing marsh) and selected species. An important finding is that management choices, which can be linked to socio-economic futures have a greater potential impact on habitat viability than climate change. The choices society makes will therefore be key to protection and conservation of biodiversity. The analyses also show that coastal grazing marsh is the most vulnerable habitat to sea-level rise, although there is a scope for substituting losses with fluvial grazing marsh. These results indicate that these methods provide a useful approach for assessing potential biodiversity changes at the regional scale, including the effect of different policies.     

On the role of climate scenarios for adaptation planning

Climate scenarios have been widely used in impact, vulnerability and adaptation assessments of climate change. However, few studies have actually looked at the role played by climate scenarios in adaptation planning. This paper examines how climate scenarios fit in three broad adaptation frameworks: the IPCC approach, risk approaches, and human development approaches. The use (or not) of climate scenarios in three real projects, corresponding to each adaptation approach, is investigated. It is shown that the role played by climate scenarios is dependant on the adaptation assessment approach, availability of technical and financial capacity to handle scenario information, and the type of adaptation being considered.     

Corruption in cyclone preparedness and relief efforts in coastal Bangladesh: Lessons for climate adaptation?

This article seeks to draw possible lessons for adaptation programmes in Bangladesh by examining whether cyclone preparedness and relief interventions are subject to corrupt practices. Based on a random sample survey of 278 households, three focus-group discussions and seven key-informant interviews, the article investigates the nature and extent of corruption in pre- and post-disaster interventions in Khulna before and after Cyclone Aila in May 2009. Ninety nine percent of households reported losses from corrupt practices. Post-disaster interventions (such as food aid and public works schemes) suffered from greater levels, and worse types, of corruption than pre-disaster interventions (such as cyclone warning systems and disaster-preparedness training). Using an asset index created using principal component analysis, the article assesses how corruption affected wealth quartiles. Ultra-poor households were affected more by corruption in pre-disaster interventions, the wealthiest quartile more in certain post-disaster interventions, in particular public works and non-governmental interventions. These findings may hold lessons for attempts to increase resilience as current adaptation measures mirror some cyclone preparedness and relief efforts.     

On coastal flow in the northeast gulf of Alaska near yakutat 1

Abstract

Seasonal maps of geopotential topography and salinity at 10 m were prepared for a region in the northeast Gulf of Alaska near Yakutat. Coastal waters in this region receive considerable runoff in late summer, but the dilution does not result in a greatly intensified coastal flow. Baroclinic coastal flow in the northeast Gulf appears to be weaker than the coastal flow (Kenai Current) to the west along the Kenai Peninsula and in Shelikof Strait.     

On the role of criticality in coastal flows over irregular bottom topography

A simple expansion technique is developed for predicting the response of a horizontally sheared oceanic coastal flow over uniform coastal topography to variations in that bottom topography. The technique is illustrated by application to supercritical and subcritical flows. The response of the supercritical flow is local, while that of the subcritical flow extends downstream to be eventually attenuated by frictional damping. However, the response of both flow types is weak unless the flow is nearly critical.     

当代大气科学的几个重大研究课题

自70年代末特别是80年代以来,随着全球大气研究计划(GARP)的完成,大气科学研究的重点以及国际合作计划基本上已集中到几个新的重大领域,它们是:气候变化及异常,灾害性天气的临近预报。大气化学监测及研究,地球流体力学,另外还有中层大气研究。这几个重大科学领域中的前三项,直接同国民经济有关,而第四项的研究则为前三项中的问题提供理论基础,并开拓新的探索。因此,上述新领域的研究结果,既可以解决人类社会发展提出的迫切问题,为国民经济和人民生活服务,也必将带动整个大气科学的发展,把大气科学水平推向一个新的高度。     

The economic value of delaying adaptation to sea-level rise: An application to coastal properties in Connecticut

The magnitude and frequency of coastal storms are expected to increase with rising global sea levels, which necessitates evaluating coastal flood adaptation measures. This study examines an important issue in the context of coastal flood protection, namely, the decision when to adopt protection measures. For any given coastal region, our benefit-cost framework allows us to determine the optimal timing of initiating protection that maximizes expected net benefits. We present an application of this framework to a coastal area in Connecticut. Our results suggest that the optimal timing of adopting protection may vary across different census blocks within the study area. We find that using a relatively low discount rate in the benefit-cost analysis implies greater heterogeneity in the timing decisions and earlier overall adoption, whereas, with higher discount rates, the timing decisions are reduced to a choice between early protection and no protection at all. If possible negative environmental and aesthetic impacts of sea barriers are taken into account, delaying protection would become more desirable, with the extent of delay being sensitive to the relative magnitude of one-time costs (e.g., loss of ocean view and recreational opportunities) vs. continuous costs (e.g., shoreline erosion and loss of wetlands).