SEA LEVEL RISE AND EQUITY WEIGHTING

Using the FUND model, an impact assessment is conducted over the 21st century for rises in sea level of up to 2-m/century and a range of national socio-economic scenarios. This model balances the costs of retreat with the costs of protection, including the effects of coastal squeeze. While the costs of sea-level rise increase due to greater damage and protection costs, the model suggests that an optimum response in a benefit-cost sense remains widespread protection of developed coastal areas, as identified in earlier analyses. The socio-economic scenarios are also important in terms of influencing these costs. In terms of the four components of costs considered in FUND, protection seems to dominate, with substantial costs from wetland loss under some scenarios. The regional distribution of costs shows that a few regions experience most of the costs, especially East Asia, North America, Europe and South Asia. Importantly, this analysis suggests that protection is much more likely and rational than is widely assumed, even with a large rise in sea level. However, there are some important limitations to the analysis, which collectively suggest that protection may not be as widespread as suggested in the FUND analysis. Equity weighting allows the damages to be modified to reflect the wealth of those impacted by sea-level rise. Taking these distributional issues into account increases damage estimates by a factor of three, reflecting that the coasts fall disproportionately on poorer developing countries.climate change, sea level rise, equity weighting

GLOBAL ESTIMATES OF THE IMPACT OF A COLLAPSE OF THE WEST ANTARCTIC ICE SHEET: AN APPLICATION OF FUND

The threat of an abrupt and extreme rise in sea level is widely discussed in the media, but little understood in practise, including the likely impacts of such a rise. This paper explores for the first time the global impacts of extreme sea-level rise, triggered by a hypothetical collapse of the West Antarctic Ice Sheet (WAIS). As the potential contributions remain uncertain, a wide range of scenarios are explored: WAIS contributions to sea-level rise of between 0.5m/century up to 5m/century. Together with other business-as-usual sea-level contributions, in the worst case this gives an approximately 6-m rise of global-mean sea level from 2030 to 2130. Global exposure to extreme sea-level rise is significant: roughly 400 million people (or about 8% of global population) are threatened by a 5-m rise in sea level, just based on 1995 data. The coastal module within the FUND model is tuned with global data on coastal zone characteristics concerning population, land areas and land use, and then used for impact analysis under the extreme sea-level rise scenarios. The model considers the interaction of (dry)land loss, wetland loss, protection costs and human displacement, assuming perfect adaptation based on cost-benefit analysis. Unlike earlier analyses, response costs are represented in a non-linear manner, including a sensitivity analysis based on response costs. It is found that much of the world’s coast would be abandoned given these extreme scenarios, although according to the global model, significant lengths of the world’s coast are worth defending even in the most extreme case. Hence, this suggests that actual population displacement would be a small fraction of the potential population displacement. This result is consistent with the present distribution of coastal population, which is heavily concentrated in specific areas. Hence a partial defence can protect most of the world’s coastal population. However, protection costs rise substantially diverting large amounts of investment from other sectors, and large areas of (dry)land and coastal wetlands are still predicted to be lost. While some observations of response to abrupt relative sea-level rise due to subsidence support the global model results, detailed case studies of the WAIS collapse in the Netherlands, Thames Estuary and the Rhone delta suggest a greater potential for abandonment than shown by the global model. This probably reflects a range of issues, including: (1) economic criteria such as the cost-benefit ratio is not the only factor which drives response decisions, with wider perceptions of risk driving the actual response; (2) the inefficiencies of adaptation in the real world, including indecision and competition for limited resources; and (3) the possible loss of confidence under the scenario of abrupt climate change. Collectively, these results illustrate an area where there are potential limits to adaptation, even when economic analysis suggests that adaptation will occur. The significant impacts found in the global model together with the potential for greater impacts as found in the detailed case studies shows that the response to abrupt sea-level rise is worthy of further research, including exploring the differing impact results by scale.Abrupt climate change, sea-level rise, coastal impacts, adaptation, adaptation limits

Impacts of climate change in coastal systems in Europe. PESETA-Coastal Systems study

Results of the physical impacts and adaptation cost assessment of sea-level rise for the European Union are presented for the A2 and B2 SRES socio-economic storylines and for a range of plausible sea-level rise scenarios, using data from the ECHAM4 and HADCM3 Global Climate Models (GCMs) models. In addition, to better understand the sensitivity of the results to the magnitude of sea-level rise, the full IPCC (2001) range of sea level rise predictions and scenarios of no climate change have also been modelled. These results are all derived using the global Dynamic Interactive Vulnerability Assessment (DIVA) tool for assessing regional to global coastal impacts and adaptation. Both the physical and economic impacts of sea-level rise increase with time for both the A2 and B2 storylines, especially under scenarios of high sea-level rise. Without adaptation, significant impacts and therefore damages are apparent. Significant populations are threatened with displacement by flooding and coastal erosion. An exploratory adaptation analysis using standard protection measures of dike construction and beach nourishment, where benefit-cost analysis suggests this is the optimum response, reduces these impacts significantly. While adaptation in Europe is likely to be much more diverse than these two smple options, these results demonstrate the significant benefits of protection, and more generally suggest that widespread adaptation to sustain human coastal activities would be prudent. Moreover, under these protection assumptions, coastal ecosystems are significantly reduced in area, especially under the high sea-level rise scenario and climate change raises significant challenges for wider coastal management in Europe, even if human uses in the coastal zone are protected.JRC.DG.J.2-The economics of climate change, energy and transpor

The Economic Impact of Substantial Sea-Level Rise

Using the FUND model, an impact assessment is conducted over the 21st century for rises in sea level of up to 2-m/century and a range of socio-economic scenarios downscaled to the national level, including the four SRES storylines. This model balances the costs of retreat with the costs of protection, including the effects of coastal squeeze. While the costs of sea-level rise increase with greater rise due to greater damage and protection costs, the model suggests that an optimum response in a benefit-cost sense remains widespread protection of developed coastal areas, as identified in earlier analyses. The socio-economic scenarios are also important in terms of influencing these costs. In terms of the four components of costs considered in FUND, protection dominates, with substantial costs from wetland loss under some scenarios. The regional distribution of costs shows that a few regions experience most of the costs, especially East Asia, North America, Europe and South Asia. Importantly, this analysis suggests that protection is much more likely and rational than is widely assumed, even with a large rise in sea level. This is underpinned by the strong economic growth in all the SRES scenarios: without this growth, the benefits of protection are significantly reduced. It should also be noted that some important limitations to the analysis are discussed, which collectively suggest that protection may not be as widespread as suggested in the FUND results. Equity weighting allows the damages to be modified to reflect the wealth of those impacted by sea-level rise. Taking these distributional issues into account increases damage estimates by a factor of three, reflecting that the costs of sea-level rise fall disproportionately on poorer developing countries.Sea-level rise;Socio-economic scenarios;costs;protection;equity weighting

Impacts of sea-level rise-induced erosion on the Catalan coast

The final publication is available at Springer via http://dx.doi.org/10.1007/s10113-016-1052-xThe Catalan coast as most of the developed Mediterranean coastal zone is characterized by the coincidence of stresses and pressures on the natural system with a high exposure and low adaptive capacity. Due to this, climate change-induced effects will increase natural hazards and aggravate their associated impacts and, in consequence, it is necessary to assess their effects for proper long-term management. In this work, we assess the impact of sea-level rise (SLR)-induced shoreline retreat on the Catalan coast for three scenarios ranging from 0.53 to 1.75 m by the year 2100. Implications are analysed in terms of affectation of two main functions provided by beaches, i.e. recreation and protection. Obtained results show that CC will be a serious threat to analysed functions since the expected enhanced shoreline retreat will severely decrease the recreational carrying capacity and the capacity of protection in the near future under tested scenarios. The actual level of development along the coastal zone reduces the natural resilient capacity of beaches to SLR in such a way that the lack of accommodation space can be identified as a main factor for the estimated impacts.Peer ReviewedPostprint (author's final draft

Ionospheric ion temperature forecasting in multiples of 27 days

he ionospheric variability found at auroral locations is usually assumed to be unpredictable. The magnetosphere, which drives this ionospheric variability via storms and substorms, is at best only qualitatively describable. In this study we demonstrate that over a 3 year period, ionospheric variability observed from Poker Flat, Alaska, has, in fact, a high degree of long-term predictability. The observations used in this study are (a) the solar wind high speed stream velocity measured by the NASA Advanced Composition Explorer satellite, used to define the corotating interaction region (CIR), and (b) the ion temperature at 300 km altitude measured by the National Science Foundation Poker Flat Incoherent Scatter Radar over Poker Flat, Alaska. After determining a seasonal and diurnal climatology for the ion temperature, we show that the residual ion temperature heating events occur synchronously with CIR-geospace interactions. Furthermore, we demonstrate examples of ion temperature forecasting at 27, 54, and 81 days. A rudimentary operational forecasting scenario is described for forecasting recurrence 27 days ahead for the CIR-generated geomagnetic storms. These forecasts apply specifically to satellite tracking operations (thermospheric drag) and emergency HF-radio communications (ionospheric modifications) in the polar regions. The forecast is based on present-day solar and solar wind observations that can be used to uniquely identify the coronal hole and its CIR. From this CIR epoch, a 27 day forecast is then made

A review of potential physical impacts on harbours in the Mediterranean Sea under climate change

The final publication is available at Springer via http://dx.doi.org/10.1007/s10113-016-0972-9The potential impact of climate change on port operations and infrastructures has received much less attention than the corresponding impact for beach systems. However, ports have always been vulnerable to weather extremes and climate change could enhance such occurrences at timescales comparable to the design lifetime of harbour engineering structures. The analysis in this paper starts with the main climatic variables affecting harbour engineering and exploitation. It continues with a review of the available projections for such variables first at global scale and then at a regional scale (Catalan coast in the western Mediterranean) as a study case for similar environments in the planet. The detailed assessment of impacts starts from downscaled projections for mean sea level and wave storms (wind not considered in the paper). This is followed by an analysis of the port operations and infrastructure performance that are relevant from a climate perspective. The key climatic factors here considered are relative sea level, wave storm features (height, period, direction and duration) and their combined effect, which is expected to produce the highest impacts. The paper ends with a discussion and some examples of analyses aiming at port adaptation to future climate change.Peer ReviewedPostprint (author's final draft

Future coastal population growth and exposure to sea-level rise and coastal flooding - A global assessment

Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting frombaseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise.We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential. Furthermore, we identify needs for further research and scope for improvement in this kind of scenario-based exposure analysis