Global sea levels have risen through the 20th century. These rises will almost certainly accelerate through the 21st century and beyond because of global warming, but their magnitude remains uncertain. Key uncertainties include the possible role of the Greenland and West Antarctic ice sheets and the amplitude of regional changes in sea level. In many areas, nonclimatic components of relative sea-level change (mainly subsidence) can also be locally appreciable. Although the impacts of sea-level rise are potentially large, the application and success of adaptation are large uncertainties that require more assessment and consideration.

http://science.sciencemag.org/content/sci/328/5985/1517.full.pdf

Sea-Level Rise and Its Impact on Coastal Zones

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 from baseline 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.

/pdf/future-coastal-population-growth-and-exposure-to-sea-level-4ncamqes3x.pdf

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

Anthropogenic global warming has significantly influenced physical and biological processes at global and regional scales. The observed and anticipated changes in global climate present significant opportunities and challenges for societies and economies. We compare the vulnerability of 132 national economies to potential climate change impacts on their capture fisheries using an indicator-based approach. Countries in Central and Western Africa (e.g. Malawi, Guinea, Senegal, and Uganda), Peru and Colombia in north-western South America, and four tropical Asian countries (Bangladesh, Cambodia, Pakistan, and Yemen) were identified as most vulnerable. This vulnerability was due to the combined effect of predicted warming, the relative importance of fisheries to national economies and diets, and limited societal capacity to adapt to potential impacts and opportunities. Many vulnerable countries were also among the world’s least developed countries whose inhabitants are among the world’s poorest and twice as reliant on fish, which provides 27% of dietary protein compared to 13% in less vulnerable countries. These countries also produce 20% of the world’s fish exports and are in greatest need of adaptation planning to maintain or enhance the contribution that fisheries can make to poverty reduction. Although the precise impacts and direction of climate-driven change for particular fish stocks and fisheries are uncertain, our analysis suggests they are likely to lead to either increased economic hardship or missed opportunities for development in countries that depend upon fisheries but lack the capacity to adapt.

/pdf/vulnerability-of-national-economies-to-the-impacts-of-1dogy4xth3.pdf

Vulnerability of national economies to the impacts of climate change on fisheries

To develop improved estimates of (1) #ooding due to storm surges, and (2) wetland losses due to accelerated sea-level rise, the work of Hoozemans et al. (1993) is extended to a dynamic analysis. It considers the e!ects of several simultaneously changing factors, including: (1) global sea-level rise and subsidence; (2) increasing coastal population; and (3) improving standards of #ood defence (using GNP/capita as an ‘ability-to-paya parameter). The global sea-level rise scenarios are derived from two General Circulation Model (GCM) experiments of the Hadley Centre: (1) the HadCM2 greenhouse gas only ensemble experiment and (2) the more recent HadCM3 greenhouse gas only experiment. In all cases there is a global rise in sea level of about 38 cm from 1990 to the 2080s. No other climate change is considered. Relative to an evolving reference scenario without sea-level rise, this analysis suggests that the number of people #ooded by storm surge in a typical year will be more than "ve times higher due to sea-level rise by the 2080s. Many of these people will experience annual or more frequent #ooding, suggesting that the increase in #ood frequency will be more than nuisance level and some response (increased protection, migration, etc.) will be required. In absolute terms, the areas most vulnerable to #ooding are the southern Mediterranean, Africa, and most particularly, South and South-east Asia where there is a concentration of low-lying populated deltas. However, the Caribbean, the Indian Ocean islands and the Paci"c Ocean small islands may experience the largest relative increase in #ood risk. By the 2080s, sea-level rise could cause the loss of up to 22% of the world’s coastal wetlands. When combined with other losses due to direct human action, up to 70% of the world’s coastal wetlands could be lost by the 2080s, although there is considerable uncertainty. Therefore, sea-level rise would reinforce other adverse trends of wetland loss. The largest losses due to sea-level rise will be around the Mediterranean and Baltic and to a lesser extent on the Atlantic coast of Central and North America and the smaller islands of the Caribbean. Collectively, these results show that a relatively small global rise in sea level could have signi"cant adverse impacts if there is no adaptive response. Given the ‘commitment to sea-level risea irrespective of any realistic future emissions policy, there is a need to start strategic planning of appropriate responses now. Given that coastal #ooding and wetland loss are already important problems, such planning could have immediate bene"ts. ( 1999 Elsevier Science Ltd. All rights reserved.

/pdf/increasing-flood-risk-and-wetland-losses-due-to-global-sea-22e7a3uqhm.pdf

Increasing flood risk and wetland losses due to global sea-level rise: regional and global analyses

In 2000, almost 700 million international tourist arrivals were counted worldwide. Even though a global activity of this scale can be assumed to have a substantial impact on the environment, its consequences have never been assessed and quantified. In this contribution, five major aspects of the leisure-related alteration of the environment are investigated: (1) the change of land cover and land use, (2) the use of energy and its associated impacts, (3) the exchange of biota over geographical barriers and the extinction of wild species, (4) the exchange and dispersion of diseases, and (5), a psychological consequence of travel, the changes in the perception and the understanding of the environment initiated by travel.

http://ssu.ac.ir/cms/fileadmin/user_upload/Moavenatha/MBehdashti/Pishgiri_Bimariha/00malt2/27.pdf

Global environmental consequences of tourism

Coastal vulnerability assessments still focus mainly on sea-level rise, with less attention paid to other dimensions of climate change. The influence of non-climatic environmental change or socio-economic change is even less considered, and is often completely ignored. Given that the profound coastal changes of the twentieth century are likely to continue through the twenty-first century, this is a major omission, which may overstate the importance of climate change, and may also miss significant interactions of climate change with other non-climate drivers. To better support climate and coastal management policy development, more integrated assessments of climatic change in coastal areas are required, including the significant non-climatic changes. This paper explores the development of relevant climate and non-climate drivers, with an emphasis on the non-climate drivers. While these issues are applicable within any scenario framework, our ideas are illustrated using the widely used SRES scenarios, with both impacts and adaptation being considered. Importantly, scenario development is a process, and the assumptions that are made about future conditions concerning the coast need to be explicit, transparent and open to scientific debate concerning their realism and likelihood. These issues are generic across other sectors.

Climate change and coastal vulnerability assessment: scenarios for integrated assessment

Small island states

Coastal tourism development in Southeast Asia : relevance and lessons for coastal zone management

Dachangshan Dao represents one of China's latest moves to develop tourism in the coastal zone. This paper examines how homestay operators on Dachangshan Dao perceive the tourism impact on their community and how their social demographics influence their perception towards tourism. Using factor analysis the impacts on the local community perceived by the homestay operator were condensed into seven factors: economic impacts, the interaction between tourism and other sectors, life quality improvement, general physical environment deterioration, beach degradation, sea water pollution, and interruption to quiet life. Concurrently, all respondents were segmented into four groups according to social demographics (gender, age, education level and occupation) by cluster analysis and the relationship between seven factors concerning tourism's impacts and those four cluster groups with different social demographics were established.

P.P. Wong

Papers

Climate change and coastal vulnerability assessment: scenarios for integrated assessment

Small island states

Coastal tourism development in Southeast Asia : relevance and lessons for coastal zone management

Residents' Perception of Tourism Impacts: A Case Study of Homestay Operators in Dachangshan Dao, North-East China

Recovery from a large tsunami mapped over time: the Aceh coast, Sumatra.