Barbara Neumann

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 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.

Sea-level rise impacts and responses: a global perspective

Coastal hazards have long been present and are evolving due to a variety of different drivers: the long-term threat of climate change, including sea-level rise, adds a new dimension to these problems which is explored here. Globally, sea levels could rise in excess of 1 m this century, but the local rate of relative sea-level rise could be much greater than this because of subsidence or other factors which lower the land surface. This is important as the population of these subsiding areas is significant. Relative sea-level rise will result in inundation, flooding, erosion, wetland loss, saltwater intrusion and impeded drainage. This chapter has investigated the impacts of sea-level rise at a global scale on: (1) Sandy environments; (2) Wetlands and low-lying coasts; (3) Built environments; and (4) Energy and transport systems. Results indicate that without appropriate adaptation, environments could be significantly impacted, and those remote or financially less well off could become increasingly vulnerable. Further research and action is required into integrated impact assessments (including non-climatic drivers of change) to help those at risk and develop appropriate adaptation polices over short, medium and long timescales.

Making SDGs work for climate change hotspots

The impacts of climate change on peoples livelihoods have been widely documented. It is expected that climate and environmental change will hamper poverty reduction, or even exacerbate poverty in some or all of its dimensions. Changes in the biophysical environment, such as droughts, flooding, water quantity and quality, and degrading ecosystems, are expected to affect opportunities for people to generate income. These changes, combined with a deficiency in coping strategies and innovation to adapt to particular climate change threats, are in turn likely to lead to increased economic and social vulnerability of households and communities, especially amongst the poorest.

Strong sustainability in coastal areas: a conceptual interpretation of SDG 14

Humans derive many tangible and intangible benefits from coastal areas, providing essential components for social and economic development especially of less developed coastal states and island states. At the same time, growing human and environmental pressures in coastal areas have significant impacts on coastal systems, requiring urgent attention in many coastal areas globally. Sustainable development goal (SDG) 14 of the 2030 Agenda for Sustainable Development (henceforth the 2030 Agenda) aims for conservation and sustainable use of the oceans, seas, and marine resources, explicitly considering coastal areas in two of its targets (14.2 and 14.5). These promote, as we argue in this article, a strong sustainability concept by addressing protection, conservation, and management of coastal ecosystems and resources. The 2030 Agenda adopts the so-called “three-pillar-model” but does not specify how to balance the economic, social, and environmental dimensions in cases of trade-offs or conflicts. By analysing SDG 14 for the underlying sustainability concept, we derive decisive arguments for a strong sustainability concept and for the integration of constraint functions to avoid depletion of natural capital of coastal areas beyond safe minimum standards. In potential negotiations, targets 14.2 and 14.5 ought to serve as constraints to such depletion. However, such a rule-based framework has challenges and pitfalls which need to be addressed in the implementation and policy process. We discuss these for coastal areas in the context of SDG 14 and provide recommendations for coastal governance and for the process ahead.

Accelerating Progress Toward the Zero Hunger Goal in Cross-Boundary Climate Change Hotspots

The most recent 2017 United Nations’ Sustainable Development Goals progress report highlighted the need to accelerate the pace of progress in order for the Sustainable Development Goals to be fully achieved. Responding to these concerns, the present commen tary proposes four distinct, but interrelated approaches to accelerate the Zero Hunger G oal in transboundary climate change hotspots, regions which suffer from multiple stressors and vulnerabilities, and in which prevalence of food insecurity and malnutrition often remains disproportionately high. These conceptual, programmatic and policy approaches are discussed drawing from a newly developed conceptual framework and referring to specific examples from climate change hotspots around the world.

Mapping interactions between the sustainable development goals: lessons learned and ways forward

Pursuing integrated research and decision-making to advance action on the sustainable development goals (SDGs) fundamentally depends on understanding interactions between the SDGs, both negative ones (“trade-offs”) and positive ones (“co-benefits”). This quest, triggered by the 2030 Agenda, has however pointed to a gap in current research and policy analysis regarding how to think systematically about interactions across the SDGs. This paper synthesizes experiences and insights from the application of a new conceptual framework for mapping and assessing SDG interactions using a defined typology and characterization approach. Drawing on results from a major international research study applied to the SDGs on health, energy and the ocean, it analyses how interactions depend on key factors such as geographical context, resource endowments, time horizon and governance. The paper discusses the future potential, barriers and opportunities for applying the approach in scientific research, in policy making and in bridging the two through a global SDG Interactions Knowledge Platform as a key mechanism for assembling, systematizing and aggregating knowledge on interactions.

Wasser- und Nährstoffhaushalt im Einzugsgebiet kleiner Fließgewässer auf repräsentativen Flächen im ländlichen Raum des Saarlandes als Grundlage für angepasste kommunale Abwasser- und Regenwasserbehandlungskonzepte - WUNEF

Von August 1997 bis Juli 2000 wurden im Auftrag des Ministeriums fur Umwelt, Energie und Verkehr des Saarlandes 7 Einzugsgebiete im landlichen Raum des Saarlandes hinsichtlich des Wasser- und Nahrstoffhaushaltes sowie der Gewassergute untersucht. An den meist kleinen Fliesgewassern wurde mit uber 60 Probenahmestandorten ein dichtes Messnetz zur Beschreibung der Wasserbeschaffenheit eingerichtet. Uber Klimadaten, Bodendaten und parzellenscharfe Nutzungskartierungen wurde die Nitratauswaschungsgefahrdung modelliert und bewertet. Analysen den Bodenwassers und errechnete Sickerwasserfrachten ermoglichten die Berechnung der diffusen Stickstoffaustrage mit dem Bodenwasser. An den Fliesgewassern wurde neben der Beschreibung der raumlichen Variabilitat der Wasserbeschaffenheit (chemische Gewasserguteklassifizierung) der Abfluss an drei Pegeln dokumentiert. Fur verschiedene Einzugs- bzw. Teileinzugsgebiete konnten so die Frachten der Fliesgewasser den Austragen uber das Sickerwasser gegenubergestellt und mit einem N-Bilanzsalden verglichen werden. Die Ergebnisse zeigen, dass aufgrund der schon im Oberlaufbereich vielfach vorhandenen diffusen Belastung und des auch mit dem Bau von Klaranlagen nicht gelosten Problems punktueller Belastungen und teils hoher Versiegelungsflachen Gewassersanierung nur dann effektiv sein kann, wenn verschiedene Masnahmen integriert werden. Als Komponenten einer integrierten Gewassersanierung konnen die immissionsbezogene Abwasserbehandlung, gewasserschutzorientierte Landbewirtschaftung, Regenwassernutzung und -pufferung und eine Verbesserung des Gewasserumfeldes genannt werden. Mit den Untersuchungen wurden fur das Saarland wichtige flachenbezogene hydrochemische Daten erhoben, die dazu beitragen konnen, in die vom Plan zur Abwasserableitung und -behandlung festgelegten Vorgaben fur den landlichen Raum eine situationsangepasste, integrierte Gewassersanierung einzubeziehen.