Scientific Programme Deltas in Depth
In scientific workshops, scientists from all over the world present their findings. Sessions will take place in the afternoon of Wednesday 29 and Thursday 30 September, and on Friday morning 1 October. The best papers will be selected for publication in scientific magazines.The programme is structured around the following nine themes:
- Regional climate, sea level rise, storm surges, river run-off and coastal flooding
Convenors: John Church, Wilco Hazeleger, Marcel Stive, Hans von Storch
- Fresh water availability under sea level rise and climate change
Convenors: Eelco van Beek, Gerald Galloway, Ainun Nishat
- Climate change and estuarine ecosystems
Convenors: Peter Herman, Hans Paerl
- Climate change and climate proofing in urban areas
Convenors: Simin Davoudi, Jim Hall, Helmut Mayer,Tejo Spit, Chris Zevenbergen
- Competing claims and land use in Deltas under climate change
Convenors: Fu Congbin, Saleemul Huq, Paul Opdam, Martin Wassen
- Governance and economics of climate adaptation
Convenors: Stéphane Hallegatte, Ekko van Ierland, Katrien Termeer, Elizabeth Wilson
- Decision support instruments for climate adaptation policy
Convenors: Suraje Dessai, Piet Rietveld, Kerry Turner
- Climate and health in Delta areas
Convenors: Andrew Githeko, Pim Martens
- Managing extreme weather risks
Convenors: Myles Allen, Jeroen Aerts, Reimund Schwarze, Swenja Surminski
Climate will change in the next century and beyond due to emissions of greenhouse gasses, aerosols and natural forces. Especially for low lying deltas this brings challenges. The magnitude of climate changes and their effects are uncertain. That uncertainty increases with smaller spatial scale. To develop ways to manage flood risks, insight into uncertainties is necessary.
Observations of past changes and comprehensive climate models are used to construct scenarios of regional climate changes that affect deltas. In this session we will focus on sea level changes, storm surges and river run off. These climate effects are not uniform over the earth. Sea level will differ from region to region due to variability in the heat uptake and to effects of gravitation. Strong storm surges driven by hurricanes in tropical areas have different characteristics than those driven by mid-latitude storms. Interaction with the local bathymetry will impact the effect of surges. River run off is also regionally dependent on the precipitation regimes and land conditions. Except for the regionalization of climate effects, this session will address multivariate aspects of sea level rise, storm surges, and river run off.
Specific issues on which we welcome contributions are:
- Regionalization of future sea level scenarios, including contributions of the thermal expansion, ice discharge and gravitation
- Future changes in storm surges and interaction with local bathymetry
- Changes in precipitation regimes and associated river run off
- Analyses of multiple threats to coastal areas and deltas due to climate change
- Measuring/recording climate change induced change
- Uncertainty analyses for risk management strategies
Scientific evidence is mounting about increased frequencies and magnitude of droughts in the future. Drought periods in deltas are expected to last longer and occur more often as a result of climate change. As deltas lie downstream in river basins, problems of drought will be aggravated by intensified fresh water intake upstream.
For deltas, an even more serious threat might be salinization of soil and water systems as a result of sea level rise. Salt intrusion in river branches will move upstream, threatening fresh water intake points. Sea level rise will also result in increased salt and brackish water seepage in the delta. The salinization of arable land requires higher flushing demands with fresh water. However fresh water availability will decrease dramatically, while at the same time the demand for fresh water will increase due to higher evaporation and longer periods of low rainfall. Moreover, socio-economic developments will increase the demand for public and industrial water supply.
Water managers, in particular those in deltas, can choose two strategies: to ‘fight’ against these trends, for example by taking technical measures, or to accept them and try to find a new balance between demand and supply. The demand can be decreased by reducing water intensive activities or by introducing less drought and salt sensitive agricultural practices.
This theme covers research about impacts of climate change on land use due to drought and salinization in deltas and how deltas can be adapted to the new conditions. This includes research on low river flows, increased salt intrusion and their effects on land use; options to decrease demand; and technical, economic and spatial planning measures that can be applied to match demand and supply. This might include the link with developments upstream and possible solutions that can be found at the scale of river basins.
3. Climate change and estuarine ecosystems
Convenors: Peter Herman, Hans Paerl
Estuaries are semi-enclosed coastal bodies of water which have a free connection with the open sea and within which sea water is mixed with freshwater from land. Despite their limited surface area, estuaries play a critical role in the functioning of the planet. They are highly productive, provide habitat to migrating animals and breeding and nursery space to marine and freshwater organisms. Besides, they are biogeochemical reactors filtering fluxes of nutrients and organic matter from land to ocean.
With high percentages of the world’s population concentrating in coastal areas, estuarine ecosystems are threatened by physical modifications such as land reclamation, dredging or harbor construction. This is amplified by sea level rise, causing 'coastal squeeze': the disappearance of shallow and intertidal areas. In addition, a recent increase in the frequency and intensity of tropical cyclones and temperate storms (i.e. "Nor'easters") is strongly impacting hydrology, water quality and habitat condition of estuaries and downstream coastal waters. Growing demands on the planet's limited supplies of freshwater, eutrophication, pollution and climate change will change both the estuarine biogeochemical cycling as well as the functioning and composition of the ecosystems. These in turn will modify the goods and services delivered by estuarine ecosystems.
In this theme presentations will be given that evaluate the ecological functions and socio-economic values of estuarine ecosystems and their possible change in the context of climate change.
Climate change influences cities and their surrounding areas. Adaptation of urban patterns, public space and the water system, and of houses/buildings is essential to keep cities pleasant to live in over the years and to protect them from social dislocation and discomfort. One can distinguish four important components in this theme:
- the urban climate system itself
- the sensitivity, impacts and vulnerability of the urban area
- short term adaptation measures and longer term strategies
- governance and the adaptive capacity of actors in urban areas to cope with climate change and adaptation
These components are related to knowledge about the changing climate of urban areas, how much it matters (sensitivity), and adaptation measures linked with the quantification of impacts. The last component deals with the governance issues of planning and implementation of adaptation to climate change.
Adaptation measures and governance of adaptation in urban areas can only be understood within the framework of the complexity of urban areas. Governments and other actors constantly have to deal with numerous other pressures on space in urban and metropolitan regions, such as the development of housing, industrial parks, jobs, accessibility etc. Interests and claims meet one another not only at different spatial levels, (neighbourhood, municipal and metropolitan), but also between those levels. A characteristic phenomenon of the complexity of the urban environment is the contradiction between fragmentation of problems, interests etc. and the comprehensiveness of adaptation to climate change.
This theme covers the broad range from local climatic conditions in urban areas, the impact of climate change on the city and adaptation measures to cope with heat waves, drought or heavy rainfall. The theme covers also governance aspects urban adaptation. The focus is on cities and mega-cities in delta-areas.
5. Competing claims and land use in Deltas under climate change
Convenors: Fu Congbin, Saleemul Huq, Paul Opdam, Martin Wassen
A most prominent characteristic of delta regions is high pressure on land because of high competition for space due to urban development, agriculture, nature and leisure. Transport infrastructure, utility and energy networks also claim increasingly larger space. Due to climate change flood protection measures, both coastal and along waterways require more space than in the past (“room for water”), and require changes in land use at the river catchment level to increase the potential of the landscape for water retention. At the same time climate change affects agricultural systems through drought, higher temperatures and salinization. On top of that urban populations attribute great value to ecosystem and landscape services. Adaptive strategies are needed to keep deltas productive and attractive.
Defining which changes in the physical system are technically effective, socially acceptable and economically profitable is a complicated task. Here science has to cooperate with practice, and generic knowledge has to be integrated with local context-specific knowledge. The many uncertainties in predicting the impact of climate change add another layer of complexity to the decision-making on land system change. These complexities demand science-based approaches that can deal with collaborative planning and design.
The theme covers recent research on impacts of climate change on land use in deltas. It also covers research on urgent situations and options for delta regions, being multifunctional and multi-scaled social-physical systems, to adapt to climate change.
6. Governance and economics of climate adaptation
Convenors: Stéphane Hallegatte, Ekko van Ierland, Katrien Termeer, Elizabeth Wilson
Next to the enormous technical challenges, adaptation is a matter of economics and governance. Investments in adaptation are not merely matters of infrastructural adjustments, but will involve processes of change within many social and policy domains such as agriculture, urban and regional planning, nature preservation and energy supply. Since we have distanced ourselves from the perspective of a malleable society created by a central government, governance includes structures and processes between governmental, business and civil society actors ultimately aiming at the realization of collective goals. This session is organized to discuss the economics of adaptation, to find out which forms of governance could increase the implementation of behavioural and infrastructural adjustments and to discuss how the transition towards climate proof regional development can be fostered.
Governance of adaptation is a so called 'wicked' problem. It involves many challenges: the multi-actor challenge because many actors and institutions are involved with different stakes, resources and strategies, the multi-level challenge because which geographic level to address which adaptation tasks is unclear; the multi- scale challenge because climate adaptation requires a constant alternation of short-term action and long-term anticipation; the multi-sector challenge, because many societal sectors are involved and climate adaptation lacks a settled climate policy domain itself and; the multi-perception challenge, because of the uncertainties and the various perceptions about risks, adaptation problems and solutions.
The session is open for papers aiming to contribute to a better understanding of governance and economics of adaptation. The following topics are of special interest:
- Which challenges do public and private partners face when governing for adaptation?
- Which (public and and/or private) governance arrangements or institutional designs are promising to deal with adaptation challenges?
- Which are the conditions that make governance of adaptations successful or likely to fail?
- Which new concepts and theories (complexity theory for example) provide theoretical foundations for our way of thinking about governance of adaptation?
- What are the economic implications of various ways of adaptation?
Decision support for climate adaptation policies concerns three main elements. The first is the assessment of climate change impacts, in particular, ways to deal with uncertainties. Uncertainties enlarge the complexity of decision making processes. Citizens usually require policy decisions based on sound science. However, scientists cannot provide certainty about potential impacts of those decisions due to unpredictable societal and physical processes. One of the ways to deal with uncertainty is the use of scenario methods. Among the issues that are important here is the need for downscaling scenarios and projections of spatial scales that are relevant for adaptation policies.
The second element of decision support methods concerns the generation of promising adaptation options with multiple stake-holders. This may involve the development of models to analyze impacts of adaptation strategies on various stakeholders. In a next step these model results can be integrated with tools to help explore adaptation options and negotiation processes. There are opportunities to incorporate this in user friendly ICT tools such as touch tables.
Finally, decision support tools can be used to evaluate climate adaptation alternatives. Standard tools are social cost benefit analysis and multi-criteria analysis. There are many challenges here, such as the valuation of damage, probability of individual death and group risk as a consequence of climate related accidents or disasters. Other important topics are the determination of the appropriate discount factor to trade-off current and future costs and benefits, and the evaluation of benefits of adaptation policies involving mixed land use to address climate change uncertainties.
Within the theme ‘decision support instruments’ we welcome contributions to each of the three components mentioned above.
To a large extent, public health depends on safe drinking water, sufficient food, secure shelter and good social conditions. A changing climate is likely to affect all of these conditions. The health effects of a rapidly changing climate are likely to be negative, particularly in the poorest communities. Some of the health effects include:
- Increasing frequencies of heatwaves: analyses show that human-induced climate change significantly increased the likelihood of the European summer heatwave of 2003
- More variable precipitation patterns are likely to compromise the supply of freshwater, increasing risks of water-borne disease
- Rising temperatures and variable precipitation are likely to decrease the production of staple foods in many of the poorest regions, increasing risks of malnutrition
- Rising sea levels increase the risk of coastal flooding, and may necessitate population displacement. More than half of the world's population now lives within 60km of the sea
- Changes in climate are likely to lengthen the transmission seasons of vector-borne diseases, and to alter their geographic range, potentially bringing them to regions that lack population immunity and/or a strong public health infrastructure
- Changes in temperature and seasonality may affect peoples health by an increase of pollution levels, of pollen leading to allergic reactions and of new species of plants and animals
Climate change may increase the risk of flooding of rivers in deltas. Immediate effects are largely death from drowning and injuries caused by being swept against hard objects. Medium term effects include increases in communicable diseases caused by ingestion of contaminated water (for example, cholera or hepatitis A) and contact with flood waters (for example, leptospirosis). Heavy rainfall and runoff influences the transport of other microbial and toxic agents from agricultural fields, human septic systems, and toxic dumps. Rainfall can alter the transport and dissemination of microbial pathogens (such as cryptosporidia and giardia), and temperature may affect their survival and growth.
In this session recent research will be presented about the impact of climate change on health in delta regions and on national or local health programmes and interventions that take into account the measures to reduce vulnerability to future climate change in deltas. Papers on all issues mentioned above are welcome.
Risks of weather disasters in urbanized coastal areas are changing because of two main driving forces: variations in the frequency and magnitude of extreme weather events (floods, windstorms, droughts) and socio-economic trends in terms of the number of inhabitants and economic assets at stake. This theme covers the issues that relate both to analyzing and managing vulnerability to climate extremes.
Understanding changes and trends in disasters and their causes are important in order to assess possible response measures. Issues that will be addressed in this session relate to detecting historic trends in climate and weather extremes as well as to detect trends in economic losses. Are these trends related, and what methodologies exist to make the underlying mechanisms more explicit? If we understand their causes, what are appropriate and effective strategies for adapting to changing risks? What research and information is required for analyzing risks, and developing adaptation measures?
Reducing risk is the most important response to manage changing climate extremes. We focus here on reducing economic losses. Think of adjusting building codes, robust waterfront development and other smart architecture to cope with storm and flood risk. In terms of droughts, sustainable water storage can improve resilience to droughts in delta areas. Vulnerability to climate extremes is also determined by the coping capacity of a coastal area city following the event through evacuation, relief and rehabilitation options. In addition, adaptive capacity determines the perspectives for managing risk through research, planning and implementation of measures that reduce risk.
Interestingly, insurance and other financial instruments can play roles in covering and spreading risk of extreme losses. Experience in awareness raising and incentivizing risk reduction through these financial instruments can help in the design of products with benefits beyond mere risk transfer.
Finally, the session will address what additional information and tools are needed from climate and vulnerability science for the management of extreme events? What uncertainties surround the trend analysis of climate extremes? What uncertainties are present in future simulations of climate extremes and losses? How can disaster related risks and their uncertainties be better communicated? Which storm surge early warning systems are effective and which role can they play?
Abstracts about other disaster management tools and about environmental refugees are welcome in this theme as well.