Norwegian Institute for Air Research
Netherlands Institute for Ecology
Tyndall Centre for Climate Change Research
Institute for Environmental Studies, Free University Amsterdam
University of Plymouth
Centre for Social and Economic Research on the Global Environment
Land-Ocean Interactions in the Coastal Zone
 


Climate Change and Coastal Management
Synthesis Results

4. Human Impacts (2 of 2)

 
ELOISE projects categorised
 
EUROCAT, like BASIS, aimed to develop a multi-disciplinary sustainability approach for coastal zone science. While it collated and appraised data on sources and fluxes of different compounds (nutrients and other trace elements) for several European catchments, its focus on integrating these data with related socio-economic data (pertaining to users and consumers of the natural resources and coastal zone functions) lends it the potential for greater applicability, not least in climate change impacts assessment. By bringing together natural science models and socio-economic tools, it aims to provide a broadly usable management tool of interest to a wide spectrum of users (those involved in policy, planning and regulation of coastal zone management) at multiple scales. The consequences of climate change will have mixed impacts on different communities (in both human and natural systems), and EUROCAT offers the potential to seek out optimalities in managing emissions and environmental processes in terms of ecological potential and socio-economic benefit.

This is exemplified by the research undertaken in the UK's catchment, the Humber Estuary (HUMCAT). HUMCAT considers managed realignment of coastal flood and erosion defences as a central component of the various policy options for attenuation of nutrient emissions. Managed realignment involves the deliberate breaching of engineered defences to allow the coastline to recede to a new line of defence further inland ( Figure 4(b)). It is intended to be used as part of an on-going re-assessment of sea defence and coastal protection strategies in the UK in response to the threat of climate change.

The analysis takes as a core starting assumption that managed realignment policy will be an important component of any future planning for the Humber estuary and the catchment. But the key insight highlighted is that managed realignment (and its impact in terms of increased intertidal habitat) carries with it a number of positive externality effects. It creates more habitat with potential biodiversity, amenity and recreational values; a more extensive nutrient and contaminants storage capacity; and a carbon sequestration function. All these potential economic benefits are in addition to its sea defence/coastal protection benefits in terms of increased flexibility in response to sea level rise and climate change and therefore reduced maintenance costs.

 
Figure 4(b). Manages Realignment (Source: English Nature)
Figure 4(b). Managed Realignment (Source: English Nature)
 
From an economic efficiency perspective, the first test of managed realignment requires the scheme or programme to demonstrate net economic benefit, i.e., that compared to a traditional hard engineering "hold the line" sea defence strategy, managed realignment yields an efficiency gain in terms of net benefit or lower overall costs. The analysis demonstrates that for a range of managed realignment schemes around the Humber estuary and tidal rivers, there is a net economic benefit. In this case study, the costs of realignment over a 25 year time period or more are outweighed by the benefits created in terms of savings in maintenance costs and the positive environmental externality effects.

The HUMCAT research concludes that:

  • managed realignment, if implemented on a reasonably large scale, could be an effective way of improving the water quality of the Humber estuary. In the scenarios considered, farming practices throughout the more than 25,000 km 2 of the catchment would have to be radically changed in order to achieve reductions in concentrations of nutrients throughout the estuary comparable to those realised by creating 75 km 2 of new intertidal area around the estuary and tidal rivers by realignment of flood defences;
  • managed realignment has a number of environmental benefits (habitat creation, carbon sequestration, etc.), the value of which can more than offset of the costs associated with this option and can result in substantial positive net present values.

The following ELOISE projects also extend from an analysis of the impacts of environmental change on society towards demonstrations of how society is attempting to address climate change-related impacts on the environment.

In the expectation of accelerated sea-level rise, the outputs of DELOS have immediately accessible benefits to society. Flood and coastal defence investment is a major use of public funds across Europe , and it exemplifies the tensions between the natural and human systems in the coastal zone. Low-crested structures are those coastal defences that are regularly overtopped by waves, and the DELOS project aimed to provide a synthesis of the effects and effectiveness of these artificial breakwaters and reefs. Its validated and calibrated models are important advances in forecasting the effect of low crested defence structures on the littoral environment.

Under conditions of climate change and sea-level rise, transformation of the coastline is inevitable. Increasing erosion of coastal cliffs is projected. From society's perspective, cliff collapses are a hazard, and uncertainty about the triggers of serious collapse leads to technical difficulties for land use planners, limiting the use of coastal lands. The PROTECT project has researched techniques to identify cliffs at risk of imminent collapse, to allow predictions to be made of the timing and extent. In adapting to climate change impacts, this type of applied understanding of natural processes is vital.

HUMOR also addresses the implications of the ongoing degradation of coastal areas across Europe , and has attempted to understand, and predict , the medium to long-term evolution of coastal morphology (over months to years) and its interplay with human actions in the coastal system. Its modelling tools link the complex, multi-scale, often nonlinear dynamics of coastal hydrological and sediment processes which shape the coastline with the human interventions and impositions on the littoral zone (ports and harbours, dredging, and so on). This project thus has tremendous potential to contribute to the science of integration and sustainability.

The OROMA project addresses changes in coastal bathymetry and the related processes of erosion, sediment transport and deposition. Its innovations are new tools for mapping and presenting morphodynamics over large areas in nearly real time. Such tools have the potential to be vital parts of the climate change management toolkit.

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