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 (1 of 2)

 
Introduction
 
Teasing apart impacts due to accelerated climate change and those due to other human activities is conceptually difficult, and indeed from the perspective of promoting concerted sustainability action, probably unnecessary. The set of projects described in this section have the common aim of addressing human modification of the coastal zone, including climate-induced change. Several of these projects recognise the ubiquity of climate change as both causal factor and consequence of the processes being studied. Often climate change is targeted for specific attention because it has the potential to aggravate or synergise with a particular process. In other instances, climate change is taken into consideration as a forcing control.
 
ELOISE projects categorised
 
The influences on nitrogen removal in Europe's estuaries are explored in NICE. Climatic variables (in particular, differences in temperature, length of growing season, and solar irradiance ) are important direct controlling factors, but climate change also has implications for the tidal flushing regime and the biota, also studied in this project, as other key factors determining nitrogen fluxes. The interplay between nitrogen and carbon cycling means that nitrogen management interventions in the coastal zone induce changes in the global balance of carbon dioxide and nitrous oxide (e.g., Welsh et al., 2000), with implications for climate change. More in-depth investigations of seasonality in nutrient cycling have been carried out (Risgaard-Petersen and Ottosen, 2000; Rysgaard et al., 1998), potentially giving higher temporal resolution to climate change impact projections. An interesting premise of the project is that the fate of anthropogenic nitrogen in the aquatic environment is as much a socio-political problem as an environmental one, and the approach taken for the project design has the potential to give valuable insights for future climate change science. A critical issue is the extent to which knowledge from one location or context can be applied to others. In NICE, cross-comparability was an explicit methodological aim, for instance, with the climate effects evaluation drawing on a north/south comparison accommodating different tidal regimes.

ANICE also investigated the cycling of nitrogen in the coastal zone, with a focus on atmospheric inputs. The problem of atmospheric nitrogen inputs (both nitrate and ammonium) is increasingly recognised, and anthropogenic emissions are expected to increase further (e.g., Galloway et al., 1995). The inclusion of aerosol into the nitrogen modelling is an important advance, bridging with climatological studies. Indeed, ANICE was an innovative combination of empirical and modelling work, and it addressed both the larger scale (atmospheric inputs of nitrogen to the North Sea ) and the local scale, with a more detailed assessment of the effects of nitrogen on the coastal area in the southern North Sea . This is shown in Figure 4(a) below.

 

Figure 4(a). The total atmospheric nitrogen deposition to the North Sea in 1999. (Depositions - ton N per km 2). The results reflect to a large degree the distribution of the source areas around the North Sea , but also the distribution of precipitation is important. For example, the large depositions at the Norwegian coast reflect the high precipitation amounts due to the mountains in this region (Hertel et al., 2002).

Figure 4(a). The total atmospheric nitrogen deposition to the North Sea in 1999. (Depositions - ton N per km 2). The results reflect to a large degree the distribution of the source areas around the North Sea , but also the distribution of precipitation is important. For example, the large depositions at the Norwegian coast reflect the high precipitation amounts due to the mountains in this region (Hertel et al., 2002).
 
Both those studies focus on the causes of eutrophication in the coastal zone. CHABADA sought ways to detect and address changes in Mediterranean coastal zone community composition in response to such external factors. The suite of modelled and molecular techniques used to assess changes in diversity is intended to be of use whatever the nature of the alterations of the microbial community.

EULIT also explored population responses to ecosystem change and nutrient enrichment, but of littoral flora and fauna, rather than bacteria. Again, human activities are shown to lead to altered species interactions and succession patterns, and this type of information, scaled across Europe, is important for climate change impacts analyses.

Eutrophication is also a key theme in the EROS21 project, and the studied river-ocean system of the northwestern Black Sea is a highly altered system. Society’s modifications of water flow, chemical composition and sedimentation in the Danube and Dnjestr rivers have been severe. Seasonal patterns in productivity have been determined, along with supporting meteorological data, again linking anthropogenic pressures with climate-related forcing of ecosystem processes.

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