Climate Change and the European Water Dimension - Agri ...

Chapter IV.C. Impact of Climate Change on Coastal Systems
IV.C.1. Introduction
Coastal zones, including the continental margin, extend from the coastline to the 200
m bathymetric line and occupy at most 8% of the ocean surface and only 0.5 % of its
volume. Nevertheless, coastal zones include some of the most productive and
valuable habitats of the biosphere, including estuaries, mangroves, lagoons, rocky
shores, sandy beaches, and seagrass meadows. About 90% of the fish catch
originates from the coastal zones that account for 25% of the ocean primary
production. A large part of this carbon production is exported to the open ocean
influencing the carbon cycle of the ocean as a whole.
In addition, the coastal zones represent a wealth of biodiversity and provide a large
variety of natural resources and services that have been continuously exploited by
human population. Nearly 40 to 50% of the human population lives within 100 km
from the coastline including some of the world’s largest cities. The impact of human
activities on the variability of the coastal systems is considerable, usually observed
as negative trends (i.e. decline, degradation) with respect to marine resources,
standing stocks and coastal landscape. Differentiating the effect of climate change
from direct anthropogenic activities is very difficult. The latter, in general, reduces
the resilience property of the coastal system, which then becomes more vulnerable to
stresses due to climate variability.
Coastal zones are transitional areas in which processes are controlled by complex
interactions and fluxes of material between land, ocean and atmospheric systems. As
a result, coastal zones are among the most changeable environments on Earth.
Natural factors that are expected to have the largest impact on coastal systems are
temperature changes, sea-level rise, increasing greenhouse gases in the
atmosphere, availability of water from precipitation and river runoff, wind patterns,
and storminess. In all cases, however, these natural forces are not acting individually
on a specific compartment of the coastal systems, but are interconnected in many
ways and often associated with a human signature of some sort.
Driven by economic interests, the issues and problems related to coastal degradation
and scarcity of marine resources have been receiving an increasing level of national
and international attention over the last 20 years. Regional Conventions for the
protection of the marine environment and coastal areas were created under the
auspices of the United Nations (UNEP) to provide the legal framework for regional
Action Plans, expressing thus political concerns of governments to assess and
monitor the main factors influencing the marine environmental quality. In 1996, the
European Commission implemented a multi-years Demonstration Programme on
Integrated Coastal Zone Management (ICZM) to identify and promote mitigation
strategies in response to a continuous degradation of the coastal environments. As a
result, EU Member States are committed since 2002 to develop strategies for ICZM,
including a number of rules and good practices that were identified in this
Demonstration Programme.
Compliance to these agreements, conventions, laws, and the achievement of their
challenging goals require a sound scientific understanding of how the coastal
systems respond to a broad spectrum of phenomena including its susceptibility to a
increasing human pressure, as well as to steady global climate change. The Joint
Global Ocean Flux Study (JGOFS) was established in 1988 as a core project of the
International Geosphere-Biosphere Programme (IGBP) to assess and understand
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