Vulnerability, Impacts and Adaptation of Coastal Zones to Global Change - Vulnerability of Coastal Ecosystems and Adaptation - page 134

changes in land use and desertification. The main examples of
cumulative global change are: water stresses caused by an
overexploitation of water resources, the degradation and destruction of
a large variety of ecosystems, biodiversity loss, soil retrogression
and degradation, desertification, the disruption of the nitrogen and
phosphorus cycles, pollution of the air, ocean, surface and ground
waters, the increase in the concentration of aerosols of anthropogenic
origin and, more generally, the increasing scarcity of renewable and
nonrenewable natural resources.
4.2. Coastal zones and global systemic and cumulative changes
Among the systemic global changes, the only one that acts strongly
on the coastal zones is anthropogenic climatic change. This change
leads to increases in the global average sea level and in the sea
temperature, to a reduction in the extent of sea ice and to changes in
the acidity, salinity, wave climate and oceanic circulation. We will
have the opportunity to analyze these effects in the following sections.
According to the definition of the United Nations Framework
Convention on Climate Change, anthropogenic climate change or
simply climate change is the change in climate which is attributed
directly or indirectly to human activity that alters the composition of
the global atmosphere and which is in addition to natural climate
variability over comparable periods of time. There are essentially two
types of response to anthropogenic climate change: mitigation and
adaptation. Mitigation measures are human interventions that seek to
reduce the sources or enhance the sinks of greenhouse gases in the
atmosphere; adaptation is the process of adjustment to actual or
expected climate and its effects. In human systems, adaptation seeks
to moderate harm or exploit beneficial opportunities. In natural
systems, human intervention may facilitate adjustment to the expected
climate and its effects. A system's vulnerability to climate change
depends on the character, magnitude and rate of the change,
the variations to which it is exposed, its capacity for adaptation and
the present or future impacts on the system. These impacts depend in
their turn on the sensitivity of the system. For human systems, the
capacity for adaptation rests on several factors that belong to them: