New Research Opportunities in the Earth Sciences - New Research Opportunities in the Earth Sciences - page 70

flooding and the resulting efforts to limit physical and economic damage through site
location and size and to maximize revenue by renting many rooms at a relatively high
price. Using an agent-based model of human activity coupled with a physically based
model for barrier island elevation and evolution, McNamara and Werner concluded
that developed barrier islands are lower lying and farther offshore than undeveloped
islands, that island vulnerability increases when property is insured, and that
protection measures at best postpone widespread damage. This research demonstrates
the high social value of coupled mechanistic agent-based models.
Coastal Landscape Response to Sea-Level Rise and Natural and Anthropogenic
Disturbance
Located at the interface between land and sea, coastal systems are particularly
sensitive to changes in climate and land use because they are subject to forcings from
both ocean and land processes. Climate change effects are pronounced in all coastal
regions from the tropics to the poles and include accelerated sea-level rise; ocean
acidification; and changes in temperature, precipitation, and storm frequency. Both
urbanization and agricultural intensification in coastal watersheds lead to landscape
change, including loss of habitat, nutrient buffers, and protective barriers (islands,
dunes, wetlands) as well as eutrophication effects, including low-oxygen dead zones,
harmful algal blooms, and fisheries' losses. With most of the world's major cities and
more than 60 percent of the world's population living near the coast, these changes
can be expected to have profound societal and economic consequences globally. Yet
our understanding of the impacts of climate and human-induced change on coastal
systems is not well developed due in part to the lack of a large, integrated coastal
research program.
Coastal environments are strongly influenced by the landscape-ecosystem-
human interactions discussed earlier. Close coupling of geomorphic, hydrological,
ecological, climatic, and biogeochemical processes shape modern coastal landscapes
and dictate their sensitivity and resilience to short-term disturbance events and
longer-term trends in climate, land use, and sea level. Changing climate and land use
affect coastal systems at multiple spatial and temporal scales. Understanding the
effects of these external drivers as well as the interactions and feedbacks among
landscape units and processes demands a unifying ecomorphodynamic framework for
investigating these complex systems. Studies of specific coastal environments (e.g.,
barrier islands, marshes, coral reefs, mangroves, seagrasses, estuaries) and their
linkages are necessary to understand impacts at regional and global scales.
Coastal systems face accelerated change associated with climate and land-use
change. At high latitudes, coastal erosion is increasing in response to warming
temperatures, sea-level rise, increasing storminess, and decreasing sea-ice extent
(e.g., Jones et al., 2009). The thawing of coastal permafrost, with associated
decomposition, is likely to result in the release of large amounts of stored carbon to
the atmosphere and major ecosystem changes (Schuur et al., 2008). At mid-latitudes
there is growing concern about wetlands loss and flood risk with rising sea level,
changes in storm magnitude and frequency, and increased temperatures and