Policy decisions will affect coastal communities' risk more than climate change
Oregon State University
Coastal communities face increasing danger from rising water and storms, but the level of risk will be more closely tied to policy decisions regarding development than the varying conditions associated with climate change, new research by Oregon State University suggests.
The
findings, published in the journal Water, provide an important
framework for managing the interactions between human-made and natural systems
in cities and towns along shorelines as the Earth continues to warm, the
researchers said.
Professor
Peter Ruggiero of OSU's College of Earth, Ocean, and Atmospheric Sciences and
John Bolte, chair of OSU's Biological and Ecological Engineering program, led
the study, which employed a modeling platform known as Envision to quantify the
expected effects of flooding and erosion on buildings and infrastructure as
well as beach accessibility through the remainder of the 21st century.
Using data from Tillamook County along the northern Oregon coast, the researchers plugged into Envision information on landscape characteristics, population growth, development, water level, coastal change models, policy narratives and climate change scenarios.
In
a set of analyses involving many variables, the most important takeaway is the
power of policy measures to positively or negatively affect a coastal
community's climate risk level, Ruggiero said.
Those
measures include the construction of protective structures between the beach
face and the shoreline; adding sediment to beaches where access in front of
those structures has been lost; removing or relocating buildings repeatedly
affected by coastal hazards and turning hazard zones into conservation areas;
constructing new buildings well above the base flood elevation established by the
Federal Emergency Management Agency; and preventing new development in hazard
zones even if those areas are within urban/community growth boundaries.
The
model considered the effects of continuing current development policies,
implementing only policies designed to combat environmental changes, realigning
policies to be more consistent with a changing environment, and relaxing
current policies such that development takes precedence over protecting coastal
resources, beach access and everything else.
"The
combination of climate change and development pressures has the potential to
significantly increase the effects of flooding and erosion on coastal
populations," Ruggiero said. "The strategies used to adapt to these
impacts have the potential to either improve or exacerbate exposure to hazards,
and our modeling results suggest that adaptation policies implemented in
response to coastal hazards will have a greater impact on community exposure
than the range of variability associated with climate change."
He
added that no alternative produced by the model represents a specific forecast
for Tillamook County but rather provides a range of results for decision-makers
there and in other communities to use to try to limit the uncertainty inherent
in climate change adaptation planning.
"Implementing
policies for which the outcome is less certain might not be as desirable as
implementing one that's projected to positively impact one or two important
metrics to the stakeholders under all climate scenarios," Ruggiero said.
"Understanding the impacts of decisions and climate both individually and
coupled within scenarios can potentially allow for better decision-making
regarding adaptation."
The
National Oceanic and Atmospheric Administration and Oregon Sea Grant supported
this research. The collaborators included OSU graduate students Alexis Mills,
Katherine Serafin and Eva Lipiec.