Geoscience Reference
In-Depth Information
other low-lying regions, would be almost entirely underwater in a “Hurricane
Katrina-like” disaster. h e ARkStorm scenario also indicates that hurri-
cane-force winds would strike the coast, in some places reaching 125 miles
per hour. As slopes and hillsides become quickly saturated, the ensuing land-
slides and mudl ows would cause widespread damage to roads and property.
h is scenario suggests that one-quarter of all homes in California would be
destroyed and an estimated 1.5 million residents would be forced to evacuate
the Central Valley and the San Francisco Bay delta.
h e total cost to California in this scenario, including business inter-
ruption and property repair costs, could reach $725 billion, which is three
times the estimated cost of a large Southern California earthquake. h e
U.S. Geological Survey considers this extreme storm scenario to be the
next disaster waiting to happen—even more catastrophic than the next big
earthquake predicted to strike the region. h e ARkStorm team has raised
public policy questions, including whether to fund emergency preparedness
and atmospheric river-prediction studies, and it recommends that steps to
mitigate the impacts of this scenario should begin immediately to prevent
catastrophic loss of life and property.
We now have the ability, as a society, to understand climate and forecast
weather. We also have deeper insights into the impacts of extreme climate
events on our world. It is time for individuals and society to change our
behavior in order to mitigate the ef ects of these events. One important step
would be to allow our l oodplains, marshes, and deltas to resume their natu-
ral functions. Each year, the oceans rise higher, and some scientists suggest
that the best protection from the dangerous combination of rising sea levels
and extreme storms is what nature has already provided but we have nearly
eliminated: tidal wetlands.
In California before the Gold Rush, for example, the San Francisco Bay
delta was surrounded by 849 square miles of tidal wetlands. Not only did
these wetlands provide unique habitats for millions of migrating and resident
birds, mammals, and i sh, but the lush vegetation also slowed storm-driven
waves, dissipating their energy. Today, only about 48 square miles of the wet-
lands remain, and these remnants are among the most threatened ecosystems
in the state. An urgent question is whether these marshes can keep pace with
the rising sea. h e sediments delivered to the marshes may prove inadequate
to keep the surface above water, and the marshes may no longer have the
option to retreat landward, as they are now completely surrounded by urban
sprawl.
