Global sea level rise is accelerating. Currently, it is rising about 3 mm per year, twice the rate of the 20th century. This is a result of atmospheric warming causing glacial and ice cap melting, as well as thermal expansion
Global sea level rise is accelerating. Currently, it is rising about 3 mm per year, twice the rate of the 20th century. This is a result of atmospheric warming causing glacial and ice cap melting, as well as thermal expansion of seawater. Based on best current scientific understanding, we are likely to see at least a 3-4 feet rise in global mean sea level by the end of the century, although this number could be significantly greater.
On Kaua‘i, we are already experiencing a coastal erosion rate of -0.3 meters per year, which will worsen in the future. Chip Fletcher, professor in the Department of Geology and Geophysics at University of Hawaii, writes: “In Hawaii, as the ocean continues to rise, natural flooding occurs in low-lying regions during rains because storm sewers back up with saltwater, coastal erosion accelerates on our precious beaches, and critical highways shut down due to marine flooding.”
Coastline areas will become increasingly inundated by high waves, storms, tsunamis, and extreme water levels.
Fletcher predicts that heavy rains coupled with sea level rise will lead to major flooding issues: “The runoff will raise the water table, the storm drains will be full of seawater except at the very lowest state of the tide, and standing pools of water will accumulate throughout the region without a place to drain. Travel will be limited and many lands will turn to wetlands, there may be some areas of permanently standing water.”
Climate change and related sea level rise are already taking place — we must simultaneously mitigate impacts by reducing our carbon footprint and learn to adapt. An “adaptation response strategy” has the potential to moderate harmful impacts of current and future climate variability and change.
Currently, a majority of policy making and planning does not incorporate available scientific understanding on climate change and adaptation thinking. For example, the state recently invested $842 million in harbor improvements without taking into account scientific data on sea level rise that will impact this new infrastructure. A notable exception is Kaua‘i’s Shoreline Setback rule, one of the most scientific in the country. By choosing to adapt today, we will build community resiliency for tomorrow.
In assessing adaptation strategies, we can consider the cost of doing nothing contrasted to the cost of action. As Maxine Burkett of UH Manoa pointed out at the 2009 Hawai‘i Conservation Conference, a recent study revealed that a $2.5 million investment in preparation could have offset $500 million in damage costs resulting from Hurricane Katrina.
Suggested adaptation strategies covered at the Hawai‘i Conservation Conference included: every Environmental Assessment and permit process should address sea level rise risks; design building codes to meet risks; identify beach preserves where there will be no “re-build” as further erosion occurs; revisit land use policy as new information comes in, and leave room to be flexible; decentralize energy and water treatment facilities; fill critical gaps in scientific understanding; and get serious about food security.
As articulated by many diverse voices in our community, food security is an imperative part of both community resiliency and sustainable economic development. Adapting to climate change in our local food production system requires planning for less rainfall, salt water intrusion into aquifers, and extreme weather events. It also means a reduction in fossil-fuel use, which translates to fewer imports, including many agricultural inputs that we are highly dependent upon.
Facing the challenges of climate change will require community-by-community decision-making. It is up to each community to decide what they value most, and where their priorities lie. This process will only be successful if it is truly open, inclusive, and equitable.
For more information visit www.malamakauai.org
• Andrea Brower is a Project Manager at Malama Kaua‘i, an organization committed to the ‘aina, community, and culture of the island.
