Editor’s note: This is the first installment of a three-part series on how Hawaii should address climate change and sea-level rise.

During the 2012 Hawaii legislative session, the State Office of Planning will introduce a bill that proposes adding climate change adaptation priority guidelines to the State Plan. These priority guidelines would prepare the state for assessing climate change impacts on various sectors including agriculture, coastal and near shore marine areas, water resources, education, energy, health, and the economy.

Because the State Planning Act generally requires state and county programs, plans, and decision-making to conform to priority guidelines, adopting this measure could be a crucial first step for providing state leadership in addressing climate change adaptation.

Climate change adaptation builds resilience and reduces vulnerability to impacts such as reduced rainfall, increased storm intensity, and sea-level rise — all of which we are experiencing in Hawai‘i. Although Hawai‘i has been a leader in its efforts to mitigate climate change by mandating greenhouse gas emissions reductions and promoting renewable energy and energy efficiency, the state has yet to comprehensively initiate climate change adaptation. Because the United Nations Climate Change Conference in Durban, South Africa, finished last month without establishing binding international commitments for reducing greenhouse gas emissions, policy makers at all levels of government now face added pressure and social responsibility to develop climate change adaptation strategies.

Decision-makers could prioritize sea-level rise adaptation because our economy and way of life rely heavily upon Hawai‘i’s shorelines and beaches. Sea-level rise may worsen existing coastal erosion, high tide flooding, and drainage problems, which already have caused millions of dollars in damage to businesses and homes. Sea-level rise also could increase coastal vulnerability to wave inundation, hurricanes, and tsunamis. Hawai‘i sea levels have been rising for the past century, and rates are expected to accelerate with continued climate change. Scientific research indicates that global mean sea level may rise between 1 and 3 feet or more during this century. Using best-available science, Hawai‘i state and local decision-makers can begin planning for a conservative sea-level rise of approximately 1 foot by 2050 and 3 feet by 2100.

Sea-level rise adaptation generally involves three basic approaches:

  • Accommodation. Adjustment of existing systems to changing conditions (e.g., amending flood-proofing regulations to require or incentivize increased ground-floor elevation of structures).
  • Protection. Hardening of a system in its existing location to withstand impacts from changing conditions (e.g., shoreline hardening such as seawalls and revetments).
  • Retreat. Relocating existing structures to avoid impacts.

The approach or combination of approaches used for adapting to sea-level rise will vary on a case-by-case basis. For example, coastal portions of the Kamehameha Highway on O‘ahu’s North Shore could require protection because the surrounding areas lack adequate space for retreat. On the other hand, the Hawai‘i Islands Land Trust is currently working on purchasing land to accommodate the mauka relocation of a coastal section of the Honoapi‘ilani Highway located on Maui’s lower West Side. The project also would create eight miles of open park space along the shoreline.

Even without comprehensive state leadership, sea-level rise has been “on the radar” in Hawai‘i. The 2010 Kailua Beach and Dune Management Plan, developed by the Department of Land and Natural Resources (DLNR) and the University of Hawai‘i Sea Grant College Program, details goals, objectives, and implementation actions for adapting to sea-level rise on Kailua Beach. Also in 2010, Maui County incorporated sea-level rise adaptation into its county general plan by including policies for restricting development in areas prone to natural hazards, disasters, and sea-level rise. Last summer, 1,608 of 2,169 survey respondents (74.2 percent) on the forthcoming O‘ahu 2035 General Plan Update agreed that policies addressing the effects of sea-level rise are important considerations for updating the plan. The Department of Transportation, Harbors Division, incorporated a study assessing sea-level rise impacts on harbors and surrounding roadways in the August 2011 Hawai‘i Island Commercial Harbors 2035 Master Plan. DLNR has begun planning for climate change impacts on the state’s watersheds to protect Hawai‘i’s freshwater resources in The Rain Follows the Forest: A Plan to Replenish Hawai‘i’s Source of Water (November 2011).

Although these diverse initiatives could provide important guidance and support for future adaptation efforts, comprehensive measures are necessary to ensure safe, efficient, and well-informed use and development of Hawai‘i’s shorelines. In Sea-Level Rise and Coastal Land Use in Hawai‘i: A Policy Tool Kit for State and Local Governments, the University of Hawai‘i Center for Island Climate Adaptation and Policy (ICAP) identifies three major recommendations for state government action to facilitate sea-level rise adaptation, discussed below. The tool kit also details 24 policy tools (planning, regulatory, spending, and market-based), that state and local decision-makers could utilize to begin adapting to sea-level rise, to be discussed in parts 2 and 3 of this editorial series.

Three Major Recommendations for State Government Action

Direct state agencies — by executive order or legislation — to incorporate a sea-level rise benchmark of 1-foot-by-2050 and 3-feet-by 2100 in planning and decision-making. This benchmark would spearhead necessary statewide sea-level rise adaptation planning and could be reevaluated to accommodate updated climate science. The U.S. Army Corps of Engineers now requires consideration of three sea-level rise scenarios in all phases of its civil works projects. In 2008, Governor Schwarzenegger issued an executive order requiring California state agencies to consider a range of sea-level rise scenarios for 2050 and 2100 when planning construction projects in vulnerable areas.

Support expanded sea-level rise research. Further research is necessary for decision-makers and property owners to understand the potential impacts of sea-level rise on a site-specific basis. Researchers at the University of Hawai‘i are currently generating maps that indicate vulnerable areas based on 1-foot increment sea-level rise scenarios up to 6 feet for the State’s entire coastline. Statewide research on sea-level rise variability, risks and vulnerabilities, federal funding and partnership opportunities, and outreach programs would strengthen adaptation efforts.

Designate a lead agency or establish a task force charged with initiating statewide climate change and sea-level rise adaptation planning. Such leadership would facilitate coordination and collaboration between various agencies and stakeholders and promote consistency among adaptation planning efforts. A lead agency or task force could, among other initiatives, create a statewide vision for sea-level rise adaptation.

These state actions would bolster numerous adaptation initiatives at the state and county level and by a range of stakeholders and individuals.