Honolulu — Today during a press conference, Mayor Kirk Caldwell issued a formal directive to all city departments and agencies to take action in order to address, minimize the risks from, and adapt to the impacts of climate change and sea level rise. The directive was issued in response to the Sea Level Rise Guidance and Climate Change Brief presented today to Mayor Caldwell and members of the City Council by leadership of the city’s Climate Change Commission.
The Mayor’s directive requires all city departments and agencies under the mayor’s jurisdiction to take several actions, including:
- View climate change and the need for both climate change mitigation and adaptation as an urgent matter, and take a proactive approach in both reducing greenhouse gas emissions and protect and prepare the city for the physical and economic impacts of climate change;
- Use the Sea Level Rise Guidance and Hawai‘i Sea Level Rise Vulnerability and Adaptation Report in their planning, programing, and capital improvement decisions to mitigate impacts to infrastructure and critical facilities subject to sea level rise, which may include elevation or relocation of infrastructure and critical facilities, the elevating of surfaces, structures, and utilities, and/or other adaptation measures;
- Propose revisions to shoreline rules and regulations to incorporate sea level rise and conserve a natural, unarmored shoreline wherever possible; and
- Work cooperatively to develop and implement land use policies, hazard mitigation actions, and design and construction standards that mitigate and adapt to the impacts of climate change and sea level rise.
In addition, the directive strongly encourages independent agencies, city-affiliated entities, and city-related institutions to help advance these efforts and adopt similar initiatives.
“I appreciate the hard work and professionalism of the Climate Change Commission in providing our administration and the City Council these thoughtful, science-based recommendations,” said Mayor Caldwell upon issuing directive 18-01. “This guidance confirms that climate change is the defining challenge to humanity — and to Oʻahu — in the 21st century. By issuing this directive, I want to ensure that every policy and project decision dealing with sea level rise going forward is made in the best interest of the public.”
In its Sea Level Rise Guidance, the commission emphasized that the city should be planning for high tide flooding associated with 3.2 feet of sea level rise by mid-century, and, because of continued high global carbon emissions, take into consideration 6 feet of sea level rise in later decades of the century, especially for critical infrastructure with long expected lifespans and low-risk tolerance. The sea level rise guidelines recommended by the commission are consistent with findings by the Intergovernmental Panel on Climate Change and the National Oceanic and Atmospheric Administration (NOAA).
Based on scientific modeling of sea level rise impacts identified in the Hawai‘i Sea Level Rise Vulnerability and Adaptation Report issued by the State of Hawaiʻi in December 2017, the Commission noted that:
- Nearly 4,000 structures on Oʻahu—the vast majority being homes or businesses—will be chronically flooded with 3.2 feet of sea level rise;
- Of the 9,400 acres of land located within the 3.2 foot sea level rise exposure area, over half is designated for urban land uses, making O‘ahu the most vulnerable of the Hawaiian islands;
- With 3.2 feet of sea level rise, almost 18 miles of Oʻahu’s coastal roads will become impassible, jeopardizing access to and from many communities; and
- Oʻahu has lost more than 5 miles of beaches to coastal erosion fronting seawalls and other shoreline armoring, with many more miles of beach certain to be lost with sea level rise if widespread armoring is allowed.
In an accompanying Climate Change Brief, an independent report that lays the foundation for the Sea Level Rise Guidance, the Climate Change Commission agreed with the overwhelming majority of international scientists that the world is currently on a pathway of warming more than 5.4oF above pre-industrial levels. They concluded this level of warming will be extremely dangerous to humanity, including rapid melting of ice sheets, extreme heating of the tropics, damaged marine and terrestrial ecosystems on which we rely for food and water, superstorms, and disrupted international economic networks. The commission warned that the climate is already shifting in this direction, and without dramatic, broad-based, and immediate cuts in global greenhouse gas emissions, the very worst impacts of climate change will become inevitable.
Specific to the City and County of Honolulu, the commission included in its detailed Sea Level Rise Guidance that rising seas will threaten Oʻahu communities and natural ecosystems in multiple ways, including: increased vulnerability to flooding; land loss and coastal erosion; saltwater intrusion into streams and coastal wetlands; and increased damage when hurricanes, tsunamis, and seasonal high waves strike. The commission further concluded that rising seas will negatively impact local communities, habitats, property, infrastructure, economies, and industry.
The commission, which carefully tracks a combination of international research and local modeling to underpin its decisions, also stressed that impacts from high tide flooding will arrive decades ahead of permanent inundation. Tidal flooding is projected to become more frequent and erode beaches, flood roads, and in times of rainfall bring local transportation to a standstill. According to modeling by NOAA, under their “Intermediate scenario,” flooding exceeding last year’s “king tide” level could be present an average of twice per month in Honolulu before mid-century.
“The voters of Oʻahu established this commission to advise city leadership because they can see first-hand that our climate is changing and we need to act,” said Josh Stanbro, chief resilience officer and executive director of the city’s Office of Climate Change, Sustainability and Resiliency. “This directive will make us stronger and safer, and is an important additional step in our work to create a larger resilience strategy for the entire island of Oʻahu.”
“Coastal communities across the world are grappling with how to address rapid sea level rise due to climate change,” said Dr. Makena Coffman, chair of the Climate Change Commission. “The commissioners and I appreciate that our community has established a process by which science can directly inform decision-making. The city’s leadership has been proactive in understanding the scope of the problems that climate change will create for Hawaiʻi and changing policies to make us more resilient. Embracing the commission’s sea level rise guidance is another step in this direction.”
“As a scientist, father, and grandfather, I am grateful that Mayor Caldwell is acting with courage and speed on the commission’s recommendations,” said Dr. Charles Fletcher, vice chair of the Climate Change Commission. “I am extremely proud that in the City and County of Honolulu, and throughout the state of Hawai‘i, our leadership recognizes that every community must act immediately to reduce global carbon emissions, and to adapt to the climate change risks that are now inevitable. Unless the world joins us, we will all be facing severe and dire consequences.”
For a link to the directive, the letter from the Climate Change Commission to the mayor and City Council, the Sea Level Rise Guidance and Climate Change Brief, and other resources, click here.
Note: The Climate Change Commission, which consists of five members with expertise in climate change in Hawaiʻi, unanimously adopted its Sea Level Rise Guidance and Climate Change Brief on June 5. In accordance with the City Charter, the commission is charged with gathering the latest science and information on climate change impacts to Hawai‘i and providing advice and recommendations to the mayor, City Council, and executive departments as they look to draft policy and engage in planning for future climate scenarios.