A recent round of federal funding cuts included the termination of a $3 million grant from the Office of Naval Research to the University of Hawaiʻi at 惭腻苍辞补. The grant, awarded to Chip Fletcher, interim dean of the (SOEST), supported the (CRC), which provided data and high-resolution modeling of sea level rise impacts, heat exposure and precipitation extremes—critical tools that inform decisions made by state and county agencies, urban planners, infrastructure designers, and emergency managers.

“The loss of federal funding for Hawaiʻi鈥檚 climate and sea level rise research will have devastating consequences for the state鈥檚 ability to plan, adapt and protect its people and resources,” said Fletcher.

“The models we develop and their supporting databases underpin key pieces of Hawaiʻi鈥檚 climate legislation and coastal permitting regulations, including assessments of flood risk, groundwater inundation, coastal erosion, coastal construction setbacks and public safety. Without sustained federal investment, Hawaiʻi will lose its capacity to provide accurate climate projections tailored to island topography, severely hampering our preparedness for compound hazards such as king tides, rain-at-high-tide flooding and storm-driven flooding.”

CRC employed 15 people, including graduate students, climate researchers, policy experts and geospatial analysts. To prepare for and adapt to the growing threats related to climate change in Hawaiʻi and the Pacific region, this team gathered data and developed new modeling tools that reduce vulnerabilities to community and infrastructure on the island of Oʻahu.

Specifically, the CRC team has been modeling the impacts of sea level rise including flooding, coastal erosion, drainage failure, wave impacts at higher sea level and groundwater pollution with higher sea level.

Data guides land management, policies

Various state laws and policies rely on CRC data and models: construction setbacks on Maui, Kauaʻi, and Honolulu; mandatory disclosure of sea level rise impacts in real estate transactions; Special Management Area designations on Maui and Oʻahu; Kauai County sea level rise constraint district; and the required analysis of sea level rise impacts in state Environmental Policy Act, including environmental impact statements and environmental assessment permits.

“The loss of these data systems will undermine the scientific foundation of climate resilience policies, stall progress on community adaptation, and increase the vulnerability of coastal populations, public infrastructure, and cultural heritage,” Fletcher emphasized. “Maintaining federal support is not just about sustaining science—it is about safeguarding Hawaiʻi鈥檚 future.”

—By Marcie Grabowski

Oʻahu鈥檚 sandy beaches are at risk. New research from the (CRC) at the University of Hawaiʻi at 惭腻苍辞补 determined that 81% of Oʻahu鈥檚 coastline could experience erosion by 2100, with 40% of this loss happening by 2030. These forecasts of shoreline erosion are more extreme than previous studies indicated for Oʻahu. The study was published in .

“Our findings reiterate the already observed threat of coastal erosion as a hazard to sea level rise in Hawaiʻi,” said Richelle Moskvichev, geospatial modeler at CRC in the 东精影业 惭腻苍辞补 (SOEST) and lead author of the study. “In rapidly eroding areas, communities may see damage to roads, homes or underground infrastructure. Shorelines along the north shore and east side of Oʻahu that are backed with hard-armoring, such as seawalls, could experience total beach loss.”

Creating erosion predictions

To create erosion predictions, the team of researchers used a computer model that incorporates about 30 years of satellite imagery, as well as aerial and drone imagery. The new model also directly accounts for the seasonal movement of sand. For example, when large swells arrive in the winter on Oʻahu鈥檚 north shore, sand is transported from one part of the beach to another.

Given prior modeling efforts, the team鈥檚 own survey observations and anecdotal evidence from residents, the researchers expected to see erosion predicted for many sandy beaches around Oʻahu.

“By including additional satellite data and seasonal modeling, our forecasts show that erosion will increase by nearly 44% above our previous estimates in the short-term, meaning that we anticipate more severe erosion sooner,” said Moskvichev.

Coastal erosion can limit beach access, damage fragile ecosystems and infrastructure, and destroy homes.

“This study provides an update on potential areas of shoreline change around Oʻahu, and can inform long-term development planning for coastal communities and infrastructure of the island,” said Chip Fletcher, interim dean of SOEST, director of CRC, and senior author of the study. “This 东精影业-led research provides science-backed data to those who create local adaptation strategies, and ultimately to those most affected by the forecasted hazards. With improved forecasting for erosion hazard zones around the coast, communities, planners and policymakers can create targeted mitigation and adaptation efforts.”

The research team plans to expand their modeling efforts to the other Hawaiian Islands so that similar predictions are accessible to planners and communities on all islands. Additionally, they plan to use the results in conjunction with other hazard predictions, such as flooding and groundwater inundation, to analyze overlapping locations and timing of risk to communities.

Nearly $1 million was appropriated to the (Hawaiʻi Sea Grant) for the development of a beach and dune management plan for the North Shore of Oʻahu, specifically focusing on the area between Sunset Beach and Sharks Cove.

An important component of the project is community engagement and outreach so that the outcomes and pilot demonstration projects are aligned with community values, concerns and needs. In addition to developing the beach and dune management plan, pilot projects focusing on public infrastructure such as beach access stairs and decks will be discussed.

“This effort serves as a significant coastal management action plan reflecting the values and priorities of the North Shore community,” said Dolan Eversole, Hawaiʻi Sea Grant鈥檚 coastal management specialist and project lead. “In addition to the development of recommendations for site-specific beach and dune management practices, the plan will establish the scientific, environmental, and economic foundation for future evaluation of appropriate adaptation strategies for this critically important resource.”

Gov. Josh Green signed , which provided the funding in a ceremony held at the Hawaiʻi State Capitol on July 8. The ceremony included 16 bills that expand the state鈥檚 efforts to preserve 贬补飞补颈ʻ颈鈥檚 natural resources and foster sustainable tourism. While HB2248 focuses on 翱ʻ补丑耻鈥檚 North Shore, the bill serves as an important coastal management, adaptation planning, and community engagement model for coastal communities within and outside of Hawaiʻi struggling with sea-level rise and other coastal hazards.

“These bills represent significant steps forward in safeguarding 贬补飞补颈ʻ颈鈥檚 environment and promoting responsible tourism,” said Green.

Hawaiʻi Sea Grant will have 1.5 years to develop the recommendations for increased conservation of the beach and dune area. It will draw on similar community-based beach and dune management plans that it developed for Maui County, Kailua Beach Park on Oʻahu, Windward Oahu Tourism Assessment and the Hawaiʻi Dune Restoration Manual.

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—By Cindy Knapman

A provides predictions of coastal flooding in West Maui under various scenarios of sea-level rise and a range of wave events for community members, property owners, businesses, as well as state and county officials. The West Maui Wave-Driven Flooding With Sea Level Rise tool was created by researchers at the (PacIOOS) based at the University of Hawaiʻi at Mānoa.

The combination of high sea levels and large swells can result in significant coastal erosion, damage to infrastructure and properties, and land-based sedimentation that impairs coastal water quality. Hawaiʻi has experienced an increase in wave plus tide-driven flooding in recent years, and these events are expected to grow in numbers and duration due to sea-level rise and changing wave energies.

“Along with other planning tools, we hope these scenarios that are tailored for West Maui will be useful to inform land use planning,” said Tara Owens, co-investigator on the grant that funded this work and extension specialist with .

The public is invited to learn about this new tool on August 30, 4–5 p.m. to receive log-in information.

Factors impacting West Maui

The water level—and the associated risk of coastal flooding—in West Maui is impacted by several factors that are included in the flooding product: daily tidal cycles, long-term sea-level rise, moderate to large wave events, and the slowly-oscillating ocean sea level height around Maui (caused in part by El Niño). PacIOOS, based at 东精影业 惭ā苍辞补鈥檚 , created the new West Maui Wave-Driven Flooding With Sea Level Rise tool by adopting a next-generation modeling approach to combine these factors and augment the annual high wave flooding model represented in the .

In addition to chronic coastal erosion leading to severe damage of properties, wave overtopping and flooding also pose a major safety concern to infrastructure, in particular to Honoapiʻilani Highway, the major access corridor to West Maui.

“Coastal managers and planners in Hawaiʻi rely on science-based information that can support decision making,” said County of Maui Coastal Planner Jim Buika. “This scenario-based tool is powerful because it is locally specific and easy to use. It can guide us to promote sustainable land use and environmental protection.”

The wave flooding tool and a related in West Maui were developed by PacIOOS through a collaborative effort led by the Coastal Hazards Group in the Department of Oceanography at 东精影业 Mānoa, and funded by the National Oceanic and Atmospheric Administration grant “” (award #NA17NOS4730143).

–By Marcie Grabowski

To address the impacts of climate change on Oʻahu, the (Hawaiʻi Sea Grant) is highlighting efforts its experts are conducting around the island to tackle issues surrounding sea-level rise, coastal erosion and inland flooding.

On a field trip to 翱ʻ补丑耻鈥檚 North Shore and Māpunapuna organized by Hawaiʻi Sea Grant on July 29, 东精影业 students and visiting fellows witnessed the impacts of climate change in Hawaiʻi.

Shellie Habel, a coastal geologist and extension faculty at Hawaiʻi Sea Grant, led and organized the site visit and extended opportunities for the five participants to learn more about coastal resilience and planning activities.

“It鈥檚 really important that these participants see present day impacts of sea-level rise because they will be contributing to environmental management as part of their future careers,” said Habel. “Today we observed the manifestation of impacts in the form of erosion and drainage related inland flooding, which are often not intuitively associated with sea-level rise.”

Participants saw firsthand the coastal erosion that is taking place at Rocky Point. Homeowners are using shoreline hardening measures to help save their homes, but Habel said that was only a short-term solution to what will become a dire problem as climate change and sea-level rise continue in the future.

“Visiting the North Shore and Māpunapuna reminded me of the extremely difficult challenges that Hawaiʻi faces as sea-level rise and blue sky flooding gets more frequent and harder to manage,” said Cuong Tran, a graduate student in 东精影业 惭ā苍辞补鈥檚 urban and regional planning program in the and 2022 Grau Fellow. “To adapt to the climate crisis, we all must work together and be able to make tough decisions. I am optimistic that we will find creative solutions through the collaborative efforts put in by government, institutional and community partners.”

• See more 东精影业 News stories on climate change.

Challenging the next generation of leaders

Participants were given the opportunity to ask questions and engage in dialogue with Habel. She challenged them to brainstorm innovative solutions as they become the next generation of environmental managers who will continue to address the challenges of climate change.

“I’m extremely grateful to Shellie for taking time to bring us to see the endangered site on the North Shore—seeing these situations in person evokes such a visceral response that inspires me to continue in this field (environmental policy/administration) and to foster the relationships that need to exist in order for us to protect coastlines and coastal communities,” said Sarah Chin, a visiting 2022 Rappa Fellow from Columbia University.

The field trip included a quick stop through 翱ʻ补丑耻鈥檚 industrial district in Māpunapuna to see the effects of inland flooding in low-lying areas. King tides and higher water levels are becoming more frequent and provide a snapshot of the future and what could eventually become commonplace.

“It is crazy to see the erosion on the North Shore and the inland flooding in Māpunapuna because those sites are indicators of how sea-level rise will impact the island,” said Joel Burgess, a third year law student at 东精影业 惭ā苍辞补鈥檚 and 2022 Rappa Fellow. “The biggest takeaway for me is that climate change is already here, so we cannot afford to waste any more time to take action.”

The reactive and piecemeal approach historically used to manage beaches in Hawaiʻi has failed to protect them, according to a by researchers in the at the University of Hawaiʻi at Mānoa (SOEST). The study also found that if policies are not changed, as much as 40 percent of all beaches on Oʻahu could be lost before mid-century.

In an era of rising sea-level, beaches need to migrate landward, otherwise they drown. Beach migration, also known as shoreline retreat, causes coastal erosion of private and public beachfront property. Shoreline hardening, the construction of seawalls or revetments, interrupts natural beach migration—causing waves to erode the sand, accelerating coastal erosion on neighboring properties, and dooming a beach to drown in place as the ocean continues to rise.

The team of scientists, led by graduate researcher Kammie Tavares in SOEST鈥檚 , assessed the shoreline around Oʻahu that would be most vulnerable to erosion under three scenarios of sea-level rise—all estimated to occur around mid-century.

Shoreline hardening and beach loss

They identified the location and severity of risk of shoreline hardening and beach loss, and a potential timeline for the increase in erosion hazards. The most threatened properties fall into an “administrative erosion hazard zone,” an area likely to experience erosion hazards and qualify for the emergency permitting process to harden the shoreline.

“By assessing computer models of the beach migration caused by 9.8 inches (0.25 meters) of sea-level rise, an amount with a high probability of occurring before mid-century, we found that emergency permit applications for shoreline hardening to protect beachfront property will substantially increase,” said Tavares.

According to co-author Tiffany Anderson, assistant researcher in the Department of Earth Sciences, “We determined that almost 30 percent of all present-day sandy shoreline on Oʻahu is already hardened, with another 3.5 percent found to be so threatened that those areas qualify for an emergency permit today. Our modeling indicates that, as sea-level rises about 10 inches (0.25 meters) by mid-century, an additional nearly eight percent of sandy shoreline will be at risk of hardening—meaning at that point, nearly 40 percent of 翱ʻ补丑耻鈥檚 sandy beaches could be lost in favor of hardened shorelines.”

“In another , we showed that accelerated erosion on neighboring properties, called flanking, usually leads to additional shoreline hardening, and condemns entire beaches,” said co-author Chip Fletcher, associate dean and professor in SOEST. “It is clear that management decisions made today, and during the careers of most of today鈥檚 natural resource managers, will be critical in determining if future generations will inherit a healthy shoreline, or one that has been ruined by seawalls, and other types of shoreline hardening.”

Continue reading on .

–By Marcie Grabowski

The first construction project in Waikīkī Beach in 50 years, which marks the beginning of a new era of renewal and recovery, started with the replacement of the Royal Hawaiian groin. Built in 1927, the original curving cement wall was built to prevent erosion. The new rock groin is replacing the old one with a similar role and function but is much more robust, providing a more stable beach and will be followed by more beach improvement projects including additional beach sand over the next several years.

The replacement groin is designed to maintain the approximate beach width of the 2012 Waikīkī Beach maintenance shoreline nourishment project. No enlargement of the beach or additional sand nourishment is involved in this project.

During this project, the (Hawaiʻi Sea Grant) played an essential role in providing technical project management and coastal science and policy support to the (WBSIDA) which serves as a public private partnership with the state paying for 50 percent of the $1.5 million project cost.

The project began in early May and is expected to be completed in late July. Originally scheduled for September 2020 to avoid the busy summer season, it was accelerated after the COVID-19 pandemic shut everything down and presented a once-in-a-lifetime opportunity to do heavy construction without interfering with hotel or recreational beach activities.

Dolan Eversole, the Waikīkī Beach management coordinator with Hawaiʻi Sea Grant, coordinated with stakeholders and agencies involved and conducted regular project oversight and environmental monitoring, while also serving as technical project oversight on behalf of the Department of Land and Natural Resources (DLNR).

“This project improves the resilience of this beach and will stabilize an extremely important and valuable natural resource,” said Eversole. “Stabilizing the beach system will also reduce the amount of sand migrating offshore which can cause problems for the coral reefs and surf sites if unmanaged.”

The Royal Hawaiian groin was more than 90-years-old and at risk of failure due to deterioration. Structural engineers determined it was leaking sand and contained large voids, cracks, bowing and no apparent internal reinforcement. Its failure would have resulted in the destabilization and eventual loss of more than 1,700 feet of sandy shoreline located east of the groin.

• Related 东精影业 News story: 东精影业 Sea Grant called on to help save Waikīkī Beach, June 17, 2019

The new structure was built around the remnants of the old vertical wall groin and constructed in an L-shaped design. The replacement groin serves to stabilize the beach in the western end of the Royal Hawaiian and will mitigate the extreme seasonal beach erosion which has become more frequent recently in that area.

“Looking ahead, we are actively working with the DLNR on an Environmental Impact Statement (EIS) and master plan for Waikīkī Beach that includes resilient design features that account for future sea-level rise and the acceleration of beach erosion, this type of planning for future conditions is a crucial part of designing and supporting resilient communities and economies and demonstrates the successful partnership that has developed between 东精影业, the WBSIDA and the DLNR,” said WBSIDA President Rick Egged.

A successful partnership

The important 东精影业 partnership with WBSIDA and the DLNR to improve and manage Waikīkī Beach has proved to be successful. Hawaiʻi Sea Grant continues to provide scientific and technical support and outreach to a wide variety of Waikīkī stakeholders and government officials. Hawaiʻi Sea Grant also conducts regular outreach, education and policy review for issues such as climate change, sea-level rise, coastal erosion, beach and reef management and now economic recovery.

“The University of Hawaiʻi plays a key role in serving as a respected neutral broker of coastal science and beach management policy and practice,” said Eversole. “The community in Waikīkī can access all kinds of information and ask questions through the extension and outreach provided by the university. It also serves in an important role conducting environmental and economic research, science, engineering and coastal management policy to better observe and provide information that assists decision-makers in improving the management of the area.”

Additional details on the Royal Hawaiian Groin project can be found at .

—By Sarah Hendrix

A global tendency for future sea levels to become more variable this century as oceans warm, due to increasing greenhouse gas emissions was identified by a team of researchers at the University of Hawaiʻi at Mānoa (SOEST). Sea-level variability alters tidal cycles and enhances the risks of coastal flooding and erosion beyond changes associated with sea-level rise.

Sea-level rise is occurring as Earth warms due to two main factors: melting of land-based ice such as glaciers and ice sheets, and the expansion of seawater as it warms鈥攖ermed thermal expansion. Previously unknown was whether the rate of thermal expansion, which accelerates with warming, will also affect the variability of sea level.

In a , a team led by Matthew Widlansky, associate director of the , assessed future sea-level projections from global climate models. The team found that while future sea-level variability changes are uncertain in many locations, nearly all of the 29 models they analyzed agreed on an overall tendency for the variability to increase on seasonal-to-interannual timescales.

“Whereas it is well understood that the rate of global mean sea-level rise will accelerate with future warming, in part due to the oceans expanding faster at higher temperatures, it was previously unexplored how this nonlinear thermal expansion property of seawater will affect future sea-level variability,” said Widlansky.

“Following thermodynamic laws, sea-level variability increases in a warmer climate because the same temperature variations, for example related to the seasonal cycle, cause larger buoyancy and sea-level fluctuations,” added Fabian Schloesser, a researcher at the 东精影业 Sea Level Center who collaborated on the study.

In places where changes due to ocean thermodynamics and other climate variability processes align, the team found the largest increases in future sea-level variability.

Coastal flooding occurs increasingly often due to a combination of slowly rising sea levels and ocean variability. The new findings therefore further emphasize the importance of sea-level monitoring and forecasting.

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–By Marcie Grabowski

The results of a collaborative research project led by a graduate student at the have been , a website where the public can find information and tools to understand and address climate risks. The case study also has been published regionally on the .

The 东精影业 Hilo study examines shoreline migration on Hawaiʻi Island and combines historic aerial photos, current drone imagery and topographic surveys to discover coastal changes around Hawaiʻi Island. The project is being used by county planners and policymakers to develop a more comprehensive and effective coastal development plan.

The published case study, “,” is co-authored by Scott Laursen, program specialist at the , and Bethany Morrison, a planner on land use with the County of Hawaiʻi who collaborated on the research.

“We do not have adequate knowledge of Hawaiʻi Island鈥檚 shoreline to be able to assess and adapt to the vulnerabilities from sea level rise and related hazards,” Morrison explained. “The goals of this project will help us to address these challenges. More specifically, Hawaiʻi County will have a first phase of shoreline change rates and sea-level rise projections for three different types of shorelines.”

In May 2018, the research team presented their findings to the county planning department, which administers planning regulations for the entire island and provides technical advice to the mayor, planning commission and county council. Based on analyses at Hāpuna, Honoliʻi and Kapoho, the team suggested ways the county could use scientific data to create place-based setbacks.

“Directly involving local professional networks within every stage of the scientific method roots research products within the place-based experiences of these natural and cultural resource managers,” Laursen explains in an email. “[This] increases the probability that these products will be utilized.”

Looking to the future and the uncertainty associated with climate change, the combined results of the completed study will be used to develop policies that are increasingly adaptive to present and future coastal change.

—By Susan Enright