“I’ve known since I was five I wanted to be a marine scientist,” said Tara Owens. She grew up in Tennessee and spent summers along the South Carolina shore. Fast forward, Owens is now 40 and has been a Hawai‘i resident for more than 10 years. In the meantime she received her master’s of science degree in coastal geology from the University of Hawai‘i and is currently a UH Sea Grant coastal processes and hazards specialist assigned to the Maui County Planning Department.
In that capacity it is her job to help the Maui community understand active flooding, passive flooding, erosion, and wave action, and how these and other factors are likely to impact coastal areas throughout Maui County immediately and in years to come.
A new tool for understanding sea level rise is the Hawai‘i Sea Level Rise Viewer (Hawaiisealevelriseviewer.org). This is a web-based map viewer that shows sea level rise models. It resulted from legislative action begun in 2014 that was expanded in 2017 and adopted by the State of Hawai‘i Climate Commission in December 2017.
Though the Sea Level Rise Viewer can be adjusted to show many different scenarios, a composite view with sea level rise set to 3.2 feet was used for this article. The red lines in the visuals (see images below) represent the extent of erosion with 3.2 feet of sea level rise. “This,” Owens said, “is an increase that could occur as early as mid-century.” The area shaded in blue designates places the model predicts will be the high water mark at 3.2 feet of sea level rise, due to a variety of factors including wave action, erosion, and both active and passive flooding. She stressed that sea level rise is an “incremental” event: “It doesn’t happen all at once, and it happens to a greater or lesser degree depending on the underlying conditions.”
She contrasted that kind of change with catastrophic events like floods, tsunamis, or tropical storms which can bring disastrous outcomes in a very short period of time. “Even though 3.2 feet is used as the predicted standard (and the standard on which current proposed county planning setbacks are based), the actual range could be as little as two feet or as much as eight feet by the end of century.”
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Hawaii Business magazine examined this threat in its May 2019 issue, citing research from the National Atmospheric and Oceanic Administration (NOAA). “As seas rise, waves become larger and extend father into land and their impact becomes exponentially greater,” the article read. “Last year’s king tides broke the state’s 112-year record, rising up to 12 inches beyond predicted levels. In addition, the warmer the environment, the more intense and frequent heavy rain events are and the closer hurricanes will come. In 2015 the ocean water around Hawai‘i was 2 degrees warmer than normal and in that year 15 hurricanes approached the island.”
But Owens’ work isn’t all catastrophe and disaster. Dune restoration projects are one of the things that have made her feel good about her work here. “Maui,” she said, “has been recognized for programs in Kihei and Pa‘ia. For example in Lower Pa‘ia, because of the many footpaths to the beach, dunes had been demolished and there was no designated trail. By assuming stewardship, designating trails, and allowing vegetation to recover, the sand returned and the natural shoreline protection increased. I like to think of that kind of approach as the most bang for the buck.
“But,” she added, “even though it worked in Pa‘ia it won’t work everywhere.”
She was also optimistic about the change in attitude toward shoreline erosion along the Kahana coast. In Kahana there are nearly 1,000 units, mainly in nine different condominiums, all of them endangered by rising seas. The approach has gone from considering mitigation one parcel at a time to a more inclusive approach that takes the entire beach (known in scientific language as “beach littoral cell”) into account.
“In my work, I don’t see ‘climate deniers’ so much as ‘climate ignorers.’”
”Our community here on Maui is highly aware and a lot of what we’re doing is driven by the community itself,” said Owens. “We’re getting to the point where people understand that a parcel by parcel response isn’t going to work. When you’re talking about beaches you have to look at it from a systems perspective. Reefs and dunes are actually protecting the coastline. Storms would be worse if these buffers were not there to absorb the storm energy.”
“I consider that shift in perception a success,” she said. On the other hand, she finds it discouraging, “to make recommendations and find they are not implemented.”
“In my work,” she said, “I don’t see ‘climate deniers’ so much as ‘climate ignorers.’ They know about the impacts because they can see them, but they choose to either ignore the effect and/or defer action.”
“Sometimes,” she acknowledged, “there is not a ready solution. To find one takes the whole community and the whole state to address the issue. It’s a fact that a lot of existing development is threatened.”
This fact has elicited a variety of responses. Owens has heard that it’s become harder to insure shoreline property. Realtors have adopted stiffer language in the addendum used for the sale of shoreline property. But all laws requiring disclosure of information related to the probable impact of sea level rise were defeated in the most recent legislative session.
Owens, meanwhile, is supportive of the concept of “managed retreat.”
“That does not mean ‘cut and run,’” she said. “It means identifying, realigning, and – where feasible – relocating structures, roadways, and other man-made features that are threatened.”
Some ask, is the Hawai‘i Sea Level Rise Viewer reliable enough to influence these kinds of policy and hard money decisions?
“There are always limitations to data and models. Yet with the development and adoption of the Hawai‘i Sea Level Rise Report and Viewer, we are fortunate to have some of the best and highest resolution modeling that exists.”
Owens acknowledged there have been questions about the viewer’s projections.
“There is an adage that is used in the scientific world that ‘All models are wrong, but some models are useful.’ This is particularly relevant to this application,” she said. “There are always limitations to data and models. Yet with the development and adoption of the Hawai‘i Sea Level Rise Report and Viewer, we are fortunate to have some of the best and highest resolution modeling that exists.”
The models were developed by the University of Hawai‘i Coastal Geology Group led by Dr. Chip Fletcher, an eminent scientist at UH studying the impacts of climate change, Owens explained, and have been published in peer-reviewed academic literature.
“Further,” according to Owens, “the Sea Level Rise Report – a 300 page companion to the viewer and models included in the viewer – have been adopted by the State of Hawai‘i’s Climate Change Mitigation and Adaptation Commission.” The commission updated the report’s disclaimer to read (in part): “having gone through peer review and publication in the Nature Journal Scientific Reports, the results of this study are sufficiently validated to be appropriately used in land management decisions as the best available information as of the date of publication of the report, December 2017.”
“Given the information we have,” she asked, “do we get bogged down with a certain amount of imperfection, and then by default ignore the impacts that are already observed in our communities and worsening in the future?”
“Or do we adapt our policies to accommodate future conditions to the highest degree possible? What can we do now as an island community so that we won’t look back in 50 years and wonder why we didn’t make better choices?”
Tara Owens is available for consultation and presentations related to sea level rise. Call her at 808-463-3868 or email at [email protected] The companion report to the Hawaii Sea Level Rise Viewer is accessible by clicking here.
Cover design by Darris Hurst. Graphic design by Darris Hurst and Brittany Skiller.