Climate change is increasing hurricane risk for Hawaiʻi

Hawaiʻi has generally been safe from the worst effects of hurricanes. But this year two hurricanes battered the islands in a matter of weeks.

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• 0:00Speaker 00

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• 0:17Flora Lichtman?

  Hey, it's Flora, and you're listening to Science Friday. The Hawaiian islands tend to be insulated from the worst effects from hurricanes. But this summer told a different story. In mid-August, Hurricane Lala struck the big island, damaging homes and roads, creating flooding and power outages. Then, a few weeks later, Hurricane Lowell hit the islands of Nihihau and Kauai, leaving more destruction in its wake. So what do scientists make of this dramatic storm season for the Hawaiian islands? Joining me now is Dr. Hawnani Kanne, an assistant professor at the University of Hawaii at Manoa, where she studies how climate change impacts islands, reefs, and island people.

• 1:01Flora Lichtman?

  Welcome to Science Friday.

• 1:03Speaker 02

  Aloha, Flora, mahalo for having me here today.

• 1:06Flora Lichtman?

  Thank you so much for being here. How anomalous is this hurricane season for Hawaii?

• 1:12Speaker 02

  This hurricane season has been wild. The fact that, within a month, we had two back-to-back hurricanes, that is definitely something that I have not experienced in my lifetime.

• 1:26Flora Lichtman?

  I mean, do hurricanes usually make landfall in Hawaii?

• 1:29Speaker 02

  It's rare. It's rare for hurricanes to make landfall in Hawaii. A lot of times, as you have mentioned, we're buffered from the majority of the storms, due to both our isolated location, but also the fact that a lot of these hurricanes, they enter cooler waters before they come close to Hawaii. So with this year, with El Niño, with the prolonged warming of our oceans, the fact that our ocean is actually warmer and that there are numerous hurricanes that are coming straight for Hawaii, it's been, frankly, it's been a bit scary for a lot of the people that live here in Hawaii.

• 2:13Flora Lichtman?

  Is that how it feels for you?

• 2:16Speaker 02

  Yeah, I think so. I live in Hilo, on the big island, or Hawaii island. We're used to getting a lot of rain. We're used to getting wind. But this much rain, like upwards of 10, 15 inches over the course of a day or two, that it's been a lot.

• 2:39Flora Lichtman?

  So just to unpack it a little bit, we have an El Niño year, and you mentioned that the waters are getting warmer. And is the problem that then the hurricane doesn't lose power? Like, if it's not bumping into colder waters, it sort of stays powerful?

• 2:55Speaker 02

  Yeah, so when you look at typically what happens during El Niño, and also what is forecasted with climate change, you see that with an El Niño year, the waters are warmer, so that's more fuel for the hurricane. The warmer water season is prolonged with El Niño through the fall. And then the fact with climate change, it's projected that this warmer water and these warmer air temperatures will also steer the hurricanes further towards the west and towards the north. So it'll allow those tracks to come closer to Hawaii as well.

• 3:31Flora Lichtman?

  I mean, I think on the news, we've seen damage to houses and infrastructure. How are these storms impacting natural features like reefs and shorelines?

• 3:41Speaker 02

  Yeah, so we're still, we're still learning. We're still studying. We're still trying to figure out exactly how these storms have directly impacted our reefs. We've seen photos from reefs along the south shore of Maui that have been damaged. We've seen beaches that are covered in coral rubble. And this reminds me of a hurricane that came to Hawaii in 2018, Hurricane Walaka. And it was the first time in recorded history that this hurricane, a category-three hurricane, made direct landfall on one of the northern atolls in Papahana Mokuakia, National Marine Sanctuary. And what we saw there is these large, beautiful, pristine reefs

• 4:23Speaker 02

  with large-plated corals be completely, completely ripped off of the reef platform. And instead, you, you saw after the hurricane, large fields of rubble and sand. What we saw also was that entire islands were completely moved or swept off into the lagoon. And over the past eight years, we've been studying the recovery of these reefs. So I'm trying to understand, as a reef recovers, what are the first things that pop up? What are the first types of corals? What are the first types of algae? And then, how that then translates into the recovery of the islands?

• 5:06Speaker 02

  And, you know, seeing those cascading effects throughout the ecosystem. So using that as a lesson here for our main Hawaiian islands, we do understand that our reefs, you know, they're important. They not only help to dissipate the energy of these storms, the wave energy that comes to shore and eventually erodes our beaches, but they are also capable of recovery, and they are resilient as well. So a lot of our work has been focusing on trying to understand the direct impacts to the reefs, and then how that translates to land, so they can continue to protect our islands and our people well into the future.

• 5:49Flora Lichtman?

  Yeah, talk to me about that connection, the protection of the islands and how that's related to the protection of people.

• 5:55Speaker 02

  Yeah, so you know, from an islander's perspective, from a Hawaiian perspective, we're all related. There's no separation between people, place, or nature. We have an "olalono'ao" or a Hawaii saying in Hawaiian that says, "Hei pukua akani aina." And it can be translated in a number of ways. Literally, it's translated into a coral reef that grows into an island. So this is a little, you know, reverse of what we think of from like the geological evolution of islands where the reefs come later. But from this perspective, when we think especially about our sandy beaches and our older islands, it's the reefs that are literally feeding our islands with sediment.

• 6:39Speaker 02

  It's the reefs that are the platform upon which these atoll islands sit upon. And then it's the reef that is also literally, like, physically feeding our people with resources and cultural empowerment. We also believe that the first living organism was a coral polyp. And from the coral polyp, all other life, including humans, people, came from that coral polyp. So there's this really intimate relationship between, between our reefs and our people.

• 7:14Flora Lichtman?

  It's interesting, I hear you integrating all of these different types of knowledge, like in real time, in that answer, traditional knowledge, traditional science. How do you think about bridging these different ways of knowing?

• 7:28Speaker 02

  Yeah, I think of it as a, as a way of necessity. So living on islands, we see firsthand the impacts that climate change is having upon us, whether or not it's, you know, being warmer or having increased sea level rise, increased coastal erosion, drought resulting in wildfires. These are things that are affecting us now. It's not something that we're thinking about planning in the next 10, 15, 20 years. I've been a professor only a handful of years. And within that time, I've seen my students be directly, directly impacted by the wildfires on the haina. I've seen my students trying to complete their theses,

• 8:13Speaker 02

  but also having no electricity or internet or losing, you know, parts of their houses or caring for their families while there's also a hurricane that's impacting them. So for us here in Hawaii and for many other people that are living on islands, this is definitely, we see, we see the impacts of climate change, and we see them happening now. And we're trying our best, using all of the best available knowledge, whether or not it be something that's been passed down from generations or things that, you know, we're learning now by using technology to study what's happening around us.

• 8:52Flora Lichtman?

  Do the stakes feel very high?

• 8:55Speaker 02

  Oh, the stakes are higher than ever. And, you know, especially, especially, I think, being like a young professor and still considering myself as a student and having a young family, I'm thinking about how these things are going to, are impacting us not just now, but how they're going to impact our children and our children's children and our students and their children and all the future generations.

• 9:23Flora Lichtman?

  What's the knowledge we need?

• 9:25Speaker 02

  I think the knowledge that we need is to be open-minded. I think we need to be open-minded about where we're seeking knowledge, whether or not it be from our climate models, from, you know, our sensors that are out in the ocean, or if it's from the people that are living in the places that are being impacted the most. And I think we really need to consider what the needs are and the wants of those people and how they want to adapt. And we need to fight for, for those wants and those desires and making sure that that knowledge is helping us to develop solutions.

• 10:07Flora Lichtman?

  And what about science-wise? What are you researching now?

• 10:11Speaker 02

  Yeah, so science-wise, we're focusing a lot on resilience, natural resilience and thresholds of resilience, using both modern records, historical records, and paleo records. So trying to understand at what ranges of sea level rise or, you know, if we can identify storms in the past, how, how did our reefs, how did our islands fare during those time periods? And if we project those same values of sea level rise into the future, we'll get some sort of understanding of whether or not our reefs and our islands can continue to provide the same functions that we need them to as people.

• 10:54Flora Lichtman?

  What makes islands resilient? And can we use that knowledge to intervene in a helpful way to make the Hawaiian islands more resilient to climate change?

• 11:04Speaker 02

  Yeah, for sure. So I think there's definitely certain types of coral, certain types of limu or calcareous seaweeds that are more resilient than others. We're seeing that crustose coralline algae, that pink limu or seaweed that you find on rocks and corals is being, is really critical, both to the recovery of our reefs as well as the recovery of our beaches and our coastal areas. And then the other component is resilient islands are a lot of times a function of resilient people. So people and communities that understand the value of their resources,

• 11:47Speaker 02

  caring for their resources, and understanding their relationship with their place and with nature.

• 11:56Flora Lichtman?

  Dr. Hawnani Kanne is an assistant professor at the University of Hawaii at Manoa. Thank you so much for joining me today.

• 12:03Speaker 02

  Thank you so much for having me and for sharing this story. It's very important.

• 12:17Flora Lichtman?

  This episode was produced by Rasha Aridi, and I want to shout out Babs Gigi, who wrote on Apple Podcasts, "Each daily segment opens up a whole new world." I feel the same way. Thank you for that review, appreciate it. We will catch you next time. Thank you for listening. I'm Flora Lichtman.