Hawaiʻi’s goal of achieving carbon neutrality by 2045 has a team of local and Native Hawaiian researchers cultivating solutions. They mapped unmanaged, fallow agricultural land around the state and found that if all the land was converted into agroforests, it would counteract the carbon emissions of 100 million barrels of oil.
Agroforestry incorporates trees and shrubs into food production. Leah Bremer and Kawika Winter spoke with The Conversation about their group's research and emphasized the importance of community-based, culturally relevant agroforestry for sustainable land management and carbon sequestration.
Interview Highlights
On agroforestry restoration and carbon neutrality
LEAH BREMER: What does it mean if we think about agroforestry scaled up, for a lack of better words, particularly on fallow agricultural lands? So we know that about 40% of our agricultural lands are fallow or unmanaged — as we've seen in the recent fires, pose high fire risk, also do not provide a lot of value. So we wanted to look at the benefits of scaling up the restoration… We're looking at lots of different benefits of agroforestry, but our focus on carbon for this paper is kind of multiple reasons. One, climate change, right, but then also related to that Hawaiʻi has committed to carbon neutrality by 2045, right. And of course, the biggest part of that is reducing fossil fuel use. But we can't get to neutrality if we don't also think about the role of land care and management and helping to reach that goal.
On utilizing Indigenous knowledge
KAWIKA WINTER: I think the ultimate origins of this paper, at least for me, is this bigger question, how is the human civilization going to survive on this planet in the future? How are we going to feed 9 billion people, or however many people on the planet right now? How are we going to keep having a stable climate while providing our energy? And the answer to a lot of these questions are to look back at Indigenous knowledge, because there have been Indigenous-formed eco-civilizations on this planet that figured out how to support high populations while keeping forests, while feeding their people, while keeping the integrity of the oceans and all these things. Turns out that we're living in this beautiful place of Hawaiʻi that was once home to one of those amazing eco-civilizations. So there was, at that time, there were zero food imports, so we were feeding more than a million people in these islands without importing food. We were able to do that while maintaining our forests. And so this is the, one of the things that I think about, really what's gonna make it or break it for humanity, is figuring out how to maintain the forests of the planet.
On what the results show
BREMER: What we came up with was about 370,000 acres of land that you could potentially transition to these, what we're calling these multistrata agroforestry systems… That's about half of the unmanaged agricultural land, right. So that's a big part of land. It's about 10% of the state. And then we also found about 25,000 acres of that non-native dominated conservation mass. We then looked at, OK, how much carbon in the vegetation could these systems sequester? And we find the number between 90 and 125 metric tons of carbon per hectare. So that's a number that probably doesn't mean a whole lot to too many people, but it's, you know, about the same as native forest. So we're not in any way suggesting to do agroforestry instead of native forests. It's just, it's a hybrid restoration system that has a history here and is culturally relevant here that makes a lot of sense on many parts of of Hawaiʻi. And then the last piece is we wanted to include soil carbon, right. Because that's a huge part of the carbon story, but often left out in some of these carbon-offset projects, because it's hard to figure out what happens to soil carbon. And what we find is there's the most evidence for an increase in soil carbon if you're transitioning areas that were used for intensive cultivation. So it's the areas that were in pineapple and sugar plantations that we actually have the most potential to increase soil carbon and above-ground carbon at the same time. If there's people who want to fund community-based, place-based, ʻōiwi-led agroforestry, and they want also to support carbon — those areas are kind of your hotspots.
On how transitioning lands would benefit the collective
BREMER: The message I would want people to take from this work is that, as a state, we need to figure out how to transition these lands, right. There's no option. We can't just keep 20% of the state in non-native grasses and non-native shrublands that pose huge fire risks and don't produce food on land that's zoned agriculture, right. We have different options of how to transition them. Agroforestry is one of them, and the more we can recognize the benefits that those stewards provide to all of us, and translate our recognition of those benefits into support for the people that are taking care of these lands, I think that's where we can get to a much, you know, more sustainable and resilient society.
This interview aired on The Conversation on Feb. 26, 2025. The Conversation airs weekdays at 11 a.m.
