’Ulu is one of the most climate-friendly, nutrient-dense foods you can put on your plate. That’s because of the unique, carbon-storing nature of breadfruit trees, especially when planted as part of diversified agroforestry. Pacific peoples have practiced this form of land management for millennia – practices which many today see as a ray of hope in the face of industrialized agriculture’s negative consequences, including climate change and soil degradation.
Agriculture and Greenhouse Gas Emissions
A 2018 study published in Science found that a quarter of global carbon emissions come from the food sector and most of these emissions come from the modern farming model itself – not from food distribution and transportation as one might think. Production of mass-consumed staples like rice, for instance, fill our atmosphere with greenhouse gases. The Environmental Defense Fund reports that rice grown in flooded conditions releases up to 12% of global methane emissions and, when grown in intermittently flooded conditions, also releases high levels of nitrous oxide, another powerful greenhouse gas. ‘Ulu trees are different because they capture carbon dioxide from the atmosphere while also supporting soil carbon sequestration.*
Breadfruit Stores Carbon Above Ground and Below
Above ground, an ‘ulu tree stores carbon in biomass like the bark, trunk, branches and fruit. But did you know that soil holds 80% of the total carbon of terrestrial ecosystems? That’s five times more carbon than is stored in plants and animals combined! Below ground, a breadfruit tree’s deep root systems support a robust soil ecosystem where complex interactions between fungi, bacteria and microfauna sequester carbon into the soil. Rather than deplete soil’s organic matter through deforestation, tilling, and erosion, ʻulu tree agroforestry improves soil health over time.
As we continue to convert fallow lands and cropland to breadfruit agroforests, more carbon is held in the soil—and also in delicious, nutritious breadfruit! Interested in ordering breadfruit? Check out our online store where we provide breadfruit and many other Hawai'i grown starches.
*The chart above was created with data provided by Our World in Data, using proxy figures to guesstimate carbon emissions from small-scale ʻulu production in Hawaiʻi.
Kritee, K. et al. (2018) “Global risk assessment of high nitrous oxide emissions from rice production” Environmental Defense Fund, New York.
Ontl, T. A. & Schulte, L. A. (2012) Soil Carbon Storage. Nature Education Knowledge 3(10):35
Ritchie, H., (2020). “You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local.” Our World In Data.