Every day, human scientists invent new technologies to address climate change. These innovative developments are exciting, but some of the best climate solutions have existed for thousands of years. Have you heard of breadfruit or the mycorrhizal fungus that can pull carbon out of the atmosphere? The natural world is full to the brim with fascinating ways of rebalancing our climate, and in looking for answers, we can turn to the Earth itself for guidance.
Take mangrove forests, for example, which are known for their complex root structures. These trees grow along sheltered tropical coasts across the globe, and those trademark tangled roots are the key to powerful carbon sequestration. Mangroves can pull carbon out of the air and store it up to ten meters down in their waterlogged soil, allowing them to hold up to five times more carbon than tropical forests.
Around the world, organizations and governments are recognizing the potential of mangroves to help reduce the impact of greenhouse gas emissions. Deforestation is a major issue that these trees face, and in the last 70 years, scientists estimate that up to 50% of the world’s mangroves have been lost. This comes primarily from an increase in agriculture, which is necessary to feed the growing global population, though can be done in ways that maintain rich carbon sink ecosystems. For this reason, UNESCO declared July 26 to be World Mangrove Day in order to raise awareness, and conservation groups around the world like the Mangrove Action Project are working to prevent further loss of these powerful trees.
The agriculture sector is one of the biggest producers of greenhouse gasses, but farmers are finding ways to offset carbon emissions by sequestering it in soil. One example is fungi, which often form symbiotic relationships with the roots of the plants they grow on. There’s a type of mushroom that can do even more: the mycorrhizal fungus actually pulls carbon out of the atmosphere to boost the growth of its symbiotic plant partner. In Australia, farmers have been at the forefront of research to develop a method of mixing mycorrhizal spores with fertilizer to maximize the fungus’ carbon sequestration powers. Through responsible, regenerative practices, farmers can take the power to reverse the effects of global warming into their own hands and make change from the ground up—literally.
Along the coast of every continent except Antarctica grows another carbon sink superpower: seagrass. Though only covering about 0.2% of the ocean floor, it sequesters more than 10% of carbon in the sea. This means that per hectare, it can store double the carbon of the average forest on land. Seagrass however is incredibly sensitive to rising temperatures, and in places like the United Kingdom, nearly 90% of seagrass meadows have suffered because of warming waters and industrial activity. The process of restoring seagrass is a very difficult one, but payoffs are more than worth it. Just one in ten hand-planted seagrass plants survives to maturity, but community-led revitalization of underwater meadows not only act as efficient carbon sinks, but also help boost marine life and biodiversity by providing a habitat for native species.
Not all carbon-sequestering plants have growth rates as low as seagrass, however. Stands of bamboo shoots can grow up to ten feet in a single year, and in that time, store six times the carbon of an average forest of similar size! While the sequestration efficiency of bamboo dips below competitors after a century or two, it can quickly seal away enormous amounts of carbon. Bamboo also has the power to filter dust and dangerous particles out of the air in places like California, where drought and wind storms combine to cause health problems like asthma. It can help balance extreme temperatures by providing shade, and act as a sustainable building material, as it is very strong, fast-growing, and resilient to withstand a wide variety of conditions.
Breadfruit, or ‘ulu, is another multi-talented carbon sink. The trees on which it grows are long-lived, holding carbon for generations while continuing to produce nutritious fruit. Full of carbohydrates, breadfruit has been a staple crop in Polynesia for centuries, and offers a sustainable gluten-free flour. As demand for ecologically-friendly food systems rises, breadfruit offers a potential solution to the growing problem of food insecurity. It is a traditional component in agroforestry, a farming technique that mixes many crops on the same plot of land to increase agricultural biodiversity and make the most of available land.
From mangroves and seagrass all the way to bamboo, natural carbon sinks are everywhere. As we continue searching for the keys to clearing our atmosphere of greenhouse gas emissions, let’s turn our eyes to nature’s ancient solutions to increasing our carbon stocks.