Land is a critical component of the climate system, actively engaged in the flows of carbon, nitrogen, water, and oxygen—essential building blocks for life. Carbon is the core of trees and grasses, mammals and birds, lichens and microbes. Linking one atom to the next, and to other elements, it’s the fundamental material of all living organisms. Plants and healthy ecosystems have an unparalleled capacity to absorb carbon through photosynthesis and store it in living biomass. In addition, soils are, in large part, organic matter—once-living organisms, now decomposing—making them an enormous storehouse of carbon. Land can therefore be a powerful carbon sink, returning atmospheric carbon to living vegetation and soils. While the majority of heat-trapping emissions remain in the atmosphere, land sinks currently return 26% of human-caused emissions to earth—literally.
NOTE: Land sinks absorb roughly 29% of the carbon dioxide emissions pumped into the atmosphere each year. When we consider other greenhouse gases, including methane, nitrous oxide, and fluorinated gases, land absorbs approximately 26% of the total emissions. (Global Carbon Project analysis adjusted to include all greenhouse gases at 100 year global warming potential.)
Human activity can disrupt land-based sinks through agriculture, forestry, and related practices. The unfolding impacts of climate change, including increased drought, fire, ice melt, and disease, may further threaten their integrity. But human activity can also help reverse this course, by actively supporting terrestrial carbon uptake and storage—especially in forests, wetlands, and agricultural lands
How can we help sequester more carbon in biomass and soil? What can we do to support and enhance natural processes, including the capacity of land to renew? These questions matter not only for emissions but for a diversity of human needs—and for maintaining a healthy diversity of flora and fauna. Because soil with more carbon content can also be more productive and resilient, these questions are critical for building a thriving food system too.
Climate solutions that enhance land-based sinks cluster around waste and diets, ecosystem protection and restoration, improved agriculture practices, and prudent use of degraded land.
- Address Waste and Diets. Reducing food waste and shifting to plant-rich diets are two critical interventions to prevent deforestation. Lower demand for food and farmland spares nature from additional clearing, indirectly protecting carbon sinks.
- Protect and Restore Ecosystems. “Let nature be nature” is a powerful principle—let peatlands, grasslands, and forests continue to do what they do best by protecting them from human disturbance. Where ecosystems have been degraded, restoration can help them recuperate form and function, including absorbing and storing more carbon over time.
- Shift Agriculture Practices. What and how we grow, graze, or harvest can be a means to cultivate biomass and regenerate soil carbon. An array of “regenerative agriculture” methods are being rediscovered and developed worldwide, and show promising results. The integration of trees into farming through agroforestry practices is particularly powerful. All solutions that sustainably raise yields on existing farmland can also reduce the pressure to clear other areas.
- Use Degraded Land. Lastly, degraded lands can be put to use in ways that revive productivity, increase biomass, promote soil carbon sequestration—all while producing wood, fiber, or food.
There is significant overlap in the solutions that stop land-based sources of greenhouse emissions and those that support land-based carbon sinks. Their unique power is doing both at the same time. All of them are critical to coming back into balance with the planet’s living systems.