Forests are the nation’s largest terrestrial carbon sink, offsetting approximately 15% of carbon dioxide emitted in the U.S. each year. Grasslands, wetlands and coastal habitats also store significant amounts of carbon in soils, sediment and vegetation.
Optimizing that carbon storage will be critical to meeting climate goals, and, with the right financial incentives, can create a new source of rural income.
The Trillion Trees and National Carbon Storage Act, introduced by a bipartisan coalition of senators, would help the U.S. maximize carbon storage and measure impact. Climate scientists helped shape the bill, and it shows. Here are five important ways the bill gets it right.
1. The right target: National carbon stock objective
The act requires the Secretary of Agriculture, in consultation with the National Oceanic and Atmospheric Administration, to establish a domestic target for carbon sequestration in forest, grassland, wetland and coastal blue carbon ecosystems, across all types of land ownership.
The targets must be feasible and ecologically appropriate — namely, achievable within 10 years and reestablished every 10 years thereafter through 2100, designed to protect critical habitat and informed by local stakeholder input.
Shifting from an exclusive focus on timber harvest to net carbon stock targets means that forests and other ecosystems will be valued not just for the commercial price of harvested materials but also for climate mitigation functions. Optimizing for net carbon stock will also make apparent the importance of ecosystem conservation and restoration.
2. The right metric: Net carbon stock
Managing ecosystems in a changing climate requires the ability to identify where and how much carbon is currently present and make projections for the future. Selecting the appropriate metric to achieve this is critically important, and the Trillion Trees Act gets it right with “net carbon stock,” the amount of carbon stored in discrete portions of the biosphere at a given time.
Complex ecosystems like forests have many unique carbon pools, including live aboveground biomass, belowground biomass, deadwood, forest floor litter and soil carbon. In addition, harvested wood products in use and in landfills also contain carbon.
Net carbon stock accounts for all of these pools and how the amount of carbon they contain varies over time.
The amount of carbon stored varies over time and place. For example, young timber stands accumulate carbon while growing, and carbon in deadwood is released as wood decays. While living biomass like trees and the understory make up the majority of carbon in some eastern forests, soil typically accounts for the most carbon in coastal forests. Image credit: Congressional Research Service [PDF].
The U.S. Forest Service already tracks net carbon stock in forests and some grasslands. The Trillion Trees Act expands accounting and objective setting to also cover all grasslands, wetlands and coastal ecosystems.
Grasslands store about 8% of the U.S. terrestrial carbon, almost entirely in soil. Terrestrial wetlands store 22% of U.S. carbon, while also providing a variety of climate adaptation and resilience benefits.
Incorporating these ecosystems into the national net carbon stock objective could help lead to much needed conservation and restoration.
4. The right collaboration: Expertise for carbon accounting
The act directs the U.S. Forest Service to share expertise with states and recipients of foreign aid to help local foresters better understand the climate benefits of various ecosystems.
This includes sharing the technical capacity to help identify opportunities to increase carbon stored in urban forests, which provide multiple benefits for environmental quality and community well-being, including reducing the urban heat island effect and other stressors that disproportionately impact minority and economically disadvantaged communities. The Trillion Trees and Natural Carbon Storage Act would put the U.S. on a path to unlocking the full potential of the nature-based climate solutions provided by ecosystems, a major win for all Americans: Share on X
5. The right support: Expanded access to carbon markets and funding for reforestation
The bill’s Rural Forest Market Investment Program authorizes the Secretary of Agriculture to provide federal financing to support rural, private forest landowners This program would equalize access to carbon markets by boosting participation from “land-rich, cash-poor” foresters, and encourage credit aggregation where it’s necessary to make their participation in forest carbon markets financially viable.
The Trillion Trees Act provides new funding for reforestation, appropriating $10 million annually through 2025 to support Forest Service nurseries and reforestation efforts, and an additional $25 million annually to support state foresters. It also requires states to consider net carbon stock in forest planning. This funding is expected to help alleviate the nation’s 1.3-million-acre backlog of reforestation projects.
Nature itself is a powerful tool for reducing climate risk and increasing climate resilience. The Trillion Trees and Natural Carbon Storage Act puts the U.S. on a path to unlocking the full potential of the nature-based climate solutions provided by forests, grasslands, wetlands and coastal ecosystems.