Opportunities, Priorities, and Leverage Points for Protecting Irrecoverable Carbon Areas in the U.S.

Abstract

A focus on carbon storage as one benefit of land conservation has grown in recent years due to a greater appreciation of the role of nature-based climate solutions to mitigate climate change. Conservation NGOs are emphasizing carbon conservation as a goal, governments are creating carbon-focused land management policies, and businesses focused on “carbon credits” are expanding.1, 2 3 But, which carbon is the most valuable and vulnerable? With so many threatened areas, which should be chosen as the most important to protect? First introduced in 2020 and mapped in 2021, irrecoverable carbon provides a framework for prioritizing conservation efforts.4 Irrecoverable carbon (IRC) describes dense stores of above- and below-ground carbon, sequestered in biomass and soil over decades to millennia, that are vulnerable to release into the atmosphere by human activities. If released, this carbon will not be restored or naturally re-sequestered by 2050, the point at which the world must reach net-zero emissions to avoid the worst consequences of climate change.5 It is commonly measured in megagrammes (Mg), with Mg per hectare or acre used for density. In this report, you will also find IRC measured in megatonnes (Mt), where 1 million Mt is equal to 1 Mg. In this report, we provide an overview of IRC areas within the United States and a characterization of the primary threats to and possible pathways to protection for high carbon areas. We present case studies from across the United States to inform landscape prioritization and management by NGOs, federal and state agencies, and policymakers.