Conceptual diagram of carbon reduction and removal technologies. Credit: Benedict S. Probst Carbon credits allow companies to offset their greenhouse gas emissions through mitigation projects in order to meet voluntary targets, compliance obligations, or national net-zero goals. However, a recent analysis found that at least 84% of carbon credits did not represent real emissions reductions. Avoided emissions claimed by protecting forests can be double-counted—or reversed if those trees are later harvested—and some mitigation, such as certain renewable energy projects, would likely have gone forward even without being counted as a credit. Publishing in PNAS Nexus , Benedict S. Probst and Florian Egli argue that permanent carbon removal , such as biochar, enhanced rock weathering, or direct air carbon capture and storage, should play an increasingly important role in reaching net-zero emissions.…