Hi all, a few of us were discussing this recent paper at the UPTAKE meeting, some sober findings about offsets for things like nature based solutions but also our ongoing discussions about durability and permanence of storage. Link below, but PDF attached for convenience.

https://www.annualreviews.org/content/journals/10.1146/annurev-environ-112823-064813

This article provides a systematic review of the literature on carbon offsets. A growing number of studies have found that the most widely used offset programs continue to greatly overestimate their probable climate impact often by a factor of five to ten or more. Credit quality has remained a problem since the inception of carbon credits, despite repeated efforts to address the core challenges of additionality, leakage, double counting, environmental injustice, verification, and permanence. Combined, these issues have led many to conclude that overcrediting in carbon offsets is an intractable problem. These challenges helped stall the rapid growth in the voluntary carbon market (VCM) earlier this decade. They warrant renewed focus in the wake of COP29, where 200 nations significantly advanced the effort begun with the Paris Agreement to create the rules governing a global compliance market for carbon credits. But COP29 did not substantially address the quality problem, creating the risk the Paris compliance market will be rife with overcrediting and other problems—and that the VCM could undermine the Paris market. We recommend that all stakeholders begin focusing on high-integrity, durable carbon dioxide removal and storage, while recognizing that the recent literature has raised the question of whether durable means 100 years, 1,000 years, or longer. Ultimately, we find that many of the most popular offset project types feature intractable quality problems. We should focus on creating rules to find and fund the relatively few types of high-quality projects while employing alternative finance and strategies such as contribution claims for the critical projects in conservation, renewable energy, and sustainable development.