Sartzetakis et al. (2025): Temporal trade-offs in climate benefits from carbon dioxide removal—insights from wetland restoration and assessment metrics
Stavroula S. Sartzetakis, Tianyi Sun, Yangyang Xu, Emily A. Ury, Ilissa B. Ocko and Brian Buma, IN: Environmental Research Letters, https://doi.org/10.1088/1748-9326/adeb9d
CDR measures may unintentionally increase emissions of other climate forcers. If emissions of potent short-lived climate forcers (like methane) are increased, the CDR mechanism could potentially worsen climate change in the near-term despite benefiting the climate in the long-term. This temporal trade-off can be easily overlooked when employing the standard climate metric used for assessments—carbon dioxide equivalent (CO₂e) using a 100 year global warming potential (GWP)—because it solely conveys the long-term warming impacts of a pulse of emissions. A more sophisticated assessment method is needed to reveal potential temporal trade-offs in climate benefits—important information for effective decision making. In this study, the authors compare three climate impact assessment approaches of increasing complexity to evaluate temporal trade-offs in climate benefits from CDR strategies: (1) the standard CO₂e using GWP approach with both 20 and 100 year time horizons (GWP20 and GWP100, respectively, or dual-valued CO₂e); (2) a variation of GWP that considers the climate impact of continuous emissions over time (known as technology warming potential (TWP)); and (3) reduced complexity climate models. They use wetland restoration as a case study because studies have shown that it may remove carbon dioxide from the atmosphere, while also increasing methane emissions.