Sartzetakis et al. (2025): Evaluating Temporal Trade-Offs in Climate Effects from Carbon Dioxide Removal Strategies Across Different Metrics: A Case Study on Wetland Restoration
Stavroula Stephane Sartzetakis, Tianyi Sun, Yangyang Xu, Emily Ury, Ilissa Bonnie 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. The authors 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.