Alternative climate metrics to the Global Warming Potential are more suitable for assessing aviation non-CO₂ effects

Aviation's contribution to climate change extends beyond CO₂ emissions, with non-CO₂ effects now estimated to account for roughly two-thirds of aviation's total warming impact. This paper explores alternative climate metrics to the Global Warming Potential (GWP), focusing on their neutrality, temporal stability, compatibility with existing policies, and simplicity. Using the AirClim model, the study analyzes several metrics, including Radiative Forcing (RF), GWP, Global Temperature Change Potential (GTP), Integrated GTP (IGTP), Average Temperature Response (ATR), and efficacy-weighted variants. The findings suggest that the ATR and Efficacy-weighted GWP (EGWP) offer more accurate assessments of current and future aircraft using novel fuels, compared to the widely used GWP.

Liam Megill, Kathrin Deck, Volker Grewe