Satellite-Based Quantification of Contrail Radiative Forcing over Europe: A Two-Week Analysis of Aviation-Induced Climate Effects

TL;DR

This study uses satellite imagery over two weeks to quantify the radiative forcing of aviation-induced contrails over Europe, revealing their net warming effect, especially at night, and a significant increase in contrail coverage and warming from 2023 to 2024.

Contribution

It provides the first satellite-based quantification of contrail radiative forcing over Europe and highlights the importance of temporal factors in assessing their climate impact.

Findings

Daytime contrails have a cooling effect, nighttime contrails cause net warming.

Contrail radiative forcing increased by 128.7% from 2023 to 2024.

Contrail coverage increased by 41.03% over the studied period.

Abstract

Aviation's non-CO$_2$ effects, especially the impact of aviation-induced contrails, drive atmospheric changes and can influence climate dynamics. Although contrails are believed to contribute to global warming through their net warming effect, uncertainties persist due to the challenges in accurately measuring their radiative impacts. This study aims to address this knowledge gap by investigating the relationship between aviation-induced contrails, as observed in Meteosat Second Generation (MSG) satellite imagery, and their impact on radiative forcing (RF) over a two-week study. Results show that while daytime contrails generally have a cooling effect, the higher number of nighttime contrails results in a net warming effect over the entire day. Net RF values for detected contrails range approximately from -8 TW to 2.5 TW during the day and from 0 to 6 TW at night. Our findings also show a 41.03% increase in contrail coverage from January 24-30, 2023, to the same week in 2024, accompanied by a 128.7% rise in contrail radiative forcing (CRF), indicating greater warming from the added contrails. These findings highlight the necessity of considering temporal factors, such as the timing and duration of contrail formation, when assessing their overall warming impact. They also indicate a potential increase in contrail-induced warming from 2023 to 2024, attributable to the rise in contrail coverage. Further investigation into these trends is crucial for the development of effective mitigation strategies.