Understanding the Radiative Impact of Contrail Cirrus
- VIRGINIA VILLAPLANA FERNANDEZ
- 3 days ago
- 2 min read
Contrail cirrus clouds—the high-altitude ice clouds that form from aircraft exhaust—have long been recognized as contributors to aviation’s climate impact. However, quantifying their exact influence on Earth’s energy balance remains a complex challenge. In a recent E-CONTRAIL study, we present a new approach to estimate the radiative forcing of contrail cirrus using satellite observations and radiative transfer calculations.
The study focused on six specific days when contrail formation was evident over different parts of Europe. By leveraging satellite data and simulating atmospheric radiation, we were able to estimate the radiative impact of these clouds under real-world conditions.
Dimitropoulou, E., de Buyl, P., and Clerbaux, N.: Satellite-based estimation of contrail cirrus cloud radiative forcing derived through a Rapid Contrail-RF Estimation Approach, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-697, 2025.
Key Findings
One of the most intriguing results of our analysis is the dual nature of contrail cirrus’ radiative effects:
Warming occurs primarily at night and during winter, when contrails trap outgoing longwave radiation emitted by the Earth.
Cooling is more common during the daytime and in summer, as the ice particles in contrails reflect incoming solar radiation back into space.
This variability highlights the importance of context—both in terms of time of day and season—when assessing the climate effects of contrails.
To ensure the reliability of our method, we compared our estimates with other established approaches and datasets. These comparisons showed strong agreement, confirming that our observation-based method can provide accurate and meaningful estimates of contrail radiative forcing.
Aviation continues to grow globally, and with it, the environmental implications of air traffic. While CO₂ emissions are widely studied, the role of contrails and other non-CO₂ effects is often less well understood. The E-CONTRAIL findings contribute to a more comprehensive understanding of aviation’s full climate footprint and can help guide strategies for more sustainable air travel in the future.