Has reducing ship emissions brought forward global warming?
Author(s)
Type
Journal Article
Abstract
Ships brighten low marine clouds from emissions of sulfur and aerosols, resulting in visible “ship tracks”. In 2020, new shipping regulations mandated an ∼80% reduction in the allowed fuel sulfur content. Recent observations indicate that visible ship tracks have decreased. Model simulations indicate that since 2020 shipping regulations have induced a net radiative forcing of +0.12 Wm−2. Analysis of recent temperature anomalies indicates Northern Hemisphere surface temperature anomalies in 2022–2023 are correlated with observed cloud radiative forcing and the cloud radiative forcing is spatially correlated with the simulated radiative forcing from the 2020 shipping emission changes. Shipping emissions changes could be accelerating global warming. To better constrain these estimates, better access to ship position data and understanding of ship aerosol emissions are needed. Understanding the risks and benefits of emissions reductions and the difficultly in robust attribution highlights the large uncertainty in attributing proposed deliberate climate intervention.
Date Issued
2024-08-16
Date Acceptance
2024-05-24
Citation
Geophysical Research Letters, 2024, 51 (15)
ISSN
0094-8276
Publisher
Wiley Open Access
Journal / Book Title
Geophysical Research Letters
Volume
51
Issue
15
Copyright Statement
© 2024 Battelle Memorial Institute and The Author(s).
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Identifier
http://dx.doi.org/10.1029/2024gl109077
Publication Status
Published
Article Number
e2024GL109077
Date Publish Online
2024-08-12