Substantial cooling effect from aerosol-induced increase in tropical marine cloud cover

Chen, Y. ORCID: https://orcid.org/0000-0002-0319-4950, Haywood, J. ORCID: https://orcid.org/0000-0002-2143-6634, Wang, Y. ORCID: https://orcid.org/0000-0002-9480-3570, Malavelle, F., Jordan, G. ORCID: https://orcid.org/0000-0002-3129-4983, Peace, A., Partridge, D. G. ORCID: https://orcid.org/0000-0002-5970-901X, Cho, N. ORCID: https://orcid.org/0000-0001-6401-2391, Oreopoulos, L. ORCID: https://orcid.org/0000-0001-6061-6905, Grosvenor, D., Field, P., Allan, R. P. ORCID: https://orcid.org/0000-0003-0264-9447 and Lohmann, U. ORCID: https://orcid.org/0000-0001-8885-3785 (2024) Substantial cooling effect from aerosol-induced increase in tropical marine cloud cover. Nature Geoscience. ISSN 1752-0908 doi: 10.1038/s41561-024-01427-z

Abstract/Summary

With global warming currently standing at approximately +1.2 °C since pre-industrial times, climate change is a pressing global issue. Marine cloud brightening is one proposed method to tackle warming through injecting aerosols into marine clouds to enhance their reflectivity and thereby planetary albedo. However, because it is unclear how aerosols influence clouds, especially cloud cover, both climate projections and the effectiveness of marine cloud brightening remain uncertain. Here we use satellite observations of volcanic eruptions in Hawaii to quantify the aerosol fingerprint on tropical marine clouds. We observe a large enhancement in reflected sunlight, mainly due to an aerosol-induced increase in cloud cover. This observed strong negative aerosol forcing suggests that the current level of global warming is driven by a weaker net radiative forcing than previously thought, arising from the competing effects of greenhouse gases and aerosols. This implies a greater sensitivity of Earth’s climate to radiative forcing and therefore a larger warming response to both rising greenhouse gas concentrations and reductions in atmospheric aerosols due to air quality measures. However, our findings also indicate that mitigation of global warming via marine cloud brightening is plausible and is most effective in humid and stable conditions in the tropics where solar radiation is strong.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/116007
Identification Number/DOI	10.1038/s41561-024-01427-z
Refereed	Yes
Divisions	Interdisciplinary Research Centres (IDRCs) > Walker Institute Science > School of Mathematical, Physical and Computational Sciences > National Centre for Earth Observation (NCEO) Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Springer Nature
Download/View statistics	View download statistics for this item