Westerly wind shifts drove Southern Hemisphere mid-latitude peat growth since the last glacial

Thomas, Zoë A.; Cadd, Haidee; Turney, Chris; Becerra-Valdivia, Lorena; Haines, Heather A.; Marjo, Chris; Fogwill, Christopher; Carter, Stefanie; Brickle, Paul

Westerly wind shifts drove Southern Hemisphere mid-latitude peat growth since the last glacial

Thomas, Zoë A. ORCID: https://orcid.org/0000-0002-2323-4366; Cadd, Haidee; Turney, Chris; Becerra-Valdivia, Lorena ORCID: https://orcid.org/0000-0001-5501-5347; Haines, Heather A. ORCID: https://orcid.org/0000-0003-0019-4151; Marjo, Chris ORCID: https://orcid.org/0000-0003-0549-0363; Fogwill, Christopher ORCID: https://orcid.org/0000-0002-6471-1106; Carter, Stefanie ORCID: https://orcid.org/0000-0001-7713-876X; Brickle, Paul. 2025 Westerly wind shifts drove Southern Hemisphere mid-latitude peat growth since the last glacial. Nature Geoscience. 9, pp. 10.1038/s41561-025-01842-w

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Official URL: https://doi.org/10.1038/s41561-025-01842-w

Abstract/Summary

Extratropical peatlands in the Southern Hemisphere preserve detailed information on climatic and environmental change going back millennia. They are particularly valuable for understanding the evolution of the mid-latitude southern westerly winds (SWW), which play a major role in driving regional temperature and precipitation patterns, Antarctic sea-ice extent and ocean carbon fluxes. Here we investigate the timing and drivers of peatland initiation across the southern mid-latitudes after the Last Glacial Maximum (21,000 years ago) and test how this might relate to past changes in the SWW. We radiocarbon-date basal peats from the Falkland Islands and collate published basal peat radiocarbon ages from peat-forming regions south of 35° S. Using kernel density estimate models, we find distinct latitudinal phases of post-glacial peat initiation that suggest that peat growth is sensitive to variations in SWW position through their influence on moisture availability, temperature and dust deposition. A peak in peat growth in regions north of 52.5° S during the Antarctic Cold Reversal (14,700–12,800 years ago) suggests an equatorward migration of the SWW, coinciding with a slowdown in atmospheric CO 2 increases. In light of recent SWW intensification and poleward migration, our findings highlight the potential for ongoing changes in the Southern Hemisphere climate and carbon fluxes under continued anthropogenic heating.

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1038/s41561-025-01842-w

UKCEH and CEH Sections/Science Areas:

Environmental Pressures and Responses (2025-)

ISSN:

1752-0894

Additional Information:

Open Access paper - full text available via Official URL link.

Additional Keywords:

climate sciences, palaeoclimate