University of Southampton Research Shows Southern Westerly Winds Drove Massive Peat Growth and Altered Global Carbon Cycling 15,000 Years Ago

IMAGE Ancient bogs Hemisphere hold clues to a major shift in the Earth’s climate after last Ice Age

(IN BRIEF) A global team led by the University of Southampton has discovered that ancient peat bogs across the Southern Hemisphere expanded rapidly around 15,000 years ago due to abrupt shifts in the Southern Westerly Winds, a finding published in Nature Geoscience. By radiocarbon-dating peat from regions including South America, Australasia, southern Africa, and sub-Antarctic islands, the researchers identified a consistent link between wind migration and the wet conditions necessary for long-term bog development. The study shows that the winds not only influenced peat formation but also affected how much carbon the Southern Ocean absorbed—an important factor in global climate regulation. With modern observations indicating that the winds are now shifting toward the South Pole due to climate change, the scientists warn that the planet’s largest natural carbon sink is at risk of weakening, a trend already tied to increased droughts and wildfires. The findings underscore the interconnected nature of atmospheric circulation, ocean carbon uptake, and terrestrial carbon storage, offering new insight into both past and future climate dynamics.

(PRESS RELEASE) SOUTHAMPTON, 19-Nov-2025 — /EuropaWire/ — Scientists from the University of Southampton and an international network of collaborators have uncovered new evidence that ancient peat bogs across the Southern Hemisphere were shaped by dramatic shifts in global wind patterns thousands of years ago. The team’s research shows that abrupt movements of the Southern Westerly Winds around 15,000 years ago created ideal wet conditions that sparked rapid expansion of peatlands—vast natural carbon stores that play a central role in regulating the planet’s climate.

For decades, geoscientists have debated why widespread bog systems appeared so suddenly after the last Ice Age. The new study, published in Nature Geoscience, now points to shifting wind belts as a decisive factor influencing the growth and distribution of these carbon-rich landscapes. Led by the University of Southampton, the project brought together experts spanning South America, Australasia, southern Africa, and the sub-Antarctic islands.

According to lead author Dr Zoë Thomas of the University of Southampton, the position of the Southern Westerly Winds exerts far-reaching influence on both peatland carbon storage and the exchange of carbon dioxide between the atmosphere and the ocean. “When the winds shifted north 15,000 years ago, they changed the stirring action of the Southern Ocean,” she said. “This region acts as the Earth’s largest natural carbon sink, so any change in these winds can have major implications for the global carbon cycle.”

Dr Thomas, pictured above in a Falklands bog

Peatlands form over millennia as waterlogged soils accumulate layers of partially decomposed plants. By radiocarbon-dating peat samples taken from multiple continents, the researchers were able to pinpoint exactly when climatic conditions became sufficiently cool, wet, and stable to support long-term bog formation. The analysis revealed a striking pattern: major phases of peat growth aligned closely with periods when the winds migrated north or south—movements that also coincided with fluctuations in atmospheric CO₂.

The findings carry significant weight for today’s changing climate. Recent observations show the Southern Westerly Winds shifting toward the South Pole, a trend linked to rising greenhouse-gas concentrations. Dr Thomas warns that this shift could undermine the Southern Ocean’s ability to absorb carbon, potentially disrupting one of Earth’s most vital natural buffers against climate change. “This southerly movement has already contributed to worsening droughts and wildfires across southern continents,” she noted.

Co-author Dr Haidee Cadd from the University of Wollongong in Australia emphasized that weakening the planet’s largest natural carbon sink could accelerate CO₂ buildup and intensify global warming. The study’s authors say their findings highlight the delicate balance between atmospheric circulation, ocean carbon uptake, and the long-term health of the world’s peatlands.

The full research article is available at doi.org/10.1038/s41561-025-01842-w.

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SOURCE: University of Southampton