For decades, the ozone hole has disrupted the winds and currents of the Southern Ocean, weakening one of Earth’s most powerful carbon sinks. But new research offers hope: if greenhouse gas emissions are reduced, the ocean may regain its strength in absorbing atmospheric carbon—reinforcing the critical link between ozone recovery and climate action.
Key Points at a Glance
- Healing the ozone hole can reverse its past damage to Southern Ocean circulation and carbon uptake.
- The Southern Ocean absorbs a large share of global atmospheric carbon, slowing climate change.
- Future carbon uptake depends more on greenhouse gas levels than on ozone recovery alone.
- Lower emissions lead to better ocean carbon absorption by minimizing disruptive wind patterns.
- Study used simulations spanning 1950–2100 to explore ozone and emissions scenarios.
Once a symbol of environmental catastrophe, the ozone hole may now hold a key to climate recovery. A new study by the University of East Anglia and the UK’s National Centre for Atmospheric Science reveals that as the ozone layer heals, it could help the Southern Ocean reclaim its role as a powerful carbon sink—but only if greenhouse gas emissions are brought under control.
The Southern Ocean is a marvel of the global climate system. Although it surrounds just a single continent—Antarctica—it absorbs a disproportionately large share of atmospheric carbon, helping to regulate Earth’s temperature and buffer the effects of climate change. But that crucial function has been under strain. For decades, ozone depletion in the stratosphere has intensified winds over the Southern Ocean, pulling carbon-rich deep water to the surface. This upwelling process makes it harder for the ocean to absorb additional carbon from the air.
Now, using simulations from an Earth system model (UKESM1), researchers have reconstructed how the Southern Ocean has behaved from 1950 through today—and how it might behave through the end of the century under different emissions and ozone scenarios. Their findings, published in Science Advances, offer a rare piece of good news in the climate story: the disruptive effects of the ozone hole on ocean carbon uptake are reversible.
Lead author Dr Tereza Jarníková explains, “The loss of ozone led to stronger winds that reduced the ocean’s ability to absorb carbon. But as the ozone heals, that pattern begins to reverse—especially if greenhouse gas emissions remain low.”
The team modeled three versions of the ozone layer: one where the ozone hole never opened, one matching real-world conditions (with a healing ozone layer post-Montréal Protocol), and one where the ozone hole stayed the same size as it was in 1987. They then ran each of these ozone scenarios against two greenhouse gas futures—one optimistic, the other bleak.
The results are revealing. In scenarios with lower greenhouse gas emissions, the ocean shows a much stronger rebound in carbon uptake, as calmer winds no longer churn up deep waters and disrupt surface absorption. In high-emission scenarios, however, the healing ozone layer isn’t enough to counteract the increasingly chaotic winds driven by climate change.
Dr Jarníková adds, “In the future, it’s not ozone that dominates the winds, but greenhouse gases. That means what happens to emissions now is critical for the Southern Ocean’s ability to mitigate climate change.”
Another important insight: the influence of changing ocean circulation on carbon uptake may decrease over time, due to shifts in how carbon is distributed between the surface and the deep ocean. This suggests that even if wind patterns stabilize, the ocean’s capacity to draw down carbon could still decline if emissions remain high.
The study underscores the complex but vital interplay between atmospheric chemistry and ocean physics. It also highlights the long-term value of international agreements like the Montréal Protocol, which helped stop the spread of ozone-depleting substances and paved the way for healing.
But while the ozone layer is recovering, the climate crisis continues. The study’s central message is clear: the Southern Ocean can be a powerful ally in absorbing carbon—but only if we make choices now that enable it to do so.
Source: University of East Anglia
