Melting Antarctic ice sheets will slow Earth’s strongest ocean current
93% of the excess heat in the climate system ends up in the ocean, and a slowdown of the Antarctic Circumpolar Current (ACC), the world’s strongest ocean current, affects its ability to act as a carbon sink. A recent study from an improved ocean model has shown this slowdown by around 20% by 2050 in a high carbon emissions scenario. The results of the study indicate a potential decrease in the ocean’s capacity to buffer us from the impacts of climate change globally. However, there might be a sliver of hope in preventing these ice melts if urgent action to reduce emissions is taken by corporations.
University of Melbourne researchers, fluid mechanist Associate Professor Bishakhdatta Gayen and climate scientist Dr Taimoor Sohail, and oceanographer Dr Andreas Klocker from the NORCE Norwegian Research Centre, undertook the research. They analysed a high-resolution ocean and sea ice simulation of ocean currents, heat transport and other factors to diagnose the impact of changing temperature, saltiness and wind conditions.
In an exclusive interview with Carbon Wire, Dr. Taimoor Sohail explained the urgency of the matter and the level of commitment and funding required to mitigate the effects suggested in the study.
Understanding the Issue: The Role of the ACC and Ice Sheet Melting
Dr. Sohail explained that the ocean absorbs a huge proportion of heat through the ACC’s circulation patterns. It is a critical component of the global circulation system, connecting different ocean basins. “A slowdown in the ACC could impact the ability of the ocean to absorb excess heat and carbon. This would amplify climate change by allowing more heat to stay in the atmosphere instead of being trapped in the ocean,” he said.
In addition to that, the ACC helps in certain regions around Antarctica to keep warm ocean water away from the ice sheets. In Antarctica, ice sheets melt from below through a process called basal melting. A recent study has suggested that West Antarctic ice melting may already be locked in, meaning there may be limited intervention possible in that region. However, the uncertainty around future ice melt projections presents an opportunity for aggressive carbon emissions reductions to mitigate the effect.
Challenges in Scientific Communication and Policy Action
Policymakers often refuse to take results from such global impact studies seriously as they require more localized evidence. “This is a major challenge because translating global impacts into a local landscape requires its own level of commitment and funding. However, ecosystems are interconnected, and given that climate change is a global issue, policymakers need to take these global results into account,” Dr Sohail said.
Technological Advancements Needed for Better Analysis in the Southern Ocean
Assessing what is happening in the Southern Ocean requires continuous, long-term, high-resolution data observations. Currently, scientists rely on satellite data for surface-level monitoring, but much of what happens below the ocean remains a mystery. The deep ocean, where significant heat is stored over long timescales, is largely unexplored due to limitations in observational technology.
Autonomous floats like Argo floats only reach depths of 2,000 meters, whereas most of the ocean extends to 4,000-5,000 meters, with extreme depths reaching over 11,000 meters. The absence of deep-sea observational networks presents a major gap in climate studies. New technology like Deep Argo probes, which can reach 4,000 meters, represents a significant improvement but is costly to implement.
Additionally, hostile environmental conditions and sea ice create further obstacles to data collection. Consistent, year-round observations—especially during harsh winter months—are crucial for understanding long-term climate trends. While historical data from the 1950s and 1960s is limited, advancements in machine learning and artificial intelligence could help fill in gaps, improving climate models.
Integrating an ice sheet model into the current model would provide higher accuracy, and this is where the future of the model lies. Dr. Sohail hopes to incorporate other earth system models to refine projections further.
What Needs to Be Done
- Policymakers need to take scientific studies seriously and integrate global findings into local policymaking.
- Corporations must take urgent action to reduce emissions to slow down the rate of ice sheet melting.
- The scientific community needs more collaboration and funding to improve observational models and better analyze climate projections.
- Investment in technology such as Deep Argo and ice sheet models is necessary to enhance accuracy in climate forecasting.
The Importance of Continued Collaboration and Funding in the Scientific Community
It is important to highlight that this research is the result of a strong collaborative network. The model itself was developed by researchers at UNSW and supported by experts from ANU, the University of Tasmania, and a consortium of over 100 scientists working together to improve climate models.
Dr Sohail said that consistent funding of climate science is essential for a variety of reasons. “Observational data is necessary not just for understanding the present but also for reconstructing the past and predicting the future,” he said. Collaborations between climate scientists, fluid mechanics experts, and oceanographers — such as the work of Dr. Sohail, Associate Professor Bishakhdatta Gayen, and Dr. Andreas Klocker — demonstrates how interdisciplinary research can lead to significant findings.
Climate change is a global problem — one that is complex, urgent, and requires a concerted effort across scientific disciplines, policymakers, and industries. Continued investment in climate science and technology is critical in ensuring that mitigation strategies can be implemented effectively to combat climate change.