Antarctic Circumpolar Current’s 34-million-year rise: How tectonic shifts and CO₂ decline forged Earth’s climate regulator

Indigenous Antarctic knowledge systems, such as those of the Yaghan people of Tierra del Fuego, describe the Southern Ocean’s currents as sentient forces tied to ancestral memory and seasonal rhythms. These perspectives contrast with the ACC’s reduction to a ‘mechanism’ in Western science, ignoring how local communities have historically navigated its eddies and upwellings. The erasure of Indigenous voices in Antarctic research reflects a broader colonial legacy in climate science, where data is extracted without reciprocity.

The ACC’s formation 34 million years ago aligns with the Eocene-Oligocene transition, when tectonic shifts (Drake Passage opening) and CO₂ decline triggered Antarctic glaciation—a precedent for today’s anthropogenic CO₂ rise. Comparable gateway closures, like the Isthmus of Panama’s formation 3 million years ago, demonstrate how ocean currents reorganize global climate systems over geological timescales. These historical parallels reveal the ACC as part of a dynamic, interconnected Earth system rather than an isolated phenomenon.

Pacific Island navigators, such as the Māori of Aotearoa/New Zealand, have long mapped the ACC’s currents as part of *wayfinding* traditions, linking oceanic patterns to celestial navigation. In contrast, Western science’s focus on the ACC’s ‘discovery’ in the 19th century ignores these embodied knowledges, framing the current as a ‘resource’ for exploitation rather than a living system. Cross-cultural comparisons show how Indigenous and Western frameworks can complement each other in understanding oceanic dynamics.

The ACC’s role in global heat transport and carbon sequestration is well-documented, with studies showing it accounts for 90% of the Southern Ocean’s meridional overturning circulation. Sediment core data from the Drake Passage confirm its intensification 34 million years ago, correlating with Antarctic ice sheet growth. However, most research underestimates the ACC’s sensitivity to future warming, particularly its potential collapse under 2°C scenarios, which could disrupt global climate patterns.

In Inuit cosmology, the Southern Ocean is a liminal space where spirits traverse between worlds, with currents like the ACC acting as conduits for ancestral communication. Contemporary artists, such as the Māori collective *Te Huringa o Te Tai*, depict the ACC’s turbulence as a metaphor for cultural resilience in the face of climate change. These artistic interpretations challenge the reductionist framing of the ACC as a purely physical system, inviting a more holistic engagement with oceanic forces.

Climate models project the ACC could weaken by 30% by 2100 under high-emission scenarios, disrupting global heat distribution and accelerating Antarctic ice melt. Scenario planning must integrate Indigenous knowledge systems to anticipate non-linear changes, such as shifts in marine biodiversity that could destabilize Southern Hemisphere fisheries. The ACC’s future is also tied to geopolitical decisions about Antarctic governance, where resource extraction could further alter its dynamics.

Southern Cone nations (Chile, Argentina) and Pacific Island communities are disproportionately affected by ACC-driven climate shifts but lack representation in research agendas. Indigenous Antarctic researchers, such as those from the Yaghan and Selk’nam peoples, are rarely included in studies despite their ancestral ties to the region. The exclusion of these voices reinforces a colonial narrative that treats the ACC as a ‘global commons’ to be managed by Northern institutions, rather than a system with local stewards.