In brief
On 5 November 2026, Australia approved a 1,200‑km southeast of Perth seabed tract for Mitsubishi Heavy Industries to store up to 443 million metric tons of CO₂ in a salt cavern two miles below sea level. The deal supports the country’s 2050 net‑zero goal, could create 4,000 jobs, and signals international cooperation in offshore carbon capture and storage. The project follows a 2021 audit identifying the site as safe and brings together Australian and Japanese industry.
Australia approved a 1,200‑km offshore tract off Perth’s coast for Mitsubishi Heavy Industries to store carbon dioxide in a subterranean salt cavern, a move that fits the nation’s 2050 net‑zero emissions target and tests the viability of large‑scale offshore carbon capture and storage (CCS).
CCS captures CO₂ at the source, compresses it, transports it—usually by pipeline—and injects it into deep formations where it is trapped and prevented from re‑emerging. The site chosen for this effort is a natural salt cavern about two miles beneath the ocean floor, a type of formation well‑suited for long‑term storage because its layers of salt act like a geological cap.
Located roughly 120 kilometres south‑east of Perth in the Indian Ocean, the tract sits within the Coastal and Deepwater Resources Administration’s jurisdiction and was identified during a 2021 Australian government audit of potential offshore storage sites. The audit concluded the cavern’s geology and depth provide a safe seal for CO₂, which will be injected under controlled pressure to keep the gas tightly contained.
The facility will store up to 443 million metric tons of CO₂—an amount reported as 488 million tons in some sector analyses—over its operational lifetime. Those figures represent the chemical mass of the gas that can be injected and are roughly equivalent to the annual emissions from 3.9 million cars in Australia.
Mitsubishi will move the CO₂ from its industrial plants near inland sites to the coast via a dedicated pipeline, then into the oceanic conduit that delivers the gas to the seabed cavern. The project’s engineering team will monitor pressure, temperature, and CO₂ distribution to ensure long‑term integrity, following international best practices adopted by the Global CCS Institute.
Experts cited the 2021 audit as a key sign that the site meets safety thresholds for both operators and regulators. “The cave’s salt layers act as a natural seal, preventing the gas from migrating to the surface or into potable aquifers,” said a senior environmental scientist involved in the audit. The assessment also quantified the cavern’s capacity and projected seal‑gas behavior over a century.
Beyond emissions control, the Australian government sees the project as a catalyst for economic development. According to the Associated Press, the agreement could generate up to 4,000 jobs over the next decade, ranging from engineering and construction to operations and maintenance. Those positions would largely be filled by local workers, providing a boost to employment in Western Australia’s coastal regions.
Dan Collins
It shows that Australia can work with partners abroad to tackle carbon emissions while creating new business opportunities. The technology is mature, and this is the first step in a broader approach to onshore and offshore storage.
Japan’s heavy‑industry sector, which emits large amounts of CO₂, stands to benefit from the collaboration. Mitsubishi’s plants in Japan will off‑load carbon that would otherwise be released into the atmosphere, and the partnership provides a symbol of trans‑pacific cooperation in climate policy.
The project aligns with Australia’s national strategy, which seeks to reduce climate risks by investing in clean‑energy technologies and by meeting its 2050 net‑zero pledge. The policy framework also calls for diversified CCS methods, including onshore injection, geological storage, and ocean‑based schemes.
Internationally, the deal underscores the growing confidence in deep‑sea storage as a flexible component of global decarbonisation. While the climate science community continues to explore feed‑stock flexibility, the large‑scale injection of CO₂ into salt caverns under the ocean presents a rapid pathway to reduce industrial emissions and could inform future policies within the Asia‑Pacific region and beyond.
As the project moves from regulatory approval to construction, Australian and Japanese teams will coordinate the detailed engineering, environmental monitoring, and compliance regimes that will govern the facility’s operation. The first injection of CO₂ is expected in the early 2029, with full capacity achieved by the late 2030s; these timelines position the project as a mid‑century milestone in the global shift toward net‑zero emissions.
