Singapore’s approach to net zero is often summarised as “decarbonise fast, then deal with the rest.” The Equatic–PUB–UCLA partnership¹ underway at Tuas operationalises that second clause: a government-backed, scientifically grounded programme to remove and durably store carbon in the ocean while co-producing hydrogen; precisely the kind of solution that can neutralise residual emissions from sectors where abatement is brutally hard.

From pilot to playbook: Singapore is building a government-backed ocean-CDR demo that actually scales.

In February 2024, PUB announced “Equatic-1,” a US$20 million demonstration plant co-funded with the National Research Foundation and UCLA’s Institute for Carbon Management. The system is designed to remove roughly 3,650tCO₂/year and co-produce ~105 t of “carbon-negative” hydrogen/year, sited at PUB’s Tuas R&D facility to plug into existing water-treatment and desalination infrastructure. Technically, the plant uses selective anodes(ARPA-E supported) to avoid chlorine by-products during seawater electrolysis - a gating issue for ocean deployments. Carbon is stored as stable Ca/Mg carbonates with a 10,000-year permanence claim¹.

This sits on top of clear policy scaffolding. Singapore’s carbon tax is stepping up (S$25/tCO₂e in 2024–25; S$45 in 2026–27; S$50–80 by 2030)^2,3, with up to 5% of liabilities met via high-quality international credits.That combination - public co-funding, a demonstration-first posture, and price signals, creates a credible pathway from pilot to playbook.

The physics behind the promise:mineralising CO₂ in seawater delivers durable tons and clean molecules.

Electrochemical ocean CDR(carbon dioxide removal) splits seawater into acidic and basic streams. Managed correctly, the process either mineralises CO₂ as solid carbonates or increases alkalinity so the ocean can hold more dissolved inorganic carbon (as bicarbonate/carbonate ions). The durability case is strong: mineral forms and dissolved bicarbonate pathways are expected to retain CO₂ on millennial timescales when properly implemented; PUB’s project communication describes ≥10,000 years for the mineral route¹.

The engineering is electricity-intensive, so grid carbon intensity is pivotal.

With Singapore’s grid emission factor⁴ at 0.412 kgCO₂/kWh in 2023, the net-removal balance depends on the plant’s kWh per tonne removed and power-sourcing strategy (e.g., low-carbon imports or PPAs as they expand). One differentiator for Equatic is the hydrogen co-product; while avoided emissions from displacing grey H₂ typically sit outside CDR MRV, the revenue and system-benefit potential are real; particularly in an industrial hub. Energy Market Authority

Where it really bites: this is the neutraliser hard-to-abate sectors can finally plan around.

Even in aggressive decarbonisation scenarios, residual emissions persist in aviation, cement, steel, shipping and parts of chemicals. For boards in these value chains, “net zero” only closes when residuals are neutralised by durable, audit-ready removals. Ocean mineralisation answers that brief:the credits are high-durability and generated in auditable industrial systems, and the pathway is being de-risked under a public-interest umbrella. The World Economic Forum’s tracker underscores the stakes: eight hard-to-abate sectors collectively contribute ~40% of direct CO₂e today⁵.

Aviation offers a concrete signal. Boeing⁶ has agreed to a pre-purchase with Equatic covering 62,000 t of removals and 2,100 t of hydrogen - a market pointer from a real buyer, not just a grant.

Beyond accounting tricks: here’s what counts as real net zero, and how this stacks up.

Three tests matter to directors and auditors:

1. Permanence: Solid carbonates and long-lived dissolved storage beat most land-based stocks on reversal risk⁸.
2. MRV: Metered electricity, measured carbonate formation, and hydrogen yields support clear, auditable tonnes; leading policy briefings emphasise measurability, verifiability and permanence as bar-setting criteria for ocean CDR pilots⁹.
3. Governance: Public-sector co-funding and siting at a national water agency facility anchor the project in regulatory oversight, and not just a private claim¹.

None of this removes the need for caution.

‍Reuters⁷ reported Singapore’s intent to expand ocean-CDR pilots as 200+ scientists urged accelerated, carefully governed research to validate efficacy and manage ecological risk - exactly why Singapore’s pilot → demo → commercial sequence, with impact monitoring at each step, is the right posture.

Trees, tech, and time horizons: what wins over 5, 15, and 50 years.

0–5 years (short term)
Afforestation and urban tree-planting deliver immediate local co-benefits - shade, microclimate cooling, biodiversity, and begin to accumulate carbon. Singapore’s OneMillionTrees movement shows how this builds resilience and quality of life. But from a ton-for-ton perspective, sequestration starts modestly and is sensitive to survival rates in early years. Ocean CDR modules, by contrast, yield auditable tonnes from day one with no land take, important in a dense city-state (net-removal still hinges on power mix).

5–15 years (mid term)
Tree growth and stocks build, but reversal risks (fire, disease, pests) and land competition remain structural constraints at scale, as well-documented in the IPCC assessments. Electrochemical ocean CDR can expand modularly alongside desalination and port infrastructure, and its storage is far less exposed to biophysical reversal. The key bottlenecks here are engineering: kWh per tonne, component durability and capex learning curves; precisely what the Tuas demonstration is designed to de-risk¹⁰.

15+ years (long term)
Forest systems saturate and sequestration rates flatten; climate-driven disturbances can erase gains quickly. Trees remain essential for adaptation and biodiversity and should be funded on those merits. But for century-scale, bankable mitigation, long-lived mineral or dissolved storage offers a firmer basis for balancing residuals in perpetuity, especially for national strategies and corporate claims that must withstand scrutiny for decades¹⁰.

Counting the dollars and kilowatts:the economics that make or break ocean CDR.

The near-term cost stack is dominated by electricity and electro-chemical hardware. As an illustrative check: at ~1,500 kWh/tCO₂, every ~S$0.28–0.30/kWh retail-tariff assumption implies ~S$420–450 per ton for electricity alone before opex/capex recovery; actual industrial rates vary.

The levers are clear: (i) process efficiency & runtime; (ii) stack life; and(iii) revenue synergies from hydrogen or (where permitted) carbonate co-products. Singapore’s regulated household tariff has hovered around ~28–30SG¢/kWh in 2024–2025, and the grid EF¹² context above helps frame net-removal math for early plants.

For boards, the focus over the next 12–24 months: audited kWh/tCO₂,verified net-negativity under grid conditions, and stack/module reliability, all trackable in a governed demo.

Bottom line: a measured, public-interest path to bankable, century-scale tons.

Net zero is an accounting identity anchored in physics. Singapore’s ocean-CDR programme makes that identity achievable for sectors that cannot fully abate by 2030–2040. It combines durable storage, auditable tonnes, public-interest governance, and real buyer demand, inside a carbon-pricing framework that rewards high-integrity outcomes. Keep planting urban forests for resilience and liveability - they are essential public goods. But to close corporate and national carbon ledgers with confidence, especially for aviation, cement, steel, shipping and chemicals, the PUB–Equatic–UCLA pathway is a genuine solution. It is being proven, deliberately and transparently, in Singapore.

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References

1. PUB. “PUB partners UCLA ICM and Equatic to build world’s largest ocean-based carbon dioxide removal demonstration plant in Singapore.” Media release, 27 Feb 2024. PUB, Singapore’s National Water     Agency
2. NCCS (Gov.sg). “Carbon Tax”—levels     and up to 5% credit use. Accessed 2025. National Climate Change     Secretariat
3. NCCS (Gov.sg). “Singapore will raise climate ambition…” (carbon tax trajectory: S$25 → S$45 → S$50–80). 18 Feb 2022. National Climate Change     Secretariat
4. EMA. “Singapore Energy Statistics 2024 — Chapter 2” (Grid Emission Factor 0.412 kgCO₂/kWh for 2023). Energy Market Authority
5. World Economic Forum. “Net-Zero Industry Tracker 2024” (hard-to-abate sectors ≈ 40% of direct CO₂e). 12 Dec 2024. World Economic Forum
6. Boeing / Equatic. “Pre-purchase option agreement: 62,000 t CDR + 2,100 t H₂.” 31 May 2023. Equatic
7. Reuters. “Singapore to expand ocean CO₂-removal project as scientists call for more research.” 5     Sep 2023. Reuters
8. National Academies / NCBI     Bookshelf. “Ocean Alkalinity Enhancement” (permanence on millennial     timescales). 2021/updated. NCBI
9. EESI Briefing. “Demystifying  Ocean Carbon Dioxide Removal” (MRV qualities for credible CDR). 16     Apr 2024. Environmental and Energy Study     Institute
10. IPCC AR6 WGIII. “Chapter 12:  Cross-sectoral perspectives” (A/R reversal risks; land competition). 2022.     IPCC
11. NParks. “OneMillionTrees  movement—About the movement.” Accessed 2025. Default
12. EMA / SP Group. “Regulated electricity tariff (historical context 2024–2025).”  Energy Market Authority+1
13. Ocean Visions. “More than 200 scientists call for accelerated and expanded ocean-based CDR research.” 5 Sep 2023. Ocean Visions

Author: Bitasta Roy Mehta

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