Cement After CBAM: The 2026 Decarbonization Capital Stack

The 4.1 Billion Tonne Baseline #

Cement is the second most consumed material on Earth after water, and the largest industrial CO2 emitter after iron and steel. Per USGS Mineral Commodity Summaries 2025, world hydraulic cement output in 2024 was about 4.1 billion tonnes. China produced 2.0 billion tonnes (roughly 49 percent), India 390 million tonnes, the United States 91 million tonnes, Vietnam 120 million tonnes, and Turkey 81 million tonnes. China continues to drift down from a 2014 peak above 2.5 billion tonnes as property activity contracts. India is now the only major market expected to add net capacity through 2030, with growth tracking 6 to 7 percent annually.

Per tonne of cement produced, average CO2 emissions sit near 0.6 tonnes (GCCA Getting the Numbers Right 2022 data, IEA Cement Roadmap). About 60 percent of those emissions are process emissions from calcination of limestone (CaCO3 to CaO plus CO2), which no fuel switch can address. The remaining 40 percent comes from kiln thermal energy, mostly coal and petcoke. Multiplying intensity by volume, the sector emits roughly 2.4 to 2.6 gigatonnes of CO2 each year, or 7 to 8 percent of global anthropogenic CO2 (IEA, GCCA). The Global Cement and Concrete Association Concrete Future roadmap commits members to net zero by 2050, with a 25 percent reduction in cement and concrete CO2 by 2030 from a 2020 baseline.

The stakes are large. At an OECD ex works price of 110 to 130 dollars per tonne, cement is a 500 to 600 billion dollar industry. A 90 euro EU ETS allowance applied to 0.6 tonnes intensity equals 54 dollars of CO2 cost per tonne of cement, or 40 to 50 percent of the gate price. CBAM equalization, definitive from January 2026, makes that the competitive floor at Rotterdam, Antwerp, and Koper.

Clinker Substitution: LC3, GGBS, Fly Ash #

Because two thirds of cement emissions come from clinker, the cheapest decarbonization lever is to use less of it. The global average clinker to cement ratio in 2022 was about 0.71 (GCCA GNR), down from 0.83 in 1990. The IEA Cement Roadmap requires that ratio to fall to 0.65 by 2030 and 0.57 by 2050 to stay on a net zero pathway. Three substitutes carry the load: limestone calcined clay cement (LC3), ground granulated blast furnace slag (GGBS), and coal fly ash.

LC3, developed by EPFL with partners in India and Cuba, replaces up to 50 percent of clinker with calcined kaolinitic clay and limestone, cutting CO2 per tonne by 30 to 40 percent at OPC equivalent strength. Holcim sells it under the ECOPlanet brand from calcined clay lines in Cote d'Ivoire, Colombia, and France. GGBS, a steel byproduct, substitutes 30 to 70 percent of clinker but is supply constrained as blast furnaces decline. Fly ash supply is also peaking with OECD coal retirements (the US shed roughly 100 GW of coal capacity from 2014 to 2024, per EIA).

The arithmetic is decisive. A 30 percent clinker substitution at 0.6 tonnes per tonne intensity saves 0.18 tonnes of CO2 per tonne of cement. At 90 dollars EU ETS, that is 16 dollars saved per tonne against a 5 to 8 dollar calcined clay processing premium. LC3 pays back at any carbon price above 50 dollars. EU public works and the EIB are already writing CEM II/C and CEM VI specifications into tenders, accelerating pull through demand.

CCS Pioneers: Brevik, Zelo, Rugby #

For the residual process emissions, no chemistry shortcut exists, only carbon capture. The first industrial scale cement CCS plant, Heidelberg Materials Brevik in Norway, achieved start of operations in 2024 with a nameplate capture capacity of approximately 400 kilotonnes of CO2 per year, equivalent to about 50 percent of the plant's CO2. The captured stream is liquefied and shipped to the Northern Lights terminal at Oygarden for permanent geological storage in the North Sea Aurora reservoir. The total project cost was around 400 million euros, with about 25 percent funded by the Norwegian state Longship program.

Holcim's Zelo Buon Persico facility in Lombardy, Italy, advanced through FEED and front end engineering in 2024 with a target of 1.4 million tonnes CO2 per year capture capacity, supported by an EU Innovation Fund grant under the GeZero project (formerly known as the Holcim Zelo CCUS proposal). Cemex's Rugby plant in the United Kingdom is deploying Carbon8 mineralization technology integrated with a planned amine capture train, while the Heidelberg Padeswood plant in Wales, awarded a roughly 350 million pound HyNet cluster CCS connection, expects first capture in 2028. CRH's Mitchell, Indiana plant is advancing with an Air Liquide Cryocap front end. Each project benefits materially from the IRA Section 45Q credit at 85 dollars per tonne for sequestered industrial CO2 (the Inflation Reduction Act amended 2022 levels from 50 dollars), pushing a 1 million tonne per year project to 85 million dollars of annual federal tax credit, indexed for inflation through 2032.

The Policy Stack: 45Q and CBAM #

Two policy regimes now anchor cement decarbonization economics. In the United States, IRA Section 45Q, as amended by Public Law 117-169 in August 2022, raised the credit for CO2 captured from industrial point sources and geologically sequestered to 85 dollars per tonne (up from 50 dollars), and to 60 dollars per tonne for utilization. The credit is direct pay eligible for the first five years for tax exempt entities and transferable for taxable entities, removing the historical tax equity bottleneck. Construction must begin before 1 January 2033 to qualify. For a typical 1 million tonne CO2 cement CCS project, 45Q delivers 850 million dollars of nominal credit value over a 10 year crediting window, materially closing the cost gap to coal cement gate prices.

In the European Union, the Carbon Border Adjustment Mechanism (Regulation 2023/956) covers cement (CN codes 2523), iron and steel, aluminium, fertilizers, hydrogen, and electricity. The transitional phase, since 1 October 2023, requires importers to report embedded emissions but with no financial obligation. From 1 January 2026 the definitive phase begins: importers must purchase CBAM certificates priced to the weekly EU ETS auction average, with free EU ETS allowances for cement phasing out in parallel from 2026 to 2034. With ETS prices in the 80 to 100 euro per tonne range, the CBAM tariff equivalent on a tonne of imported clinker, embedded with about 0.86 tonnes of CO2, is 70 to 86 euros, or roughly half the FOB price of Turkish or North African clinker cargoes. EU domestic producers gain pricing room equivalent to the carbon cost they already bear.

Other regimes complement these anchors. India's Perform Achieve and Trade scheme has set successive cement specific energy consumption targets across PAT cycles, with PAT VIII running 2024 to 2027 covering 134 cement designated consumers (Bureau of Energy Efficiency). The Saudi Arabia gigaprojects, NEOM, Diriyah Gate, Qiddiya, Red Sea, are pulling Gulf cement demand to record highs (Yamama Cement and Saudi Cement Company reported 2024 utilization above 80 percent for the first time since 2015), creating a regional appetite for Saudi Green Initiative aligned low carbon binders that Holcim, Heidelberg, and the local champions are racing to supply.

Novel Chemistries: Sublime, Brimstone, Solidia #

Beyond clinker substitution and post combustion CCS, a cohort of US startups is pursuing chemistry redesign. Sublime Systems, a 2020 MIT spinout in Somerville, Massachusetts, makes cement at ambient temperature via electrolysis, bypassing calcination. The company secured a Department of Energy Industrial Demonstrations Program award of up to 87 million dollars in 2024 for a 30,000 tonne per year first commercial plant in Holyoke, with offtake from Microsoft for data center concrete.

Brimstone, an Oakland firm, produces ordinary Portland cement from calcium silicate rocks rather than limestone, eliminating process CO2 and yielding a magnesium oxide co product that absorbs additional CO2. Brimstone received a 189 million dollar IDP award in 2024. Solidia Technologies (Piscataway, New Jersey) commercialized a calcium silicate clinker that cures by CO2 absorption rather than hydration, locking carbon in finished products. CarbonCure, based in Halifax, retrofits ready mix plants to inject captured CO2 into fresh concrete and is deployed at over 800 plants across North America, Asia, and Europe.

These technologies do not yet compete on cost with optimized OPC at scale, but they do not need to. Voluntary procurement premiums from Microsoft, Meta, Amazon, and Stripe Frontier (collectively committed to over 12 billion dollars of carbon removal and low carbon material purchases through 2030) effectively underwrite the first three to five commercial scale plants. The IRA combined with state low carbon concrete procurement (California Buy Clean, Colorado, New York, Minnesota) creates a domestic pull market that European and Asian incumbents do not enjoy, accelerating US capital deployment in novel cement.

The 2030 Trajectory #

The IEA Net Zero Emissions cement pathway requires direct emissions to fall from about 2.4 gigatonnes in 2022 to 1.7 gigatonnes by 2030, a 30 percent reduction even as global cement output stays roughly flat in volume terms. The GCCA roadmap targets a 25 percent CO2 cut by 2030. Both pathways require, in round numbers, 60 percent of the lift from clinker substitution and efficiency, 25 percent from kiln fuel switching (alternative fuels and electrification), and 15 percent from CCS. By 2050, CCS share rises to about 36 percent of total abatement under IEA NZE.

The implication for clients is sharp. Cement producers face a closing window to lock in capture sites at industrial clusters (HyNet, Northern Lights, Porthos, Bayou Bend) and to write LC3 and CEM VI products into infrastructure procurement specifications before EU ETS free allowances disappear by 2034. For asset owners and lenders, project finance for cement CCS is now bankable on the 45Q strip in the United States and on the EU Innovation Fund plus ETS arbitrage in Europe, with risk concentrated in CO2 transport and storage rather than capture itself. For procurement leaders in tech, real estate, and public works, the question is no longer whether to specify low carbon concrete, but how to price it: voluntary premiums of 50 to 150 dollars per cubic metre fund first of a kind plants, while CBAM aligned tendering does the heavy lifting at scale. Argus tracks this convergence, calcination, capture, and capital, as the defining industrial transition story of the second half of the 2020s.

Sources #

• USGS Mineral Commodity Summaries 2025, Cement
• GCCA Concrete Future, Roadmap to Net Zero
• GCCA Getting the Numbers Right (GNR) database
• IEA Technology Roadmap, Low Carbon Transition in the Cement Industry
• European Commission, Carbon Border Adjustment Mechanism
• Heidelberg Materials, Brevik CCS
• Northern Lights JV, Aurora storage
• US IRS Section 45Q, Inflation Reduction Act of 2022
• EU Innovation Fund, GeZero project award
• Holcim ECOPlanet and Zelo Buon Persico CCUS
• Cemex Rugby with Carbon8 mineralization
• Bureau of Energy Efficiency India, PAT scheme