Making things without carbon

What zero-carbon industry means

Heavy industry emits carbon in two distinct ways, and conflating them is the source of most confused commentary. Energy emissions come from burning fuel for heat and can in principle be electrified. Process emissions come from the chemistry itself — carbon is the reducing agent that strips oxygen from iron ore, and calcining limestone for cement releases CO₂ from the rock regardless of how the kiln is heated. Electrification does not touch the second category. That is why steel and cement are hard in a way that most sectors are not.

Where the science stands

Established Steel is roughly 7% of global energy-related CO₂ emissions and upwards of a tenth of total anthropogenic CO₂, dominated by the blast-furnace route. Cement adds a comparable burden. No net-zero pathway survives leaving either unreformed.

Established Hydrogen direct reduction is the leading answer for steel and it demonstrably works. Replacing carbon with hydrogen as the reductant produces direct reduced iron at metallisation rates above 90%, feeding an electric arc furnace. The saving is close to two tonnes of CO₂ per tonne of steel; each kilogram of green hydrogen displaces roughly 25 kilograms of CO₂. Scandinavian projects have taken this from pilot to commercial-scale construction.

Established Deployed capacity remains very small. Europe held roughly 2.5 million tonnes of hydrogen-DRI capacity in 2025 against global steel production near 1.9 billion tonnes — on the order of a tenth of a percent. Announced targets reach 15–20 million tonnes by 2030, which would be growth of several hundred per cent and still around 1% of global output.

Frontier Economics, not chemistry, is the obstacle. Green steel is more expensive than blast-furnace steel and remains dependent on carbon pricing and state support. Modelling across 300-plus locations finds fossil-free steel could become competitive from around 2030 in favourable places — strong solar, good iron ore, low labour cost, near the tropics — if coking coal prices stay high. That is a conditional forecast, not a trend line.

Frontier For cement the picture is worse. Hydrogen substitution up to 30% of thermal demand is technically viable but economically constrained, with levelised hydrogen costs rising non-linearly; a 30% share would cut US cement sector emissions by around 22%, leaving the process emissions largely untouched. Speculative Molten oxide electrolysis, which eliminates carbon from ironmaking entirely, is cost-prohibitive and not expected commercially before the 2040s. Frontier Retrofitting blast furnaces with carbon capture has not been effectively demonstrated, because the emission points are plural and the flue-gas CO₂ concentration varies.

The binding bottleneck

Established The constraint is cost differential under competition: a producer using clean processes competes globally against one that is not, and no technical advance closes that gap by itself. Frontier Beneath it sits green hydrogen supply — the EU target of 10 million tonnes of renewable hydrogen annually by 2030 is far from being met — and the electricity to make it. Frontier Capital stock turnover is a third constraint: blast furnaces last decades, and the replacement decision happens rarely.

Ethics and governance

Frontier Carbon border adjustment mechanisms are the live policy instrument, and they raise real fairness questions for producers in countries that did not create the historical stock of emissions. Frontier The geography of competitive green steel — near the tropics, where solar is strong, ore is good and wages are low — implies a redistribution of heavy industry that is an industrial-policy question as much as a climate one. Established And there is an honesty issue in labelling: “green steel” covers processes with very different actual emissions, from full hydrogen-DRI to natural-gas DRI with an upgrade path.

Timelines

• 10 yr: Established hydrogen-DRI capacity grows several hundred per cent and remains around 1% of global steel; cement largely unreformed.
• 25 yr: Frontier material share of primary steel decarbonised where power is cheap; cement process emissions still the hard residue.
• 50 yr: Frontier electrolytic ironmaking commercial; alternative cement chemistries at scale.
• 100 / 250+ yr: Speculative industrial systems designed carbon-free from first principles rather than retrofitted.