This document explores the status quo, challenges, and decarbonization pathways for key industrial sectors that are major contributors to global greenhouse gas emissions. Based on data from the International Energy Agency (IEA) Net Zero by 2050 Roadmap and other sources, we highlight the current state and the technologies and policies needed to achieve net-zero emissions by 2050.
Industry accounts for about 30% of global CO2 emissions. The largest emitting sectors include steel, cement, chemicals, and oil refining. Decarbonization requires a combination of energy efficiency improvements, electrification, hydrogen adoption, carbon capture and storage (CCUS), and material efficiency.
- The steel industry produces around 1.8 billion tonnes of crude steel annually (2025 data).
- Emissions: Approximately 7-9% of global CO2 emissions, primarily from iron ore reduction using coal in blast furnaces.
- Current processes: Blast furnace-basic oxygen furnace (BF-BOF) dominates, accounting for ~70% of production; electric arc furnaces (EAF) use scrap but are limited by scrap availability.
- High energy intensity: Steel production requires significant heat, traditionally from coal.
- Process emissions: CO2 from chemical reactions in iron reduction.
- Capital-intensive: Retrofitting or building new low-emission plants is expensive.
- Supply chain: Dependence on iron ore and coking coal.
- Hydrogen-based direct reduction (DRI-EAF): Replace coal with hydrogen for iron ore reduction. By 2050, aim for 76% of steel production via EAF (IEA milestone).
- CCUS: Capture CO2 from blast furnaces and store it. Target 0% unabated processes by 2050.
- Recycling and scrap use: Increase scrap share to 32% by 2030 (current ~32%, but needs to rise).
- Electrification: Use renewable electricity for EAFs.
- Innovation: Breakthrough technologies like hydrogen DRI at scale.
- Produces ~4 billion tonnes of cement annually.
- Emissions: ~7-8% of global CO2, with ~60% from process emissions (calcination of limestone) and 40% from energy use.
- Current processes: Clinker production in kilns fired by coal or gas.
- Process emissions: CO2 released inherently from chemical reaction (CaCO3 → CaO + CO2).
- Energy-intensive: High-temperature kilns require fossil fuels.
- Global demand: Growing in developing countries for infrastructure.
- CCUS: Capture CO2 from kilns and cement plants. IEA targets 3 Mt CO2 captured by 2030, scaling to 1355 Mt by 2050 for industry.
- Alternative materials: Use supplementary cementitious materials (SCMs) like fly ash, slag, or calcined clays to reduce clinker content.
- Electrification and low-carbon fuels: Switch to electric kilns or hydrogen/ammonia.
- Carbon-neutral clinker: Develop new binders or electrochemical processes.
- Efficiency improvements: Optimize kilns and reduce energy use.
- Produces a wide range of products, including plastics, fertilizers, and pharmaceuticals.
- Emissions: ~4-5% of global CO2, from energy use and process emissions (e.g., steam cracking for ethylene).
- Current processes: Heavy reliance on fossil feedstocks and energy.
- Diverse processes: Hard to abate emissions in some chemical reactions.
- Feedstock emissions: Carbon embedded in products like plastics.
- Energy demands: High heat and electricity needs.
- Electrification: Shift to electric processes where possible, e.g., electric steam crackers.
- Hydrogen: Use low-carbon hydrogen for ammonia and other chemicals. IEA targets 46 Mt H2 demand by 2030 for chemicals.
- CCUS: Capture CO2 from processes. Target 2 Mt captured by 2030.
- Circular economy: Increase recycling of plastics (collection 17%, secondary production 8% by 2030; aim for higher).
- Alternative feedstocks: Bio-based or recycled carbon.
- Innovation: New routes like electrochemical production.
- Includes refining, petrochemicals, and upstream production.
- Emissions: ~10-15% of global CO2, from combustion and fugitive methane.
- Current processes: Fossil fuel-based refining and cracking.
- Fugitive emissions: Methane leaks.
- Refining emissions: High energy use.
- Transition away from fossil fuels: Industry must adapt.
- CCUS: Capture CO2 from refineries and petrochemical plants.
- Electrification and hydrogen: Use for refining processes.
- Methane abatement: Reduce leaks to near zero.
- Biofuels and e-fuels: Transition to low-carbon fuels.
- Efficiency: Improve energy efficiency in operations.
- Produces ~65 million tonnes annually.
- Emissions: ~1-2% of global CO2, mainly from electrolysis in smelters using carbon anodes.
- Energy-intensive: High electricity demand.
- Process emissions: CO2 from anode consumption.
- Renewable electricity: Power smelters with low-carbon grid.
- Inert anodes: Develop carbon-free anodes.
- Recycling: Increase secondary aluminum production.
- CCUS: For any remaining emissions.
- Emissions: ~1% of global CO2, from energy and process (black liquor combustion).
- Energy use in pulping and drying.
- Biomass and electrification: Use bioenergy and electric drying.
- CCUS: Capture emissions.
- Electrification: Increase electricity share in industry from 21% to 46% by 2050 (IEA).
- Hydrogen: Scale up production to 187 Mt by 2050.
- CCUS: Capture 2,800 Mt CO2 annually by 2050.
- Energy Efficiency: Improve intensity by 4% annually.
- Policies: Carbon pricing, subsidies for clean tech, international cooperation.
Decarbonizing industry requires rapid deployment of available technologies and innovation in new ones. Advanced economies must lead, while supporting developing countries. By 2050, industry can be net-zero with the right investments and policies.
Sources: IEA Net Zero by 2050 Roadmap, World Steel Association, IPCC reports.