What are the biggest CO₂-emitting factories in the world?
The biggest CO₂-emitting factories are steel mills — led by POSCO Gwangyang steel plant (South Korea, ~34.8 Mt CO₂e/yr) — followed by major oil refineries, chemical complexes and cement kilns. Heavy industry's carbon sits in a finite, nameable set of facilities, many of which individually out-emit the power stations we usually worry about.
Highest-emitting industrial facilities (CO₂e/yr)
Source: Climate TRACE v6 (CC BY 4.0). Modelled estimates.
Process emissions, not just fuel
Steel, cement, refineries and chemicals dominate because much of their CO₂ comes from chemistry — coke in steel,
calcination in cement — not only from burning fuel. That makes heavy industry the hardest sector to abate and the
place where every efficiency gain counts most.
Cement is ~7-8% of global CO₂
Cement is more distributed than steel, but the biggest single kilns still rank among the largest point sources, and
the sector as a whole is roughly 7-8% of global CO₂.
