Fig. 5: Comparison of CO₂ abatement potentials, abatement costs and technology contributions under different policy scenarios.

a,b, Global CO₂ emissions and production costs of all steel plants during 2020–2050 under the least-cost pathways with varying policy strengths (late, medium and early). The numbers in yellow, green and purple indicate differences between adjacent scenarios: cumulative CO₂ abatement and average abatement cost (a) and increases in total production cost (b), corresponding to the areas between neighbouring solid lines. c, Abatement potentials and abatement costs of different decarbonization technologies worldwide and in major regions over 2020–2050 under the late, medium and early scenarios, compared with reference pathways without policy intervention.