MACC (Marginal Abatement Cost Curve): This curve helps policymakers and investors prioritize decarbonization actions by showing the cost per tonne of CO₂e abated and the total abatement potential for each measure.
- Negative cost (below axis): Measures that save money (e.g., energy efficiency).
- Positive cost (above axis): Measures that require investment (e.g., CCS, some renewables).
- Bar width: The bigger the bar, the more emissions that action can abate.
- Investment opportunities: The pie chart shows how investment needs are distributed across sectors (energy efficiency, renewables, transport, CCS, nature-based solutions). This links cost-effective abatement to capital allocation, supporting strategic investment and policy planning.
- Application: MACCs are widely used in policy, corporate strategy, and sustainable finance to maximize climate impact per dollar spent, identify “low-hanging fruit,” and plan the transition to net zero.