Separating CO₂ emission from removal targets comes with limited cost impacts

Area of Science:

• Climate Science
• Environmental Economics
• Integrated Assessment Modeling

Background:

• Nations increasingly adopt net-zero targets, but the balance between emissions reduction and carbon dioxide removal (CDR) remains unclear.
• Current integrated markets for emissions and removals may overemphasize CDR due to unaddressed sustainability risks.

Purpose of the Study:

• To analyze the implications of segregated targets for emissions and novel CDR within global net-zero pathways.
• To evaluate the economic efficiency and sustainability trade-offs of separating CDR targets.

Main Methods:

• Utilized the Integrated Assessment Model REMIND to simulate global net-zero emissions pathways.
• Compared scenarios with integrated emissions and removals markets against those with separated targets.

Main Results:

• Separating CDR targets from emissions reductions results in moderate efficiency losses.
• Limiting CDR targets increases emission prices but yields benefits like lower cumulative emissions and reduced financial strain on public funds.
• Separation limits reliance on geological CO2 storage but does not reduce biomass demand.

Conclusions:

• Segregated targets for emissions and CDR offer a viable strategy for achieving net-zero, balancing economic efficiency with sustainability.
• Policy design must ensure adequate CDR deployment for achieving net-negative emissions by mid-century while considering biomass implications.