Natural Carbon Sinks Absorb 40% of CO2 Emissions but Undervalued in Climate Models
Event summary
- Natural carbon sinks absorbed 40% of human CO2 emissions in 2025, reducing net emissions from 48 GtCO2 to 30 GtCO2 annually.
- Engineered removals contributed only 0.08 GtCO2 in 2025, 200,000 times less than natural absorption.
- Five major Earth system tipping points carry a combined greenhouse gas release potential exceeding 750 GtCO2.
- Carbon prices in compliance markets (US$5–US$90 per tCO2) insufficiently reflect the cost of sink degradation.
- Forest area has declined by 1.5 million km2 since 1990, with deforestation contributing 5–6 GtCO2 annually.
The big picture
Wood Mackenzie's report highlights a critical disconnect between the reliance on natural carbon sinks and their undervaluation in climate models. While engineered removals remain minimal, the degradation of natural sinks—such as forests and oceans—poses a structural risk to global net-zero targets. The report underscores the urgency of policy action and scaled financing to protect these unpriced assets, as their collapse could undermine climate mitigation efforts.
What we're watching
- Policy Gaps
- Whether current carbon pricing frameworks will be revised to reflect the true cost of sink degradation.
- Ecosystem Collapse
- The pace at which natural sinks weaken due to inaction, particularly in the 2026–2035 window.
- Investment Shifts
- How early movers in verified nature-based solutions and sink-linked carbon instruments capture value.