Perturbed Carbon Cycle

Safe Landing Climates Lighthouse Activity

We will explore the acceptability and climate implications of carbon dioxide removal (CDR) systems (including bioenergy with carbon capture and storage (BECCS)) while maintaining food and water supply, preserving biodiversity, and limiting ocean acidification. A further goal is to assess the risk of surprises or a rapid change in Greenhouse Gases (GHGs), including large or rapid carbon release (e.g., from permafrost melt, large scale fires, or the Southern Ocean), the reversibility of the anthropogenic perturbation, and climate and carbon cycle feedbacks in the context of negative emissions. We will also explore metrics for controlling short- vs. long-lived forcing in the context of negative emissions, and implications for allowable GHG emissions in the context of the Paris Agreement. We will build an understanding of the coupled carbon-energy-water cycle, impact on food, water supply, and biodiversity.

Outcomes:

• Improved observation and modelling of terrestrial biogeochemistry (in particular permafrost) and possible future sources of GHGs, as well as the ocean carbon cycle, especially in the Southern Oceans.
• Improved integration of ocean and land biogeochemistry models within Earth System Models to better constrain the future evolution of natural GHGs sources and sinks in a world with negative emissions
• Improved understanding of the risk of land/ocean CO₂ release when atmospheric CO₂ decreases
• Assessment of CDR strategies (efficacy, side effects, etc.).

Working Group:

Contact: Narelle van der Wel - This email address is being protected from spambots. You need JavaScript enabled to view it.

Last Updated: 22 October 2025