Scenarios are not predictions of the future: they are tools to explore the space of possible decisions and their consequences. Every pathway to 1.5°C (and most 2°C pathways) produced by Integrated Assessment Models (IAMs) now relies on some volume of carbon dioxide removal (CDR) – whether through afforestation and reforestation, bioenergy with carbon capture and storage (BECCS), direct air capture (DAC), enhanced weathering, or ocean-based approaches. Yet the amount, timing, technology mix, and geographical distribution of CDR deployment differ enormously across models and scenarios, with direct consequences for land use, biodiversity, water, food security, and the rights of indigenous and local communities.

This winter school unpacks how CDR enters IAMs and shapes the scenario space used by the IPCC and climate policy more broadly. Sessions combine lectures from modelling and policy experts, hands-on exercises with scenario data, and guided discussion of recent discussions about equity of CDR burden-sharing, feasibility and sustainability limits, and overshoot risk.