Modelling assumptions rather than peak warming determine CO 2 removal
needs in 1.5°C pathways
Greenhouse gas emission pathways that are aligned with the goals of the
Paris Agreement generally deploy some kind of carbon dioxide removal,
but the scale of deployment varies greatly between different pathways.
In particular, pathways associated with limiting warming to 1.5°C are
often linked to large scale deployment of carbon removal raising
questions with regard to their plausibility and sustainability. However,
the categorization applied in the Special Report on Global Warming of
1.5°C (SR15) of the Intergovernmental Panel on Climate Change (IPCC), on
which these assessments are based, group together emission pathways with
very different long-term assumptions. Here I show that the scale of CDR
deployed depends much less on peak warming, and therefore the chance to
limit warming to 1.5°C, than on the long-term assumptions in emission
scenarios. Limiting warming to 1.5°C might thus depend less on large
scale CDR deployment than often assumed.