This is what the SSPs assume, by design.
To believe #RCP85 you need
* World that prioritises fossil fuels
* Zero climate policy to 2100
* Zero climate impacts to 2100
1/
link.springer.com/article/10.100…
RCP1.9 or RCP2.6 (1.5°C or 2°C) generally use loads of Bioenergy with CCS, but it is assumed that a 2°C world has no climate impacts on that bioenergy (or food & agriculture, or forestry).
2/
In practice, mitigation pathways don't consider feedbacks from climate impacts (in the vast majority of studies).
3/
4/4