Part of the problem is that the IPCC in most of the more conservative scenarios were assuming humanity acted on climate change and limited CO2e emissions or tha

Part of the problem is that the IPCC in most of the more conservative scenarios were assuming humanity acted on climate change and limited CO2e emissions or that their growth at least tapered off (they did for a while after the 2008 crises). I can predict that if you save $1 every year that you'll have $10 in 10 years, but if you don't save that $1 then the prediction isn't wrong even though it doesn't reflect reality.