I am pleased to see someone else argue optimistically that BAU has changed dramatically. Too many around here believe in climate catastrophe is imminent.
Being realistic is not equivalent to expecting climate catastrophe. I, for one, am quite cynical about politicians, but at the same time expect humanity to completely give up fossil in due time. I expect no catastrophe whatsoever. But I expect decades of warming still, because going to zero carbon is a very long process.
eg:
- 95% of cars sold in 2021 are using gas/diesel. Those cars will still be on the roads in 2050 (in India, Africa, etc).
- many industrial processes are hard to decarbonise
- gas turbines are needed to counterbalance volatile solar/wind
- newly built coal plants will NOT be closed for a long time (at least a decade) due to sunk costs
Will emissions start to go down some time in the 20s? Hopefully yes (but considering that oil will at least be stable, gas will go up, coal down and industrial and agri likely up that is not sure at all). Shall we hit zero by 2030-40? Absolutely not. Not even by 2050.
2015-20 warmed +0,29 C vs 2005-10. Considering Arctic feedback, it is hard to see how that will not be more in the next decade, since emissions are higher now than 10 yrs ago. We are already +1,2 C above pre industrial. This means that by 2030 we shall hit at least +1,5 C. If you are optimistic then you can argue that warming will slow after this, so maybe +0,2 C and +0,15 C and +0,1 C the following decades. This still means that we will reach around +2 C by 2060 - provided that there are no sudden climate impacts.
I don't think this will make the Earth unlivable. I even think that it will be positive agriculturally for many NH midlatitude countries as they will warm by another 1,5-2 C.