The way I look at this:

1) Science has known about the risk of too much CO2 in the atmosphere for over 100 years.
2) We all were warned, publicly, that this risk was upon us over 30 years ago (James Hansen testimony to Congress).
3) Most of us didn't pay much attention.
4) The issue became political when 1 of our 2 major parties decided to reject the science. 

1/2

Report: The world’s most critical climate target is still within reach | Grist
https://grist.org/energy/iea-report-1-5c-within-reach/