Bummer: Journalist Gwynne Dyer suggests that trace amounts of CO2 may cause "mass death and possibly civilisational collapse by the end of the century"

Gwynne Dyer: Fuel companies' carbon bubble greater threat than GFC - Business - NZ Herald News

The other option is that no controls are imposed on burning fossil fuels, and the carbon bubble does not burst until the warming breaks through the two-degree limit and triggers the natural feedbacks that will carry us inexorably up to +6 degrees C. That implies mass death and possibly civilisational collapse by the end of the century, but the fossil fuel reserves will retain their assumed value for the meantime and there will be no financial crash.