No Fossil Fuel Burning At All
The real requirement, if we are to avoid runaway global warming, is probably 80% by 2030 and almost no burning whatever of fossil fuels (coal, gas and oil) by 2050.
~ Gwynne Dyer (1943-04-17 age:75) 2008-12-08 based on 18 months of 70 interviews in a dozen countries.