The technology advances required to eliminate Fossil Fuels as G7 wantsare not on the horizon.

To call, as the G7 has, for a non fossil fuel world by the end of the century is all very well. But it needs technology advances that are not in the pipeline.

Energy use can be conveniently be divided between that which is competitive between primary energy alternatives and that which is not. Electricity generation is a classic example of the former. You can generate electricity from Coal, Oil, Gas, Wind, Solar, Nuclear, Hydro...etc etc. To have all our electricity from renewable and non carbon resources is technically feasible although, of course, some very large investments would be required to make the switch possible in a world in which energy demand is inextricably rising. 

However much of our primary energy consumption is in the "non competitive" category - mainly all the "Oil specific" use in transport. Here it is neither technically feasible to use anything but oil  or there is a hugely negative economic consequence. Aircraft can only fly on oil and there is no alternative (outside Science Fiction!) to this. Shipping is presently 99% oil reliant. Road transport (Cars and trucks and buses etc) not much less. You can use electricity to move cars (etc.) but until there is a technology breakthrough which gives cost and range parity with petrol/diesel it will not happen to any significant extent.