At some point we WILL stop burning fossil fuels simply because they are a limited resource.
You can debate when they will run out or if we will simply stop using them first (either due to technology making them obsolete or concern over the environmental effects giving us little choice even without an alternative).
Having done an awful lot of research into the subject, my personal expectation is that for oil we're damn close to peak production right now. I expect that to occur sometime this decade. Others differ but few put the date more than 25 years into the future and most agree it will be before 2020. In terms of time to prepare etc that's as good as being right now...
I would then expect oil production to have fallen to the point of being a trivial source of energy (compared to today) by 2075 and by 2100 it's likely to be pretty much over to the point that a child born 100 years from now will have trouble believing that oil was ever a major industry. Crude oil then will be like whale oil now - you know it exists but who on ASF personally buys whale oil? Or has EVER seen the stuff? Not many.
Gas isn't too much better. A peak in production sometime around 2030 - 2040 is my best guess and most seem to come up with similar dates. Some 2030, others 2050 but either way it's well within the lifetime of a child born today. With declining discovery and rapidly increasing production, espcially once it becomes the replacement for declining oil supply, the notion that "Australia has 100 years supply" will change awfully quickly. Indeed the plan to export 70%+ of our reserves has already changed the math rather drastically on that one.
Factor in population growth and demand from China etc and per capita oil / gas availability in developed countries basically falls of a cliff. It becomes far more limited than most expect and does so rather quickly. We're talking about an 80% per capita fall in oil supply simply through China etc industrialising to Western levels. And that's without a fall in production.
As for coal, there's still plenty but again it is ultimately a limited resource. Factor in a few % annual growth in demand and the 200 year supply ends up being a production peak sometime later this century. And that's if we're brave enough to keep using the stuff (or find a way to keep the emissions out of the air).
So in 200 years time greenhouse gas emissions are near certain to be a LOT lower than today. That's the good bit. The downside is that emissions of particles etc causing global dimming will also be very much lower and that already emitted falls back to the ground pretty quickly. So no real effect from global dimming in 2200, but most of the greenhouse gases will still be in the air. We get the warming without the cooling - that's when the real trouble hits I would expect.
For that matter, we don't really know the full extent of the effects from greenhouse gases already emitted. Not only does it take time to have an impact but we still have the cooling effect from particles, sulphur dioxide etc. Stop burning coal, oil and gas literally today and there's still quite a bit of global warming "baked in the cake" that we're yet to feel the effects of.
Bottom line - we're going to have to live with warming no matter what we do now. All that we can change is the extent of it. And we're going to have to drastically cut the use of oil in little more than a generation with gas not far behind. We simply have no idea how to find enough of the stuff, even if it does exist somewhere, to carry on as we are.
Personally, I think we'll end up pumping emissions from coal-fired power plants underground and the nuclear industry will greatly expand. There just isn't enough time for renewables to basically replace oil and gas whilst also doing away with coal and nuclear. But that doesn't mean we shouldn't be developing renewables - to the contrary. It will take time to scale up and apply to mobile applications (aviation being by far the most difficult) and time is something we don't have too much of when it comes to energy supply.