A recent report in the academic journal, Science Advances, predicts that in the event that all known reserves of fossil fuels are burnt, average temperatures would be approximately fourteen degrees hotter than they are today after ten thousand years. However, it is possible that this may not happen. As supplies dwindle, the cost of extracting oil and gas from the ground would increase significantly, far beyond the low commodity prices seen in the market today. It is likely that there will come a time when it is simply unprofitable for the energy companies to pay for future extraction, and production would be cut accordingly. However, relying on the market to limit the use of fossil fuel resources is an imperfect solution. We should heed Elizabeth Kolbert's warning to start long-term strategic planning now.
If mankind managed to combust the world’s known conventional deposits of coal, gas, and oil, and then went on to consume all of its “unconventional” ones, like tar-sands oil and shale gas, the result would be emissions on the order of ten trillion tons of carbon. Average global temperatures would soar, and the world would remain steamy for millennia. After ten thousand years, the planet would still be something like fourteen degrees Fahrenheit hotter than it is today. All of the world’s mountain glaciers and the Greenland ice sheet would melt away; Antarctica, too, would eventually become pretty much ice free. Sea levels would rise by hundreds of feet.