I think you may be mistaken on ther enot being a lot of coal left:
"According to the widely accepted view, at current production levels proven coal reserves will last 155 years (this according to the World Coal Institute). The US Department of Energy (USDoE) projects annual global coal consumption to grow 2.5 per cent a year through 2030, by which time world consumption will be nearly double that of today."
The article goes on to say that we probably don't have 155 years of coal reserves, but it should still last for some time now, unless the rate of usage sky rockets.
No, my argument would be that in 155 years we'll have better alternative sources of energy. Wind and Solar are already viable alternatives, with time their cost will come down and their efficiency will go up potentially eliminating the need for fossil fuels such as coal.
"According to the widely accepted view, at current production levels proven coal reserves will last 155 years (this according to the World Coal Institute). The US Department of Energy (USDoE) projects annual global coal consumption to grow 2.5 per cent a year through 2030, by which time world consumption will be nearly double that of today."
From: http://www.energybulletin.net/node/29919
The article goes on to say that we probably don't have 155 years of coal reserves, but it should still last for some time now, unless the rate of usage sky rockets.