Coal is Incurably Filthy

Coal Mines
Strip Mining
Poisons
Global Warming
Political Problems

Clean dot Org

They're right about coal, but wrong about wind turbines

Deep Mining

We know that coal miners die suddenly in pit disasters, and that they get sick and die slowly from the conditions in the mines themselves. Besides that, sometimes a coal mine or the collapse of the worked-out mine interferes with an aquifer, and quite a lot of the underground pollution does not stay bottled up underground.
But strip mining is probably worse.

Strip Mining

If the coal seam is shallow, huge earth-moving machines can be used to strip the fertile land from above the precious black stuff, and then those or more specialized machines can cheaply move the coal in the seam. The miners don't get as sick, and perhaps their exposure to deadly 'accidents' is reduced, but the result is a more obvious environmental eyesore than the deep coal mines.

It is now the practice to blast whole hillsides and hilltops into the adjacent valleys, ruining both, for the sake of "the USA's cheapest fuel"
Obviously, once you've acquired the coal by these means, you've forfeited the right to call it 'clean', no matter how you consume it.

Poisonous Oxides, Acid Rain

The figures for all fossil fuels in 2006, according to an EIA table,
in thousands of metric tonnes, are:

Carbon Dioxide (CO2)	2,459,800
Sulfur Dioxide (SO2)	9,524
Nitrogen Oxides (NOx)	3,799

Now it is an easily observable fact that the operators of coal-fired power plants resist laws that are designed to prevent the poisonous gases in that list from being emitted into the atmosphere. Such measures cut into the profits of the operating companies. It is probable that coal would seem a much more expensive way to generate electricity than nuclear, if such a plant was required to lock up all of its carcinogen emissions as stringently, measured by the total carcinogenic effect, as a nuclear plant's waste.

These problems are much worse, when you consider the particulates going up the exhaust flues. The thorium and uranium oxides in a year's worth of coal burning by a one gigawatt plant are enough that they exceed in radioactivity the amount that would get a nuclear plant shut down. Even although, in fact, the much greater quantity of lung-irritating other fine dust is a much greater health threat than the radioactivity.

Carbon Dioxide Sequestration

Now we come to the 2.5 thousand million metric tonnes of carbon dioxide. Congress intends to spend a thousand million dollars on ways to sequester it.

"CCS" (Carbon Capture and Storage) projects will be capturing and storing 2.67 times as much oxygen, by weight, as carbon. It would be more correct to call the technology Oxygen Capture and Storage (OCS)!
At present rates of CO₂ production, we would run out of oxygen in less than a million years. That seems like a long time, but it's the same order of magnitude as the existence of the genus homo.

Carbon dioxide is a gas, which has to be compressed by a factor of a thousand to reach a density comparable with water. Compressing a gas costs energy, so you'll have to burn more fuel per gigawatt-hour of output electricity. Carbon dioxide does not "decay" like radioactive waste. You have to bury it forever. Compared with nuclear waste, per unit of energy -- say per gigawatt-year -- the mass, let alone the volume, of carbon dioxide produced is millions of times bigger. And it leaks more easily, and once started, probably more catastrophically.

The idea of "sequestering" gigatons of carbon dioxide is surely far less attainable than the disposing of mere kilotons of nuclear waste.

A kiloton is a thousand tons
A gigaton is a thousand million tons.