The World in 2050_ Four Forces Shaping Civilization's Northern Future - Laurence C. Smith [42]
It’s enough to make you wish there was more oil. Coal is the dirtiest and most environmentally damaging fuel on Earth. Entire mountaintops are leveled to obtain it. Coal mining pollutes water and devastates the landscape, covering it with toxic slurry pools and leaving behind acidic, eroding deposits upon which nothing will grow. I studied one of these places for my rather traumatizing master’s thesis. An hour’s fieldwork would leave me covered in black grime, hands and clothing stained orange from an acidic creek full of chemical leachate.176 Coal mining also releases trapped methane, a powerful greenhouse gas and even more powerful explosive inside subterranean mines. Several thousand coal miners are killed each year in China.
Coal is worse than oil and much worse than natural gas when it comes to emissions of greenhouse gas, because its carbon content is the highest of all fossil fuels. To produce an equivalent amount of useful energy, burned coal unleashes roughly twice as much carbon dioxide as burned natural gas. It also releases a host of irritating or toxic air pollutants, including sulfur dioxide (SO2), nitrogen oxides (NO and NO2), particulates, and mercury. It makes acid rain. If converted to a liquid, it releases 150% more carbon dioxide than oil fuels. To people hoping to bring our escalating release of greenhouse gases to the atmosphere under control, coal is Public Enemy Number One.
As my University of California colleague Catherine Gautier writes, “Were it not for its environmental impact, coal would be the obvious choice to replacing oil.”177 From a geological perspective, there will be no scarcity of the stuff anytime before 2100.178 And therein is the problem: From nearly all model projections, coal is slated to replace oil. By the year 2030 its consumption in the United States is projected to rise nearly 40% over 2010 levels. In China, which already burns twice as much coal as the United States, consumption is projected to nearly double.
Other than banning the stuff, the only thin hope lying between this future and a giant upward lurch in the atmosphere’s greenhouse gas concentrations is something called Carbon Capture and Storage (CCS), often called “clean coal” technology. There’s no such thing as clean coal, but CCS does appear technically possible and, at first blush, alluringly simple: Rather than send carbon dioxide up the smokestacks of coal-burning power plants, use chemical scrubbers to capture it, compress it to a high-pressure liquid, then pipe the liquid someplace else to pump deep underground. Oil companies already use a similar process to force more petroleum out of declining oil fields. Successful pilot demonstrations of CCS technology are under way in Norway, Sweden, and Wyoming, the longest running for more than a decade without mishap.
The main problem with CCS is one of scale, and therefore cost. First, the “capture” process consumes energy itself, requiring significantly bigger plants burning even more coal to generate the same quantity of electricity. Second, a vast network of pipelines is needed to transport staggering volumes of liquid CO2 away from the power plants to suitable burial sites (abandoned oil fields or deep, salty aquifers). The United States alone produces about 1.5 billion tons of CO2 per year from coal-fired power plants. Capturing and storing just 60% of that means burying twenty million barrels of liquid per day—about the same as the country’s entire consumption of oil.179 Small