In three years giving this talk I have never encountered the question, “What about the air pollution from burning fossil fuels?” This is by far the best question and possibly the most difficult question I have ever encountered. It required further research to produce a decent response.
You can point out alternative energy sources to fossil fuels (coal, oil, and natural gas) are solar and wind energy that have to occupy vast land areas and consume great amounts of materials because they have such low energy densities compared to fossil fuels. Massive amounts of steel, concrete, and exotic materials are required in their construction which generate big pollution problems of their own. Regions of China are polluted producing rare earth metals required in wind turbines. Metals and cement industries are more polluting than power generation. Due to limited lifetimes of these plants of the order of twenty five years, they have to be replaced continuously.
Due to intermittent operation of these plants, standby natural gas-fired turbines, that do not operate at peak efficiency, are required to keep continuous power generation. Wind turbines have their own peculiar problems of producing obnoxious noises and killing large numbers of valuable birds such as bats, condors, and eagles. In addition, these energy sources produce electricity far more expensive than fossil-fueled sources.
However, this is not the answer to the question about air pollution from fossil fuels. This is substituting the answer to a different question that is frequently employed by those trying to salvage an argument.
Burning any fossil fuel produces carbon dioxide–coal producing the most for a given amount of energy produced. Coal produces about 220 pounds of carbon dioxide per million British Thermal Units(BTU); while natural gas or oil produce about 140 pounds per million BTU.
Those promoting increased atmospheric carbon dioxide is causing catastrophic global warming maintain carbon dioxide is pollution. Those who say the greenhouse effect of burning fossil fuels is negligible, maintain carbon dioxide is not a pollutant; but an airborne fertilizer provided by nature that increases crop yields so we can feed our 7 billion people.
Natural gas as an energy source is pretty clean and essentially only produces water vapor and carbon dioxide upon combustion. Coal and oil have impurities such as sulfur and mercury that produce additional combustion products besides carbon dioxide and water vapor. In addition, high temperatures and pressures, like internal combustion engines, of burning fossil fuels can produce nitrogen oxides and ozone.
If we examine the earth’s atmosphere without the presence of humans, it is noted there is mercury, sulfur dioxide, ozone, and nitrogen oxides that is due to natural events such as off-gassing from the oceans, forest fires, volcanic eruptions, lightening, and other catastrophic eruptions that are common natural events. Seventy percent of world’s pollution from mercury is due to natural events.
Until the end of WWII, coal was the United States’ major energy resource. Coal was used for producing electricity, heating homes and buildings, and operating trains with little concern about combustion gases. Today coal is only used for electricity production out of these previous uses and the combustion gases are controlled with electrostatic precipitators and scrubbers that essentially remove all pollutants.
The use of oil for transportation by cars and trucks produced pollutants of carbon monoxide, ozone, and nitrogen oxides. Modern technology using catalytic converters, fuel injection with computer-controlled fuel-air mixtures has reduced transportation pollution from individual cars to less than one percent the level of fifty years ago.
Examining the world’s atmosphere and comparing it to a world free of humans may show some pollution. Most of this pollution is due to countries that do not have strict anti-pollution laws of the United States–see China as an example.
The little air pollution we may have has to be weighed by the benefits of using fossil fuels. How many tons of manure has been displaced by cars? How filthy would our water be without use of pumps that transport water long distances and clean it via sewage treatment plants? How many people would die of food poisoning if we did not have efficient means of transporting food, cooking, and refrigeration?
Human lifespan in the United States has advanced every year for the past 110 years chiefly due to our abundant fossil fuels and their effective use. The vast fossil fuel resources within the United States boundaries can insure centuries of improved health and prosperity.