Environmental Engineering Reference
In-Depth Information
problems are plaguing China. In Datong, known as the “City of Coal,” the air pollution on some winter
days is so bad that “even during the daytime, people drive with their lights on.”
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Stories of rampant smog in Chinese cities bring fears that the situation will inevitably get worse there
and in any other country that industrializes. Fortunately, our experience in the United States illustrates that
things can progressively get better.
Here again is a graph of the air pollution trends in the United States over the last half century. In the im-
age are total emissions of what the EPA classifies as six major pollutants that can come from fossil fuels.
Notice the dramatic downward trend in emissions—even though we were using more fossil fuel than ever.
Figure 7.1: Decline in U.S. Air Pollution
Source: U.S. EPA National Emissions Inventory Air Pollutant Emissions Trends Data
How was this achieved? Above all, by using antipollution
technology
to get as many of the positive
effects of fossil fuels and as few of the negative effects as possible.
I like to think about risks and side effects this way. When we are using a technology, we are transform-
ing our environment to meet our needs, to achieve a positive effect. But that transformation can accident-
ally or inevitably lead to an undesired effect—a power plant exploding or some type of molecule that, in
