5. Ground Level Ozone - Burning Fossil Fuels
Finally, burning fossil fuels also contributes to the formation of ground-level ozone, or smog. Ozone is O3, so NO3 breaks down into nitrogen and ozone, with the latter being bad for the health of humans and other animals. Thus, while nitrogen, carbon dioxide and pH have optimum ranges, ozone has an optimum /location/ within the biosphere: namely in the upper atmosphere or stratosphere, where it protects us from harmful ultraviolet radiation. In the lower atmosphere, or troposphere, it becomes a pollutant.
Fossil fuels – coal, oil and natural gas — currently provide more than 85% of all the energy consumed in the United States, nearly two-thirds of our electricity,
and virtually all of our transportation fuels.
On both the sustainability front, and the ecological destructiveness front-the two ecological criteria used to judge the appropriateness of technologies-fossil fuels fare very badly. They are not only being rapidly depleted, but are threatening the biosphere in the process of being used. The sooner we find sustainable, emission-free replacements for them, the better off both humanity, and the planet Earth, shall be.