I received a letter from the Sierra Club about “pollution” and global warming. As I remember going through Earth Day in 1970—the first—a lot has changed, and I find it necessary to define “pollution.”

Pollution is primarily something that is toxic, such as lead or mercury, that has harmful effects even in small amounts. Or it could be something that is harmful in large amounts, such as the ingredients in laundry detergents in the 1960s that were causing excessive growth of algae in rivers and streams.

And now we come to the irony of Earth Day 1970—the biggest pollution was smoke, exhaust from internal-combustion engines. What was considered nonpolluting was … carbon dioxide! That’s right, the concern was unburned hydrocarbons, which were causing smog. What was desired was the catalytic converter, which would burn the exhaust completely through. Back then, CO2 was not considered pollution.

If CO2 is pollution, then by logic, we must destroy all animals, including ourselves. After all, animals produce carbon dioxide.

We need a little clarity. The problem facing us is fossil fuels, not carbon dioxide. Fossil fuels increase the amount of carbon in the atmosphere to levels not seen in tens of millions of years. With the exception of China and coal, energy from fossil fuels has been produced in significant amounts only for a few centuries, beginning with coal and then later petroleum and gas.

I believe it is impossible to predict what would happen if excessive amounts of carbon are released. We do know in geologic eras past the atmosphere was very different.

As we have only recently used fossil fuels in large amounts, I feel it will be easy to change our ways if need be. If we had to, in a short amount of time, America could produce electricity from sources other than fossil fuel. Already, people are beginning to buy hybrid automobiles, which is the first step.

Daniel Barker
Lakeland, Fla.