GM Spokesperson admits energy to charge cars comes from coal

We’ve made strides in reducing the visible air pollution; the results can be seen by all. How can ones eyes see emitted gasses which are invisible; can changes in the emissions of these pollutants been seen by all? If we can’t see the changes we’ll have to trust the data produced by instruments designed to measure what we can see, like the gauges that measure how much is in our fuel tanks.