At the very least the numbers of 99 ppm and 100ppm are measurement of the problem that one is trying to solve. The more typical braindead form of regulation would mandate one specific kind of mitigation regardless of the current level of pollution. While at the same time it is, of course, a pure coincidence that the more polluting company is friends with a politician while the less polluting company that now has to pay for less necessary or unnecessary mitigation is not friends with said politician.
> the numbers of 99 ppm and 100ppm are measurement of the problem that one is trying to solve
Not for air pollution. There the total emissions are of interest, not the rate. Car emissions, for example, are regulated for their rate of emission, not total emissions.
Even there, ppm is a suboptimal (maybe even terrible) measure. If I can find a way to pump additional air through the exhaust (increasing the denominator), I can lower my tailpipe ppm without lowering the rate of emitted pollutant (the numerator).
Of course, there are many ways to reduce the rate (as you mention), and of course, the government has made such modifications illegal.
My proposal is to measure the emission rate, multiply it by the mileage driven in the last year, multiply by the tax rate, and pay the tax to renew the license.
It's not perfect, but it's simple and a far better approximation than the existing brain-dead method. Instead of incentivizing drivers to just pass the test, they are incentivized to minimize the total pollution their driving emits.
In this case, “I” was intended to mean an automotive engineer working to comply with a government ppm-metric-driven regulation, not an end consumer, but my words were definitely ambiguous on that topic.
