How are the second law of thermodynamics and pollution related?

Thermodynamics can tell us how efficient we can make our internal combustion engines. Since internal combustion engines are notorious for wasting heat and not harnessing all of the power, we find that electric engines which do not rely on heat to run can often be more efficient. An internal combustion engine that harnesses 100% of the energy available in gasoline is impossible to build. So, by looking to other technologies, we can reduce the amount of pollution we produce.