Replacing your motor vehicle with a human powered bicycle will actually cause more pollution! Your vehicle has the latest in pollution controls, you have none. I dare say that once you start riding a bicycle you will start to pollute more than your car. As you start exerting yourself your body will require more food and water. it will also start exuding body fluids and gas with no pollution controls. Consequently you will purchase more food requiring the corporate owned farms to produce more food. Producing more food requires even more chemicals be added to the soil and pesticides applied. All this stuff must be transported using petroleum fuels as well. More people riding bikes or walking to work would be an environmental disaster!