Emission Reduction: Several pounds of CO2 over the course of a year. The extra gas used for your running the air conditioner on your vehicle does account for a slight increase in emissions. For each gallon of gas a vehicle burns, it is emitting about 20 pounds of carbon dioxide. While the emissions savings in shutting off your air-conditioner is not a whole lot, I personally believe that every bit counts. In order to follow this tip, you simply turn off your air conditioner, somewhere around five to ten minutes before reaching your destination. Leave your fan on if you like, as the charge from your air-conditioner will hold for a few minutes allowing cool air to continue to circulate. You will reduce emissions, save gas, and become more acclimated to the outside temperatures before you exit your vehicle. Talk about a win-win-win.