Did You Know?
For every pound of gasoline your car burns, about three pounds of CO2 come out the tailpipe. So if your car gets 20 miles per gallon, you are emitting about a pound of CO2 per mile.
(For every kilo of petrol your car burns, about three kilos of CO2 come out the tailpipe. So if your car gets 8.5 km per liter, you are emitting about a quarter of a kilogram per kilometer.)
How can the amount of CO2 that comes out be three times the amount of gas that goes in? It's because of the oxygen. Your car uses a lot of O2 to burn that pound of gasoline, and some of that oxygen becomes part of the CO2 emitted. You can review the math here.
So that trip to the store to buy a loaf of bread, bag of dog food, quart of milk or bottle of wine probably put a pound or more of CO2 into the atmosphere. That is likely as much as all the CO2 emitted by all the processes involved in growing, manufacturing and packaging that product, and transporting it to your local store.
That is what causes global warming.