How did you get to school today? Did you drive or ride in a car? Did you take a bus? Perhaps you walked or rode a bicycle? All of these ways of getting to school take energy in one form or another, but does the source of energy matter to us, or our community, or our world?
If you drove in a car, the energy came from fossil fuels, which are from deposits of carbon from organisms that lived millions of years ago. On the other hand, if you walked or rode a bike, the energy came from food you’ve eaten. The combustion of fossil fuels such as gasoline have a lot in common with the respiration reactions that take place while digesting food. Both processes release energy and both produce carbon dioxide gas. If the processes are so similar, does it matter which mode you choose to get to school?