A science lesson on a carbon footprint

An element is defined as the smallest bit of matter (an atom) that exhibits the properties of the bulk material and cannot be separated into a simpler substance. A compound is defined as any substance formed by the union of two or more elements in a fixed ratio, the union being a chemical bond (which may be either ionic or covalent but I digress). Compounds have physical and chemical properties that are not the same as those of the different elements (or atoms) that they contain (and this is also true for allotropes like diamond, graphite and coal – all consisting of carbon – but again I digress).

In oxygen-breathing organisms, carbon dioxide (CO2) is produced in the body as a result of cellular respiration, wherein vital nutrients are converted into energy in the presence of oxygen (O2) and enzymes, the latter of which catalyzes this “burning” process at around 98.6 degrees F (or 37 degrees C). Animals uptake O2 and thus release CO2; at night chlorophyll-containing plants also uptake O2 and release CO2.

The burning, or combustion, of carbon-containing fuels like coal, oil, gasoline and natural gas in O2, which occurs at a much higher temperature, also produces CO2. Incidentally, with the exception of coal, the other fuels also produce water vapor.

Burning carbon-containing fuels does not produce carbon but in fact produces CO2, and for the sake of simplicity I will assume that the reaction goes to completion and produces only CO2.

So there is no such thing as a “carbon-footprint” (unless of course you are a coal miner who doesn’t change his shoes after leaving work (get it?). So the correct term is “carbon-dioxide” (or CO2) footprint not carbon-footprint – an important distinction from a chemical perspective.

(By the way, please don’t confuse CO2 with carbon monoxide (CO) as they too are two different compounds.)

Quod erat demonstrandum.

CHARLES F. HEIMERDINGER

Edinburg