What is a secondary carbon footprint?

How to cut your secondary carbon footprint.

If you want to reduce your secondary carbon footprint (in other words the carbon footprint caused by the products you buy rather than the carbon footprint caused by heating your home or driving your car) then you need to start buying products with a zero-carbon footprint, or at least ones with the lowest possible carbon footprint that still get the job done for you. 

The secondary footprint comes in two parts: 

  • Part 1 is the carbon footprint of making, selling and delivering the product to you, and
  • Part 2 is the carbon footprint of using the product over its lifetime

You may think that part 2 is so small as to be ignored. Surely the biggest carbon footprint is in making the product, right? Sometimes yes, but often no. For instance, building a house is expensive and it creates a high carbon footprint from making concrete for the foundation, glass for the windows and copper for the wiring. Building scientists have estimated that the embodied carbon footprint of a house (i.e., how much carbon dioxide is emitted by building the house) is approximately equal to the carbon footprint caused by heating and cooling the house over its lifetime. At the other end of the spectrum, scientists have estimated that the carbon footprint caused by washing and drying a T-shirt over its lifetime is approximately equal to that of making the T-shirt. What we really care about is the lifetime carbon footprint.

There are very few products today that have a zero-carbon footprint. Zero Carbon LLC has introduced one, a T-shirt with a lifetime carbon footprint of zero. Since everyone needs T-shirts, buying one of these instead of buying a “fast-fashion” T-shirt is a great way to reduce your secondary carbon footprint. However, the first priority is to cut your primary carbon footprint and the best way to do that is to implement the fab four on your house. I.e., install 12” of fiberglass insulation in your attic and in the ceiling of your basement, replace your AC units with heat pumps, install single or double-glazed windows with triple-glazed windows when you are replacing your windows and install solar panels on your roof. 

You can see the Zero Carbon™ T-shirt by clicking here