Purchasing and Negotiation Training

Robert Menard, Certified Purchasing Professional, Certified Professional Purchasing Consultant

Editor’s note:this is the fifth of eight chapter previews of the new workbook and manual, Green Purchasing and Sustainability, that will be available to order in July 2011.  To see all chapter previews, click here. 

Carbon Foot Print

 This is probably the most well known term in sustainability.  It is at once the most prized and reviled status, depending upon viewpoint. It is also difficult to distinguish truth from fiction; i.e. one can find carbon foot print calculators on multiple web sites and compute nearly as many different answers.  As with many other sustainability concepts that we have studied, there is no universal definition.  Furthermore, the many sciences and political combatants involved combine to generate so many divergent view points as to make “carbon footprint” an understandable yet vague term. 

There are many competing definitions that are both precise and accurate, but are so colored by the competing parties that they are useless in general application.  We also will not venture deeply into the murky world of “carbon offsets”, a subject of many greenwashing charges.  As has been the habit in many controversies in this online course, we homogenize the available research data to arrive at the best, most useful average interpretation. 

The table below was compiled from a variety of sources to compare carbon emissions generated by eight fuels.  The reader will recall a similar table in Chapter Two that compared Btu/$ for many of these same fuels.  This one shows the carbon-dioxide (CO₂ liberated for each equivalent unit of fuel used to create electric energy. The physics is complicated but the simplicity of the over all pattern is obvious.  Some fuels, shown here in descending order, have a greater carbon foot print than others.  The emissions are in grams instead of pounds of CO₂ equivalents per kWh because at 454 grams per pound, the values at the lower end of the scale would be infinitesimally small.  The order of magnitude is more important for our purposes than actual values.