While âoecarbon footprintâ has become part of the popular lexicon, nobody knows what the concept means in specific, real-world circumstances. In other words, there is no consensus on how to measure or quantify a carbon footprint. Despite the growing number of basic online calculators and institutional protocols, the reality is that not even the units of measurement are clear. As a result, it seems unfair to beat up Dell for what appears to be a well-intended effort to reduce its environmental impact. The real culprit is the metaphor âoeCarbon Footprint.â The term is rooted in the language of Ecological Footprinting. The Global Footprint Network interprets the term as a measure of the âoebiocapacity required to sequester (through photosynthesis) the carbon dioxide (CO2) emissions from fossil fuel combustion.â In other words, how much land would it take to grow enough plants to process the carbon emissions naturally. In this context, the basic metric for measuring carbon footprints is land area. Because CO2 is physically measured in mass units (tons), this area-based approach would require the conversion from a mass unit into an area unit (hectares), which would have to be based on a variety of assumptions that increase the uncertainties and errors associated with a particular footprint estimate. To make matters worse, academic and institutional definitions have endorsed a wide range of methodologies raning from direct CO2 emissions to full life-cycle greenhouse gas emissions assessments. The bottom line is that the metaphor was a poor choice to begin with. Complete comment here . . . http://cleantechlawandbusiness.com/cleanbeta/index.php/1959/dell-inc-has-proclaimed-itself-carbon-neutral-do-you-agree/