Today, most major companies publicly report their emissions to CDP, an international corporate emissions platform. As sustainability managers know, corporate emissions come from a variety of sources, which are grouped into “scopes.”
Scope 1 = the emissions from owned or operated assets (for example, the fumes from the tailpipes of a company’s fleet of vehicles)
Scope 2 = the emissions from purchased energy
Scope 3 = the emissions from everything else (suppliers, distributors, product use, etc.)
Needless to say, measuring scope 3 emissions is a big undertaking. But it matters: for many businesses, scope 3 emissions account for more than 70 percent of their carbon footprint. Measuring and managing these emissions can motivate a company to do business with greener suppliers, improve the energy efficiency of its products, and rethink its distribution network — measures that significantly reduce the overall impact on the climate.
Measuring value chain emissions can also earn companies a gold star with investors and stakeholders. CDP scores companies based on climate change-related information collected through its global environmental disclosure system. These scores are then shared with CDP’s large investor network representing more than $100 trillion in assets. Companies earn points toward this score by disclosing emissions from scope 3 categories. Taking responsibility for value chain emissions is also a requirement for joining the Science Based Targets initiative, a growing cohort of companies that are recognized for aligning their emissions-reduction targets with climate science.
Read more at: http://www.ghgprotocol.org/node/469