“Do the Tier 1 and 2 estimates provide reasonable guidance?”
“Nearly two-thirds of all economic sectors providign goods and services (…) would have less than 25% of their total carbon footprint represented by Tiers 1 and 2.”
These are just two statements from a recently published report. “The Importance of Carbon Footprint Estimation Boundaries” was published by H. Scott Matthews et.al. from the Carnegie Mellon University in the Environmental Science&Technology Viewpoint. I read about it on ClimateBiz.
The survey analyzed existing methodologies for calculating carbon footprints, which are mainly focusing on so called Tier 1 and 2 emissions. These are emissions from the direct energy-consumption and indirect emissions of purchased electricity and steam. This view makes definetly sense for e.g. power plants. But these are already under investigation through the Kyoto-protocol or similar guidelins.
The researchers porpose to extend the existing three Tiers yet another fourth tier. This Tier 4 should include the total life-cycle emissins for production (reflected in Tier 3) plus delivery, use and end-of-live.
The extension makes from my point of view and my daily experience with customers really sense since most companies which would like to contribut to voluntary climate protection can really focus on their main emission sources. I call those sources the sensitive positions in a balance or carbon footprint. Many times only a few sensitive positions determine the outcome considerably.
This study is the second recommendation after the statement of the European Commission (EPLCA) which clearly advise to get the whole picture by apply a life-cycle approach. And for sure there will be more to come soon from a well known international body – trust me.