10.2 Carbon footprint labeling how to have high data quality and to maximize utilization

Jannick H. Schmidt , 2.-0 LCA consultants, Aalborg, Denmark
Bo P. Weidema , ecoinvent Centre, St. Gallen, Switzerland
Introduction
The issue of carbon footprint and product labeling is hot on the environmental agenda. The pros and cons are vast. The pros are obvious; it includes a broad variety of opportunities for actions and intensives which by use of better information hopefully will lead to better decisions for the climate. The cons include statements such as it is overwhelming resource demand in terms of costs and time, and that it can be questioned if it is possible to make meaningful carbon footprint labels.

In this presentation, firstly we will demonstrate that GHG emissions for carbon footprint labels can easily be calculated using a hybrid approach for life cycles assessment (LCA) implying a relatively low degree of uncertainty. Secondly, we will present some of the potential future uses of carbon footprint.

Hybrid LCA and calculation of GHG emissions
The traditional approach for calculating GHG emissions related to products and services is the so-called process-based LCA, where a number of processes are identified and included as part of the product system. The processes are normally linked via physical flows (based on engineering knowledge). A major problem of this approach is that a broad variety of inputs are usually excluded from the product system, e.g. business travelling, marketing, consultancy, accounting, legal assistance, education, buildings, machinery etc. This is acknowledged in the ISO 14044 and 14044 as well as in the PAS2050, but neither of them provides a solution to the problem.

To overcome the problems of cut-off rules, input-output-LCA (IO-LCA) can be used. IO-LCA is based on a nation’s total economic transactions combined with total emissions accounts (NAMEAs). Therefore, such data do by definition include all above mentioned inputs which are typically excluded from the calculation of GHG emissions. It is not unusual that GHG results obtained from IO-LCA is 50-150% higher than those of process-LCAs. This is due to the difference in completeness in data. The main problem of IO-LCA is that it typically does not include more than 100-500 product categories, and that many products belong to inhomogeneous product categories in the IO-table. Also the reference flow in IO-LCA is typically in monetary units which may make the interpretation difficult. However, some IO-tables exist in hybrid units (e.g. physical products are measured in mass unit, energy is measured in energy unit, and service products are measured in monetary unit).

If the starting point of the calculation of GHG emissions is IO-data, the most important inputs, such as energy and feedstocks can be replaced by process-based LCA data. This approach is referred to as hybrid LCA and it benefits of the completeness in data from the IO-LCA and the detailed modeling in process-LCA. An iterative approach can be applied where the importance of inputs are evaluated, and where the most important inputs, for which more precise data are available, are replaced. By doing so, for each iteration the LCA will be associated with less uncertainty and it will be more resource demanding (costs and time). Thus it is possible to define an acceptable/optimal level of uncertainty depending on the benefits from the use of the carbon footprint label.

Uses of carbon footprint labels
Carbon footprints have many potential applications. The most important uses are listed below:

  1. Product information to the users
  2. Carbon footprint labels on substitutable/competing products can lead to more climate friendly choices
  3. If only some of the substitutable/competing products have a label, the remaining products can be labeled with a residual label (residual = all products minus products having a label). This would create an incentive for non-labeled suppliers to label their products and to reduce GHG emissions. Then the process become self-perpetuating
  4. The most widely used LCA software is SimaPro (www.pre.nl) which comes with the World’s most comprehensive and well-documented LCA-database; ecoinvent (www.ecoinvent.ch). Having a carbon footprint label, this can be included with brand and company name in the ecoinvent database. This may further strengthen the above mentioned self-perpetuating effect because the residual may become worse for those who are not providing their own data
  5. Carbon footprint labels can be included in the bar code of a product which can serve several purposes for the individual customer, e.g. having a total footprint for all purchases, comparing this to alternatives or to other similar customers, setting and monitoring personal targets, all of which may be supported by web-based tools.

It can be concluded that the obstacles on carbon footprint has been overcome; the calculation of GHG emissions from products can be done with relatively little resource input (costs and time), and with high completeness in data and with relatively low level of uncertainty. By labeling products we will have much better information on the relationship between our actions and our impact on the climate. Such information can by used for better climate solutions by politicians, NGOs, scientists, and actors within production, trade, and consumption.