Carbon footprints

The problem:
Assessing the “carbon footprints” of activities and developing and assessing alternatives to help reduce them is easier said than done. For example, ~500 colleges and ~900 cities have signed low-carbon pledges, but how anyone will know if the goals have been met is unclear.  The carbon footprints of even simple actions vary as a result of geographical, technological, and social factors.  While the literature on comparative analysis of the GHG emissions of technologies advances, users of such research typically do not have the information necessary to understand the assumptions that cause footprints to be higher or lower.

The WRI/WBCSD GHG protocol and British PAS 2050 are inspiring a movement from organizational to product level footprints (e.g., for carbon labeling).  These protocols encourage firms to report emissions from direct activities and also purchased electricity (termed Scope 1 and 2), even though research suggests total footprints are generally three times higher when other upstream activities (Scope 3) are included.  There is an urgent need for frameworks that:

  1. estimate and represent the uncertain life cycle GHG emissions of existing activities and proposed low-carbon alternatives;
  2. present technical guidance on how to minimize the uncertainty of the estimates as well as the decisions; and
  3. present those results and their associated uncertainties in formats that are clear and easy to understand.

The research:
Scott Matthews and colleagues have been collaborating with GHG protocol organizations (e.g., WRI) as well as firms that both use and provide carbon accounting services (e.g., IBM and SAP) to study the ways to improve carbon accounting at the firm and product levels. Under the proposed Center, we plan research in three areas:

  1. Frameworks for accounting for footprints of activities. We propose to build next-generation carbon footprint estimators (not calculators) that capture the major sources of emissions for their context, clearly identifying the nature and extent of uncertainty in different parts of the estimate.  For example we could show whether the largest uncertainty in one’s transportation footprint is associated with the number of miles driven or the production location of biofuel. This framework will also aid in developing explicit life cycle methods to inform decision makers in setting standards and using the tools in LCFS’s and various sustainability certification programs;
  2. Reporting the uncertainties. We will conduct empirical studies of how best to report consumer and organizational footprints to support individual or organizational decision making using psychometric methods and leveraging web-based technologies and advances in human-computer interaction to visualize uncertainty. We will construct paradigms of product labeling schemes, such as an expansion of the Energy STAR program to include life cycle effects, and evaluate implications of data and methodological uncertainty on label integrity and lowered emissions; and
  3. Frameworks for personal and regional decision-making. We will develop web-based methods of determining and communicating the economic and environmental constraints of climate policy for personal and regional strategies. For example, in support of low carbon cities, LED street lights may reduce GHGs at a cost of $10-30/ton, but could require tens of millions in scarce capital.  Thus, a portfolio of implementable alternatives may need to focus on a mix of technologies with low upfront cost and “second best” cost-effectiveness.  It may also dictate small-scale, indirect investments where cities give partial tax credits for residents to buy 100 hybrid cars rather than buying 10 hybrid cars for the city fleet.  This same underlying framework can be used to help consumers or college campuses decide the most effective low-carbon actions required to reduce their footprint at minimum cost.

Members of our team have been leaders in making web-based life cycle assessment tools.  The national EIO-LCA tool has had millions of uses in the past decade, and has been extended to regional and international assessment (see

The decision makers:
ASWPa, EPRI, EPA/ENERGY STAR, IRGC, NRDC, Ontario MoE, SAP, SustPgh, Toyota, Vancouver, WRI.