Carbon Footprints and Life-cycle Assessments — Educational Resources

By Lisa DiCaprio, Conservation Chair, Sierra Club NYC Group

Measuring to reduce is a basic sustainability concept.* Carbon footprints and life-cycle assessments inform sustainable business initiatives, government policies and consumer choices.

CARBON FOOTPRINTS provide the necessary data for developing goals and strategies to reduce emissions from the six Kyoto Protocol greenhouse gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6). We can measure the carbon footprints of products, services, buildings, institutions and organizations, such as universities and companies, cities and even entire countries.** Here, I will focus on product and digital carbon footprints.

The life-cycle carbon footprint of a product measures its carbon emission from the extraction of raw materials through disposal.

The Greenhouse Gas (GHG) Protocol identifies three scopes of emission for a carbon footprint, which is measured in CO2e (carbon dioxide equivalent).

Scope 1: direct emissions from the on-site combustion of fossil fuels for the production of electricity, heating and cooling, and company vehicles.

Scope 2: indirect emissions from purchased electricity and offsite heating and cooling sources, such as steam or chilled water.

Scope 3: relates to upstream and downstream emissions that are not controlled by a company. Sources of upstream (supply chain) emissions include transportation used by suppliers, purchased goods and services, and waste disposal. Downstream (use and disposal) emission sources include transportation and distribution to customers, the processing and use of sold products and the end-of-life disposal or recycling of sold products.


Agricultural and seafood products:
Paper products:
Digital communication and online shopping:
Marijuana Plants:
Concrete and cement:
Outsourcing carbon emissions:
Measuring and reducing your individual carbon footprint:
LIFE-CYCLE ASSESSMENTS (LCA) are more comprehensive than carbon footprints. The LCA of a product analyzes each phase of its life cycle (extraction of raw materials, manufacturing, transport, use and disposal) from the perspective of several environmental and health impacts, such as the consumption of water, energy and minerals, and the pollution of air, water and soil. For example, the LCA of an electronic product considers how its disposal affects public health and the environment. As Amy Lee describes in her May 12, 2019 article on the accumulation of electronic waste, “Electronic Marvels Turn into Dangerous Trash in East Africa,” the toxic materials from discarded computers, televisions, cellphones, and lead acid and lithium batteries are polluting surface and ground water, and soil, including farmland.

Life-cycle assessment methodologies
Vineyards and wineries
  • Napa Green certification for vineyards and wineries in the Napa Valley in California. [Note: The Sierra Club is a Napa Green partner.]
  • Shana Clarke, “Why Some Wineries Are Becoming ‘Certified B Corp’ — and What That Means.” National Public Radio (NPR), May 13, 2019. [Note: B Corp certification is based on five impact areas: customers, workers, community, suppliers and the environment. B Corp companies include Eileen Fisher and Patagonia, mentioned above. For more information, see the Certified B Corporation website.]
Christmas trees
*    For my previous Sierra Atlantic articles on topics relating to this column, such as how to reduce greenhouse gas emissions and conserve natural resources, see

** For example, Local Law 22 (2008), introduced as Int. 0756-2008, mandates the annual inventory and analysis of NYC’s greenhouse gas emissions. At an international level, all signatories to the United Nations Framework Convention on Climate Change (UNFCCC), which includes the US, must submit an annual Greenhouse Gas Inventory. For the recently updated Intergovernmental Panel on Climate Change (IPCC) methodology for GHG inventories, see “IPCC Updates Methodology for Greenhouse Gas Inventories,” May 13, 2019.

BBC Future and BBC World News, “Where Does Your Food Really Come From?,” a Follow the Food series that premiered on May 19, 2019.
Fashiondex Sustainable Fashion Forum, Los Angeles, October 4, 2018.
The Business of Fashion (BOF), “Stella McCartney in Conversation for the Launch of #BoFVOICES,” March 29, 2015.
The True Cost of Fast Fashion,” The Economist, November 29, 2018.
The True Cost,” 2016.
Ellen MacArthur, TED Talk, March 2015, “The surprising thing I learned sailing solo around the world.”
Kate Raworth, TED Talk, April 2018, “A healthy economy should be designed to thrive, not grow.”