Life-Cycle Analysis 

Some products and services are better for the environment and health than others, but for consumers, figuring out what choices to make can be complicated. Life-cycle analysis (LCA) is a tool that can help consumers, businesses, and organizations make informed decisions.

From Manufacturing to Recycling

What is life-cycle analysis, anyway? Here’s what it comes down to: evaluating the total environmental impacts of a product (such as a car) or a service or process (such as driving a car to work) over the life cycle of that product, service, or process. A thorough life-cycle analysis will focus on the entire life of a product or service, from resource extraction all the way to disposal, reuse, or recycling. This includes manufacture, processing, transport, distribution, use, maintenance, and reuse.

A life-cycle analysis can be narrowly focused or comprehensive. LCAs take multiple factors into account, such as energy use, durability, effects on climate change, and effects on air, soil, and water pollution. An LCA examines both positive and negative impacts of a product or service. Food waste is detrimental, but it can be used to create compost. Some greenhouse gases are emitted when food waste composts, but compost adds nutrients to the soil, increases water efficiency for farming and home gardening, and prevents additional carbon from entering the atmosphere.

There are different types of LCAs. Process life-cycle analysis includes accounting for energy and materials (including pollutants), as well as the conversion of those energy and material flows into categories of impact. These categories include global warming, air pollution, acidification and eutrophication, ecotoxicity, ozone depletion, and human health impacts such as cancer and asthma.

Input-output analysis looks at economic impacts and estimates financial flows. It examines the relationship between money and other factors, such as emissions. An input-output life-cycle analysis could examine the costs of the average US household’s food consumption in terms of energy costs, showing greenhouse gas emissions of red meat, vegetables, dairy, grains, fish, chicken, and beverages. Input-output LCA is easier and faster to do than process LCA, but it has its limitations: the commonly used data tables tend to be out of date; categories are lumped together; and the model is based on money, which doesn’t account for differences in product size and quality.

The illustration below shows one aspect of an LCA, how greenhouse gases are generated and absorbed by our use and disposal of products.

Greenhouse Gas Sources and Sinks Associated with the Material Life Cycle

(From the EPA report Solid Waste Management and Greenhouse Gases)

History and Development
LCA began in the US in the 1960s. In the early years, LCAs were often used to promote a specific product or perspective, such as cloth or disposable diapers. But as concerns about resource consumption have sharpened our understanding of the health and environmental impacts of the materials we use, life-cycle analysis has become more sophisticated, and international standards have developed. Advances in computer technology have also helped enhance LCA. Now there are many computer programs that help businesses analyze the impacts of the materials that go into their products. In the early days of LCAs, they were used mainly to inform—or persuade—consumers. Nowadays, LCAs can also help inform organizations, businesses, and governments as they strive to make environmentally responsible and healthful choices for their communities.

LCAs can be used and interpreted in different ways and for different aims. It’s important to identify who did the work, as well as any overt or hidden motives they might have. For example, a manufacturer of a compostable plastic material conducted an LCA that extolled the virtues of their product, while another LCA said just the opposite. Corporations and advertisers can take information out of context, manipulate data, or provide only a partial picture of their product’s environmental impacts in an attempt to “green up” their product’s image—and increase sales. Large-scale life-cycle analysis (i.e., taking climate change into account) is more useful than narrow-scale LCA (such as the effect on human health). Data can be hard to come by, and the consumer has to keep her eyes open to the information’s source and funding.

Further Reading

The U.S. Environmental Protection Agency’s information on life-cycle analysis

The U.S. Life Cycle Inventory Database

American Center for Life Cycle Assessment

The EPA’s fun, accessible poster about the life cycle of a CD or DVD

Green Building Solutions

Life Cycle Analysis: Understanding Environmental Impacts by David Allaway of the Oregon DEQ