Life-Cycle Assessments


Life-cycle impacts are the all-encompassing environmental impacts caused by a process, service, or product during their entire lifetime. When accurate, life-cycle impacts can effectively answer the question: “How will the environment change if I create this process, service, or product?”

Life-cycle assessments [LCAs] are scientific studies responsible for determining life-cycle impacts. LCAs analyze GHG emissions, toxic pollution, resource exploitation, energy consumption, and anything else that may alter the environment, directly or indirectly. The more factors an LCA assesses, the more likely it is that the resulting life-cycle impacts will be accurate.

LCAs that aim to be as accurate as possible can be quite complicated, but all follow roughly the same structure. And while individuals aren’t expected to perform a comprehensive LCA before every purchase, it’s important to know how they work. Understanding the basics of an LCA can help environmentally-conscious individuals make sensible decisions.

The general technique for conducting an LCA consists of asking 6 questions during every step of the LCA:

  • How much raw material is used? How much is available?
  • How much energy is needed? How is it sourced?
  • How much waste is created? How is it managed?

The remainder of this section will focus on LCAs that assess a product’s life-cycle impacts. LCAs for processes and services also exist, but they’re often harder to visualize.

Step 1: Before

Before a product is made, lots of resources have already been consumed. Not just time and money, but also physical resources needed to design, produce, or transport the product.

Design and Infrastructure

Designing a product is the first step of the manufacturing process. Its impacts are typically minimal, but some “test as we go” design techniques can challenge that assumption.

Then, setting up the infrastructure for manufacturing is essential. This can include securing a supply of raw materials, setting up factories to transform these raw materials, building roads to allow employees to commute to these factories, providing electricity for lighting along these roads, and so on. Very quickly, a product can cause numerous environmental impacts – even though the product in question hasn’t been created yet. Comprehensive LCAs make sure that these early impacts are included in the assessment.


Once a product’s manufacturing begins, impacts will vary significantly between different processes, services, or products. One thing that remains true for all products is that any material used comes from somewhere. It’s up to LCAs to find out whether that “somewhere” is a mining pit, a sustainably-managed forest, or an intensively-farmed cropland – and what consequences each of these scenarios would entail. For all material, LCAs will have to answer the 6 questions presented previously.

Virtual products can also cause plenty of environmental impacts, as we’ll see in an upcoming section.


From conception to disposal, products can circle the globe multiple times. During production, this is often due to raw materials that can only be supplied from distant regions of the world. Additionally, transportation impacts can result from the global economy’s mechanisms that make manufacturing cheaper if split between dozens of countries. LCAs are responsible for tracking these impacts.

Here‘s an example of a complex product that relies on globalization and transportation. While we can’t verify the statistics presented, this 5-minute detour shows how modern products require loads of different materials and suppliers – and transportation to tie the whole thing together.

Step 2: During

The “During” phase is often the easiest part of an LCA, since the impacts are relatively straight-forward. For example, it doesn’t take much research to understand that when a standard combustion vehicle is used, both GHGs and toxic pollutants are emitted. Nonetheless, LCAs apply the same level of scrutiny as was required in the previous step of the process, to ensure that all life-cycle impacts are captured.

In general, any product that lights, moves, heats, or cools is powered by some source of energy. While efforts can be made to reduce that energy’s impacts by switching to low-carbon sources, this often induces greater impacts upstream and downstream. This is the case for electric vehicles for example, although they still end up emitting less GHGs than combustion vehicles in moderately clean electricity grids.

Products also have transportation impacts in the “During” phase, particularly when personal vehicles are used to purchase products [e.g. purchasing food from local farms].

Step 3: After

An LCA also analyzes how products are handled at end-of-life. For recyclables and compostables, the recovery of valuable materials can bring positive impacts on the environment. The same can be said for products that allow reuse or recycling. For non-recoverable waste, an LCA will likely find negative impacts.

Transportation is required during disposal as well, either for waste collection, transport between waste facilities, or on-site operations [e.g. landfill compactors]. If waste is exported to a weaker waste management system halfway across the globe, additional impacts will ensue.


LCAs have the complex task of collecting and analyzing all the environmental impacts caused by a process, service, or product over their entire lifetime. Individuals and organizations have the much more difficult task of comparing all these environmental impacts and establishing priorities.

Governments and companies can use LCAs to effectively communicate life-cycle impacts to individuals. Governments can also use LCAs as scientific evidence to justify ambitious environmental policies. Lastly, LCAs can be used to highlight low-impact practices that could easily become widespread, with the right incentives.