In this article, we explain life cycle assessment (LCA) and carbon footprint assessment — two key tools used to evaluate and understand the environmental impacts of a product, service, or activity.
What is life cycle assessment?
Life cycle assessment (LCA) is a method used to measure the environmental impacts of a product or service throughout its entire life cycle. It is a rigorous, quantitative tool based on international standards (ISO 14040 and ISO 14044).
The life cycle of a product includes all stages, from the extraction of raw materials to its final disposal. In general, these stages are:
- production and distribution
- use
- end of life
LCA is a decision-making tool that helps identify exactly where environmental impacts occur. By analysing the full life cycle, it highlights the stages with the greatest impact and shows where action should be prioritised to reduce the overall environmental footprint.
Because it follows a standardised methodology, LCA also allows for objective comparison between different solutions.
What about carbon footprint assessment?
A carbon footprint assessment measures all greenhouse gas emissions linked to an activity, company, or product.
In practice, it helps identify where emissions come from, such as:
- energy use
- purchased materials
- transport and travel
- waste
- everyday services
By showing which areas generate the most emissions, it helps prioritise actions to reduce impact. These actions may include:
- reducing energy consumption
- choosing alternative materials
- optimising transport
- improving recycling
A carbon footprint assessment is therefore a simple but essential way to understand emissions, make informed decisions, and take effective action to reduce them.
Unlike LCA, which looks at multiple environmental impacts across the full life cycle (such as water use, resource use, pollution, and biodiversity), carbon footprint assessment focuses only on greenhouse gas emissions.
The two approaches are complementary:
- LCA provides a broad, multi-impact perspective
- carbon footprinting offers a focused, climate-specific view
How can they be measured?
Carrying out an LCA or a carbon footprint assessment requires a structured and rigorous approach. It is not just a matter of simple calculations — it involves using reliable data, defining clear assumptions, and interpreting results carefully.
These analyses are usually conducted by trained professionals.
In practice, both methods follow the same key steps:
- Define the scope: determine the product, service, or activity to analyse
- Collect data: gather information on materials, energy use, transport, waste, etc.
- Apply conversion factors: use environmental databases (such as ADEME’s Base Empreinte®) to convert data into emissions or other impacts
- Interpret results: analyse the findings, taking into account assumptions and uncertainties
Simplified approaches and tools
When these assessments are carried out in a simplified way, the goal is not to achieve perfect accuracy, but to identify the main sources of impact — for example:
- manufacturing
- energy consumption
- transport methods
- specific raw materials
To support this, several tools and databases are available. They provide reliable data and standardised methods, making it easier to perform assessments without calculating everything manually.
- ADEME / Base Empreinte® is a French database providing emission factors for carbon and environmental impact calculations.
- ADEME / Bilan Produit® is a tool for quickly estimating the environmental impact of a product or product group using simplified models.
- Ecobalyse is a free online tool for estimating environmental impacts, particularly for textiles and agri-food products.
- OpenLCA is a free, open-source software for carrying out detailed life cycle assessments and calculating multiple types of environmental impacts.
- SimaPro is a professional LCA software tool used for detailed and standardised studies, with extensive databases and indicators.
