Climate change is an impact category in Life Cycle Impact Assessment that represents the potential contribution of greenhouse gas emissions to alterations in the Earth's climate system. Within the LCA framework defined by ISO 14040 and ISO 14044, climate change is one of the most widely assessed environmental impact categories, reflecting growing concern about human influences on global climate patterns.
In LCIA methodology, climate change impacts are typically quantified by converting various greenhouse gas emissions into carbon dioxide equivalents (CO₂-eq) using characterisation factors that reflect their relative global warming potential over a specified time horizon. The most commonly used time horizons are 20, 100, or 500 years, with the 100-year horizon being the default in most impact assessment methods. These characterisation factors account for both the radiative forcing efficiency of each greenhouse gas and its atmospheric lifetime.
The climate change impact category covers emissions of various greenhouse gases, including carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and fluorinated gases such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF₆). Each gas contributes differently to radiative forcing and persists in the atmosphere for different durations, as reflected in their respective characterisation factors.
Climate change is a midpoint impact category indicator that can be further linked to endpoint indicators reflecting damage to human health, ecosystem quality, and resource availability. At the endpoint level, climate change contributes to impacts such as heat-related mortality, changes in disease vector distributions, loss of biodiversity, sea level rise, and changes in agricultural productivity. These connections are established through characterisation models that describe the cause-effect chain from emissions to ultimate damages.
Glossary terms are clearer once you have seen them applied. Our guide to what LCA is and how it works walks through the complete methodology: goal and scope, inventory modelling, impact assessment, and interpretation.
If you are working on an LCA study and want it done properly, see how we approach life cycle assessment.
