Life Cycle Assessment (LCA) is an environmental impact assessment tool that is generally static, linear and limited to the description of physical flows when the aim is to assess the impacts associated with a sector or a product.
The question of the relevance of the method for quantifying the environmental consequences of public policies over a given time horizon was raised when the French law concerning the energy transition for green growth (the “LTECV” law), which is liable to modify the country’s energy mix, was passed.
A method was therefore developed to anticipate the potential impacts of one of the objectives set: the introduction of 15% renewable energies into the transport sector by 2030.
This approach, known as consequential LCA, uses the MIRET French energy sector prospective modeling tool (IFPEN’s TIMESa model), coupled with an LCA approach(1).
The TIMES-MIRET economic optimization model reveals energy flowb modifications resulting from exogenous mobility demand trajectories driven by objectives such as those of the LTECV.
The differential between material and energy flows with and without the LTECV objective is then translated, via the EcoInvent LCA database, into a differential between extractions and/or resource waste and/or pollutant emissions into the environment. The impacts associated with these extractions and emissions are then assessed using the Impact World + method in terms of consequences on human health, climate change or ecosystem quality.
A spatial approach is currently taken into consideration to more effectively model the environmental impacts on a local scale (e.g. impacts on water, soil, etc.). This issue is continuing via a PhD thesis jointly supervised with INRA and CIRAIG(2). The research aims primarily to determine how the geographic variability of these impacts is influenced by that of data derived from TIMES-MIRET and LCA models. Geographic price disparities of biomass resources are particularly tested here.
a- See article on SCelecTRA project.
b- Examples: mobilization of resources, activities of refining and biofuels sectors, new electricity or gas requirements, along with the evolution in car stock and other means of transport.
(1) F. Menten, S. Tchung-Ming, D. Lorne , F. Bouvart. Lessons from the use of a long-term energy model for consequential life cycle assessment: The BTL case - Renewable and Sustainable Energy Reviews, 2015, 43, 942–960
>> DOI : 10.1016/j.rser.2014.11.072
(2) L. Patouillard. PhD thesis (2013-2017): Regionalization in consequential LCA: case of alternative sectors for transport in France in 2030.