12 June 2024
The need for rapid implementation of environmental investments to avoid the risk of emissions build-up
In decision-making frameworks for public policies and investments in all sectors, it is common practice to set emission reduction targets with time horizons of 5 to 25 years.
In these practices, it is crucial to consider the dynamic issues between the investment decision and the actual implementation of emission reduction measures. The longer it takes to implement a measure, the more the initial situation continues to emit, leading to a significant accumulation of emissions.
As shown in the graph below, while two scenarios starting from the same emissions level in 2024 reach the same emissions reduction target in 2050, the dynamics between the two scenarios are different.
Emissions reduction actions in scenario 1 were implemented early, as soon as the decision was taken, and gradually, while those in scenario 2 were implemented later and in a more concentrated way.
The result is the grey area representing the accumulation of emissions from scenario 2 compared with scenario 1, a consequence of the late implementation of the decision. This grey zone often tends not to be considered in conventional environmental assessments such as Life Cycle Assessment (LCA).
To take account of this grey area, dynamic LCA makes it possible to compare the two scenarios by looking at the differences year by year, rather than just in 2050.
This observation about the need for rapid implementation of environmental investments to avoid the risk of emissions build-up is all the more true if we integrate the associated social and economic effects with the environmental ones. From a societal point of view, it is preferable to adopt environmental measures gradually (scenario 1) rather than in a condensed manner (scenario 2), to give society time to adapt to the measures.
Written by: Frédéric Michel et Josquin Vandeputte.