Since human activities are closely linked to energy use, the energy system is a good candidate for providing a small, manageable list of interlinked lead indicators, with the ability to track sustainability.
Most important sustainability issues relate to the production and use of energy.
We will show that using the energy system as a framework offers the advantages of consistency and coherence.
Most importantly, it is possible to calculate future energy flows, demand and distribution with common energy-economic
models.
From these calculated future properties of the energy system, consistent estimates of the linked energy-based lead indicators can be derived.
Thereby, the energy models are not more reliable in predicting a single future indicator than economic or environmental models, but unlike these other models they have a strong link to most of the important sustainability issues in all three sustainability spheres.
Thus, for assessing the sustainability of the scenarios, the entire energy system is extrapolated, relationships between the sustainability dimensions are considered, and consistent estimates are generated.
This contrasts with other approaches, where single indicators are not physically interconnected and must be extrapolated independently, making consistency questionable.