Arnulf Gruebler on System Boundaries

During the first week of the AEMS 2022, we visited the beautiful International Institute for Applied System Analysis (IIASA) in Laxenburg. After a short tour through the Institute, which was formerly a residence of the Austrian royal family, Brian Fath and Arnulf Gruebler gave their lectures. Arnulf Gruebler talked about basic concepts of system analysis, our energy system and its (in)efficiencies, and different perspectives on meeting the 1.5°C target.

Arnulf Gruebler is a Senior Research Scholar and Acting Program Director of the Transitions to New Technologies Program at IIASA, as well as a Professor at the School of Forestry and Environmental Studies at Yale University. His research is highly interdisciplinary and combines systems thinking and mathematical modelling of complex systems with both long-run historical analysis and future scenario techniques.

Arnulf first starts by explaining the basic concepts about the system system boundary. The interactions of the elements are essential and form the whole system. He has conveyed an important message on this —- the structure and function arise from the interactions rather than from the characteristics of its elements. System boundaries are a delineation of which elements are included in a system analysis and which are not. Arnulf showed us an approach to energy system representation, which is used to describe the pathway of energy throughout the system. He first pointed out that it is necessary to pay attention to the input and output of the system. It is typical that many countries import energy into the system and use the energy to produce products and services, with waste heat and greenhouse gas emissions as output, which drives us away from a sustainable path. He also pointed out that the end-users of energy are actually not part of these system representations, thus outside the system boundary. The representations usually just end in a final consumption aggregate, not clarifying what that actually means. But that is a crucial mistake, since the biggest energy losses happen at the end-use-stage. This was one of Arnulf Gruebler´s central points: user behaviour is more powerful than technological efficiency!

He clarified that with the following example: A school bus with 20 people, being technologically very inefficient, becomes more efficient than a much more efficient Toyota used by one person – the end-use matters, since here lie the most energy and efficiency losses.

With further graphs, Gruebler showed us the drastic differences between the supply and the end-use of energy, water and materials: Only 5% of the energy we extract is actually used in the end, after all the production steps and also taking these end-uses of consumers into account (which Arnulf Gruebler pledges for). Becoming more efficient and adapting our lifestyle is inevitable!

Afterwards, Arnulf Gruebler talked about the 1.5°C goal and pointed out two scenarios to reach these goals:

1. Conventional Scenario: Geoengineering and negative emissions help us to get to net zero in the long run, but inertia in policy, social & technological change leads to an overshoot in the short term. Overshoot as supply-side options scale slowly, but need long term development for high demand scenarios.
2. Low Energy Demand (LED) Scenario: There can be a more rapid transformation driven by end‐use changes (efficiency & behaviour). Granular, distributed supply side options lead the way for scaling other mitigation options and can achieve rapid change under low demand.

He pointed out that one should be very critical when looking at an analysis of a narrow system, as the social, environmental and economic systems are greatly intertwined. Sustainable development requires extended system boundaries, considering the social aspect (what is the societal use, for whom?) and the environmental aspect (provisioning/limiting resource use).

Open questions raised by the audience put this discussion even further. There were questions on the centralized and decentralized approaches on energy transition, as well as Geoengineering. Arnulf also emphasized it’s been too much talk over energy transition and now it is really high time to act now.

Overall, we need to change our behaviour as consumers, as that is the most essential way of increasing resource-efficiency. Also, we must move into the realm of sustainable development, providing for inclusive well-being, involving the people left behind from our system, making people aware of what we cause through consumption, increasing different forms of development capital and, of course, remaining within the planetary boundaries.

Based on the lecture "Planetary boundaries, energy, models" by Arnulf Gruebler during AEMS 2022.
Written by: Violet Fan and Lukas Kronsteiner