Recent research examines hypotheses about the role of final energy demand levels that underpin models used in a prominent international report on climate change. The researchers argue that these models under-represent the potential for global energy demand reduction to contribute to carbon mitigation targets, particularly in reducing dependence on carbon dioxide removal techniques.
The Intergovernmental Panel on Climate Change (IPCC) Special Report on Global Warming of 1.5°C (2018)2 assesses different emissions pathways for limiting global warming to 1.5°C or 2°C. The report analysed 411 emissions scenarios, drawn from 31 integrated assessment models (IAMs). These IAMs provide a representation of complex interactions between the global economy, the energy system, greenhouse gas emissions and the climate system, and, as such, are built on various assumptions about how these factors affect each other. One of the factors included in many IAMs is final energy demand – the total amount of energy consumed globally each year.
The researchers suggest that various inputs into the IAMs can act as drivers of final energy demand and may influence decarbonisation outcomes and emissions pathways. This study considers how final energy demand is incorporated into the IAMs used for 1.5°C and 2°C scenarios in the IPCC report, and how this factor could affect the perception of energy demand reduction drivers in climate change policy development.
The researchers identified the scenarios in the report that both limited global warming to 1.5°C or 2°C and included reporting of future energy demand projections to 2100 (217 cases in total) using the online Integrated Assessment Modelling Consortium’s Scenario Explorer tool. They conducted a series of analyses on these scenarios aimed at addressing five key topics:
- How is final energy demand predicted to change through the scenarios?
- How is final energy demand related to economic growth across the scenarios?
- How do the mitigation pathways for high-energy demand and low-energy demand differ?
- How do different levels of final energy demand affect outcomes for decarbonisation and use of carbon dioxide removal techniques?
- How do changes in final energy demand affect the ability to achieve emissions targets?
The researchers report that only 5% of IPCC scenarios involved substantial energy demand reduction from current levels by 2100. The majority of scenarios projected demand reductions only in the short term or not at all, they say, with increases in demand after 2040 of 1–2% per year and final energy demand by 2100 well above 2020 levels. Most IPCC scenarios had GDP growing at around 2% per year and energy demand at around 0.5% per year, but the researchers argue that historically these two measures have been tightly coupled, suggesting that this difference in growth rates may be unrealistic to achieve or sustain at least in the short to medium term.
Scenarios involving relatively high levels of final energy demand compensated for this to some degree with higher levels of electrification and renewable energy sources, according to researchers. However, they highlight that lower levels of demand did not lead to reduced reliance on carbon dioxide removal techniques. While higher energy demand in 1.5° C scenarios tends to lead to overshoot (temporarily exceeding target levels), according to the researchers, demand reduction is rarely used as a mechanism to lower cumulative carbon emissions compared to alternative scenarios.
The researchers argue that the IAMs used in the IPCC’s 2018 1.5°C report have a techno-economic focus (i.e. focusing on technical and financial parameters) and do not fully explore the potential for further energy demand reduction in achieving lower carbon budgets (with only two scenarios that explicitly consider final energy demand reduction). They claim that, in these models, lower demand largely functions to reduce investment in renewable energy sources, and, therefore, its potential to minimise dependence on unproven carbon dioxide removal techniques is not fully explored.
They also draw attention to the report’s decoupling of economic growth and energy demand, despite established relationships between these factors, highlighting that energy demand reduction mostly features in IAMs in the short term, when such decoupling is likely to be challenging, and rarely in the medium- to long-term when it may be more feasible. They argue that the design of IAMs should be reassessed to better incorporate energy demand factors and utilise potential emissions savings. They suggest that future research should consider how different demand levels could meet basic human needs while limiting global warming. The researchers propose that an interesting analysis would be to determine whether a new set of over 1 200 IAMs pathways published in the IPCC’s Working Group III contribution to the Sixth Assessment Report3 has started to address these issues.
The use of final energy demand reduction in decarbonisation pathways is limited by several factors – such as complexities in modeling end-user behaviour and difficulties in predicting effects of novelty and innovation1 – as well as an imperative to maintain GDP growth, which is typically closely coupled with energy demand.
- Wilson, C., Pettifor, H., Cassar, E., Kerr, L. and Wilson, M. (2019) The potential contribution of disruptive low-carbon innovations to 1.5 °C climate mitigation. Energy Efficiency 12: 423–440.
- IPCC (2018) Summary for Policymakers. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty[Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. World Meteorological Organization: Geneva, Switzerland.
- Riahi, K., R. Schaeffer, J. Arango, K. Calvin, C. Guivarch, T. Hasegawa, K. Jiang, E. Kriegler, R. Matthews, G.P. Peters, A. Rao, S. Robertson, A.M. Sebbit, J. Steinberger, M. Tavoni and D.P. van Vuuren (2022) Mitigation pathways compatible with long-term goals. In: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [P.R. Shukla, J. Skea, R. Slade, A. Al Khourdajie, R. van Diemen, D. McCollum, M. Pathak, S. Some, P. Vyas, R. Fradera, M. Belkacemi, A. Hasija, G. Lisboa, S. Luz and J. Malley (eds.)]. Cambridge University Press: Cambridge, UK and New York, USA.
Scott, K., Smith, C. J., Lowe, J. A., Carreras and L. G. (2022) Demand vs supply-side approaches to mitigation: What final energy demand assumptions are made to meet 1.5 and 2 °C targets? Global Environmental Change 72: 102448.
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“Science for Environment Policy”: European Commission DG Environment News Alert Service, edited by the Science Communication Unit, The University of the West of England, Bristol.
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The contents and views included in Science for Environment Policy are based on independent, peer reviewed research and do not necessarily reflect the position of the European Commission. Please note that this article is a summary of only one study. Other studies may come to other conclusions.
- Publication date
- 28 September 2022
- Directorate-General for Environment