Systems solutions for sustainability transitions

The Transitions to New Technologies (TNT) Program focuses on the systemic aspects of technological change and draws on empirical case studies, novel modeling approaches, as well as scenario studies and robustness analysis to inform technology policy choices from a systemic perspective.

In 2017, researchers from the program, in collaboration with colleagues from the Air Quality and Greenhouse Gases (AIR), Energy (ENE), and Ecosystems Services and Management (ESM) programs at IIASA, developed a Low Energy Demand (LED) scenario. The research is part of the Alternative Pathways toward Sustainable development and climate stabilization (ALPS) collaborative research project with the Research Institute for Innovative Technologies for the Earth (RITE) in Japan. This scenario is an innovative illustration of alternative pathways for sustainability transitions through an end-use driven approach of technological and behavioral change. A derived scenario variant will also provide the integrative pathway that will be used in the global research initiative–The World in 2050 (TWI2050)–that supports the successful implementation of the Sustainable Development Goals (SDGs).

The LED project was initiated and completed as a fast track research input to the ongoing Intergovernmental Panel on Climate Change (IPCC) Special Report on 1.5°C. This project illustrates the comparative advantages offered by small, flexible research programs such as TNT that can act nimbly in response to important research opportunities. The study was also conducted as part of the longer-term ALPS collaboration framework with colleagues from RITE and involved a network of some 20 scientists from the AIR, ENE, ESM, and TNT programs at IIASA, as well as representatives from TNT’s network of alumni and research collaborators.

End-use and demand-driven “peak energy” in a scenario of meeting a climate target of 1.5°C without negative emissions technologies. Final energy output (EJ, top panels) and primary energy extracted (EJ bottom panels) for the Global North, South and the World respectively. Declining energy needs result from rapid end-use innovations including new technologies, business models, and behaviors that yield step changes in efficiency and reductions in resource requirements, while providing for higher amenities and services in a rapidly developing world.

The objective of the study was to develop an illustration of an alternative strategy for meeting the stringent 1.5°C climate target formulated as an aspirational goal at the Paris climate negotiations. Instead of relying on large-scale supply side technological solutions, most notably a massive deployment of so-called negative emissions technologies (removal of CO2 from the atmosphere), the new alternative pathway focuses on end-use, changing forms of service provision like the sharing and circular economy, as well as granular technology options. This could provide a step-change in resource efficiency, leading to a demand-driven “peak energy” that would allow meeting the 1.5°C target without any need for negative emissions technologies and with significant co-benefits for the SDGs.

A specific characteristic of this alternative scenario is that it combines a rich scenario narrative based on the insights gained from TNT’s research into historical technology transitions, and potential accelerators for systems changes with detailed modeling studies using IIASA integrated assessment models–GAINS, GLOBIOM, and MESSAGE–to examine the multiple implications of this alternative, rapid transition scenario. A paper is currently in the process of being published in a high-level journal, and the results have already been influential across almost all chapters of the forthcoming IPCC Special Report. A follow-up study extending this new scenario framework for an integrated approach to address SDG12 (responsible consumption and production) is currently being prepared for the TWI2050 initiative.


[1] Creutzig F, Roy J, Lamb JWF, Azevedo IML, Bruine de Bruin W, Dalkmann H, Edelenbosch O, Geels FW, et al (2018). Towards demand-side solutions for mitigating climate change. Nature Climate Change 8 (4): 268-271.

[2] Levesque A, Pietzcker RC, Baumstark L, De Stercke S, Grubler A & Luderer G (2018). How much energy will buildings consume in 2100? A global perspective within a scenario framework. Energy Policy (In Press).

IIASA Contributors


  • Charlie Wilson, Tyndall Centre for Climate Change Research, University of East Anglia, UK and IIASA
  • Nuno Bento, Instituto Universitário de Lisboa, Portugal and IIASA
  • Simon De Stercke, Imperial College-London, UK and IIASA
  • Jonathan Cullen, University of Cambridge, USA

Other highlights

Top image copyright: vectorfusionart | Shutterstock