Technology discontinuation as a continuous process: diesel, sustainability, and the politics of delay

The discontinuation of technologies - such as combustion engines, coal and nuclear power generation, or certain types of plastics - has become central to debates on sustainability, public health, and safety. Much of the existing literature and policy discourse, however, treats discontinuation as a discrete, well-defined phase at the end of a technology's lifecycle and as the implicit flipside of technology introduction. In this article, we propose conceptualizing discontinuation as a continuous process that unfolds throughout the entirety of a technology's lifespan, playing a critical role in its long-term survival. Drawing on a longitudinal, in-depth case study of diesel cars in Europe, we analyze how significant discontinuation pressures have existed for decades, repeatedly challenging, destabilizing, reconfiguring, and ultimately re-stabilizing diesel as a socio-technical system. We present a framework that captures how discontinuation efforts emerge, gain credibility, evolve, or are dismissed in relation to broader, stable imaginaries of socially desirable futures. In the case of diesel, we find that discontinuation efforts and counter-efforts specifically engaged two competing imaginaries of sustainability - one focused on local air quality and the other on global climate change - which allowed actors to strategically frame and rationalize the technology in ways that served their interests. By viewing discontinuation controversies as an inherent and continuous feature of a technology's durability, new policy options come to the fore. These include the need to shift the focus from the technology in question to what persists underneath, challenging the stability of underlying sustainability framings rather than merely reacting to moments of crisis. It also entails scrutinizing the politics of delay and the “technological neutrality”, which tend to favor continuation, and treating discontinuation policy more seriously as a form of innovation policy supported by long-term strategies, toolkits, and equivalent levels of funding.