Black software — the energy unsustainability of software systems in the 21st century

Abstract Climate change is happening, and the information and communication technology (ICT) industry is providing solutions to enable a more sustainable future. ICT enables enhanced manufacturing processes, optimized logistics, solutions supporting environmental protection and solutions facilitating climate change adaptation, for example. The performance of ICT hardware and electronics has increased tremendously. The capabilities of microchips have increased ~100,000-fold in the past 30 years and the power efficiency has increased a million-fold. Yet, various reports show that the ICT sector increases its carbon footprint and energy consumption, while other sectors are lowering their impact on our planet. Thus, there seems to be an adverse development ongoing where most industry sectors can lower their carbon footprint while the ICT sector increases its consumption. This paper looks at the development of the ICT sector and seeks to understand the current development. We argue that a major reason for the rebound effect we are seeing within the ICT sector is the lack of understanding in energy consumption and the cost pressures of developing digital services. The results are software and services that could be much greener and energy efficient but seem to rather go toward a darker direction. The ICT industry and software engineering needs to do a clear change of course and take accountability of their activities.