Sustainability is the biggest challenge of the 21st century; without it, human civilization will be unable to continue. This chapter explores the relationship of computing technologies to sustainability.

The race for sustainability

by Koen De Bosschere

Climate change is now felt all over the planet, leading to changing natural ecosystems, and eventually to loss of biodiversity. Climate change is not only about melting ice caps, and rising sea levels, but also about fresh drinking-water supplies, food security, and water needed for manufacturing, agriculture, transportation and energy production. Climate change affects many aspects of our daily lives.

However, sustainability is wider than climate change. It is about organizing the world within the limits of planet Earth both today and for the generations to come. One aspect of it is the use of raw materials, which are finite on a finite planet. Modern information and communication technology (ICT) devices require more than 60 minerals from all over the world, some of which are hard to mine, are scarce, or are mined in socially unacceptable conditions. Once used in a device, they are difficult to recycle; but without efficient reuse and recycling, there cannot be true sustainability.

Modern ICT devices are very power efficient, leading to a situation where more energy is needed to produce them than they will use during their entire lifetime (“embodied” versus “operational” energy use). Hence, integrating multiple functions into one device is more sustainable than creating separate devices per function. Contrary to common belief, continuing to use an old device is often more sustainable than buying a new, more power-efficient one. This shows that a full lifecycle assessment can lead to counterintuitive conclusions, and that such an assessment is essential in order to come up with sustainability solutions with real impact.

Sustainability is perhaps the most important grand challenge of the 21st century and it affects everything we do. This chapter looks into ways to make computing sustainable and suggests how computing can contribute to sustainability goals.

This part contains three contributions.

• “What does it mean to be sustainable?” This article discusses the definition of sustainability in the context of ICT: energy, water and material consumption, and how to reduce and/or neutralize them. The main conclusion is that there is a need for universally agreed life cycle models for computing devices and services. Without such models, it is impossible to make effective sustainable design decisions, to make operational decisions when they are in use, and design new business models for the ICT industry.

• “Sustainable materials and production”. This article focusses on the environmental impact of the physical layer of computing systems. It analyzes the origin of the embodied emissions of modern technology nodes: the high number of required semiconductor grade minerals and the increasing number of energy, gas, and water consuming process steps to produce a chip. Finally, there is the technical challenge to effectively recycle semiconductor components.

• “Towards sustainable computer architecture: A holistic approach”. This article argues that sustainable development requires a holistic approach and involves multi-perspective thinking. Applied to computing, sustainable development means that we need to consider the entire lifecycle of a product. Analyzing current trends reveals that the embodied energy footprint is, or will soon be, more significant compared to the operational energy footprint. The article summarizes what computer architects and engineers can and should do to better understand the environmental impact of computing, and to design sustainable computer systems.

Key recommendations

• Design and improve validated lifecycle models. These models should not only encompass factors like embodied and operational energy but should also comprehensively account for the ecological impact of activities such as mining, water usage, the use of chemicals in production, and the environmental consequences at the end of a product’s life cycle.

• Develop sustainability-focused design methodologies. By making a low ecological footprint a core design objective, designers will naturally take into account factors like repairability, reusability potential, recyclability, and the effective management of end-of-life processing right from the initial stages of product development.

• Develop sustainable production techniques for semiconductor components. Such techniques should reduce the emission of greenhouse gasses, the use of toxic, hazardous and critical raw materials, the consumption of ultra-pure water, and the amount of energy needed to produce semiconductors.

• Create new business models incorporating the full lifecycle. HiPEAC underscores that the absence of viable sustainable business models is a significant barrier to meaningful actions by companies aimed at enhancing the sustainability of their products. Therefore, rethinking business models is crucial to drive positive change in the sustainability landscape.

• Prioritize ICT for green applications. In addition to developing more sustainable digital technologies, HiPEAC recommends that the community focuses on developing “ICT for green applications”, and works collectively with various domains in investigating how ICT technology could reduce the environmental impact of key processes in these domains.

AUTHOR

Koen De Bosschere is a professor in the electronics department of Ghent University, Ghent, Belgium.