Erol GelenbeGelenbe, ErolT.V. Gopal , L. Lau , L. Chang , G. Adamson2025-10-062022978166548410710.1109/ISTAS55053.2022.102271072-s2.0-85172357750https://www.scopus.com/inward/record.uri?eid=2-s2.0-85172357750&doi=10.1109%2FISTAS55053.2022.10227107&partnerID=40&md5=33e307886947d4c671d69edb3207b489https://gcris.yasar.edu.tr/handle/123456789/8760https://doi.org/10.1109/ISTAS55053.2022.10227107The paper considers important issues surrounding the energy consumption by Information and Communication Technologies (ICT) which has been steadily growing and is now attaining approximately 10% of the worldwide electricity consumption with a significant impact on greenhouse gas emissions. The perimeter of ICT systems is discussed and the role of the sub-systems that compose ICT is considered. Data from recent years is used to consider how each of these subsystems contribute to ICT's energy consumption. The positive correlation between the penetration of ICT in some of the world's different economies and the same economies' contributions to undesirable greenhouse gas emissions is also discussed. We also examine how emerging technologies such as 5G edge computing and cryptocurrencies are contributing to the worldwide increase in electricity consumption by ICT despite the ever increase in efficiency in energy per bit processed stored or transmitted by ICT systems. The measurement of specific ICT systems' electricity consumption is considered and the manner in which this consumption can be minimized in two specific technical contexts is also discussed in some detail. © 2023 Elsevier B.V. All rights reserved.Englishinfo:eu-repo/semantics/closedAccessData Centers, Edge Computing, Energy Consumption, Information Technology, Radio Access Networks, 5g Mobile Communication Systems, Electric Power Utilization, Gas Emissions, Green Computing, Greenhouse Gases, Radio Access Networks, Datacenter, Edge Computing, Electricity-consumption, Energy-consumption, Greenhouse Gas Emissions, Information And Communication Technologies, Optimisations, Sub-systems, Technology System5G mobile communication systems, Electric power utilization, Gas emissions, Green computing, Greenhouse gases, Radio access networks, Datacenter, Edge computing, Electricity-consumption, Energy-consumption, Greenhouse gas emissions, Information and Communication Technologies, Optimisations, Sub-systems, Technology systemInformation TechnologyEnergy ConsumptionData CentersEdge ComputingRadio Access NetworksConference Object