Energy consumption increased and flattened
Between 1995 and 2010 the energy consumption of the entire Information and Communication (ICT) sector is roughly estimated to have increased three times. However, it has been shown that, over the period 2010 to 2015, the energy consumption of ICT has remained at about the same level, despite a continuing growth in subscriptions and an exponential increase in data traffic.
This ICT sector footprint includes life cycle emissions from all user devices, access networks, data centers and operating activities of the sector. Later development is under investigation; so far, no major trend shift has been identified. In total, between 1995 and 2015 the number of users increased approximately tenfold, and data traffic increased by a factor of one million.
For ICT the life cycle carbon footprint is strongly correlated with electricity consumption and the supply of energy. According to our latest research the ICT sector accounts for about 1.4% of overall global greenhouse gas (GHG) emissions.
Projections of ICT’s future emissions vary
The connection between data traffic and energy consumption has been debated over the years. Several projections have been published. In retrospect, many projections, including our own, have turned out to overestimate the future energy consumption and carbon footprint of ICT.
Based on measured data and detailed sector knowledge, our detailed 2018 study estimates the ICT sector carbon footprint to be about 730 Mt CO2-equivalents (CO2-eq) for 2015. This is well below previous projections, indicating that the sector is hard to model without the use of detailed measured data. Forecasts need to be based on detailed assessments of the different contributions and understanding of the sector’s development rather than on intensity metrics, which have been shown to change rapidly.
Footprint scales with subscriptions not data
Over the years, global data traffic has increased exponentially. Several earlier projections have assumed the carbon footprint of the ICT sector to increase in line with the exponential increase in data traffic. Looking at the historical footprints, this has been shown not to be the case. Instead, the ICT carbon footprint has been shown to depend to a much greater extent on the number of subscriptions.
Up to 2010 the number of subscriptions grew rapidly, but in recent years growth has started to decline, though still continuing. The carbon footprint per user has been flattening out since 2010, due to a decrease for an average fixed user and a slight increase for an average mobile user. The trends towards larger smartphones and increasing smartphone use for media and entertainment activities are important drivers behind this development.
For 2015, the carbon footprint for an average ICT subscription was about 81 kg CO2-eq. This should be compared to the global average total emissions of about 7000 kg CO2-eq per person.
The impact for each gigabyte of data is steadily decreasing. For 2015, it was calculated to be about 0.8 kg CO2-eq per GB data, a decrease from 3 kg CO2-eq/GB in 2010. This trend is believed to continue due to more efficient networks outweighing the ever-growing increase in data traffic, driven mainly by increased consumption of videos.
ICT mature countries may indicate future
Studies on Sweden, rated among the most ICT-mature countries in the world, show a decreasing carbon footprint and energy consumption for the ICT sector.
Similar decreasing energy trends have been reported for Germany and the US. Thus, current data seems to indicate that footprints of ICT will not continue to grow once a certain level of ICT maturity has been reached.
Continued industry-focus on energy efficiency in all stages coupled with use of renewables helps maintain the decreasing trend of the ICT footprint. This is despite growth in subscriptions, as more people get connected and the Internet of Things (IoT) expands.