Within the last 10–15 years the internet has become an essential part of our everyday life. If you have five minutes time during the day, just sit back and think about a regular day for you. I am sure you will be amazed about the amount of actions – applying the internet – you take most likely even before leaving home in the morning. David Bauer described the formerly futuristic year 2000 in this way in his essay “2000, the Year Formerly Known as the Future”. Remarkable how one takes those wonders and innovations of the last few years as granted today.
Anyhow, I am sure most of us are not aware that the huge amount of internet usage by all of us creates a lot of pollution due to the energy consumption of growing data centers (do not forget the air conditioning for the computers) that are extended to meet the permanently increasing traffic demands. Also cell phone towers allowing us to access our cloud serviced data from nearly every spot in the civilized world demand energy to allow 24/7 usage. In the year 2005, European internet operators used 14 TWh to enable their machines to work. Five years later the energy consumption has risen to 21 TWh and is expected to be 36 TWh in 2020. 20% of this power consumption was due to A/C.
So, shall we stop using the internet to be able to save the planet? Hardly possible. But there are potential energy saving mechanisms. For example, temporarily allowing unused parts of network devices to go to a sleep mode (smart standby) with very little energy usage. Unfortunately, this way of energy saving does not allow instant availability of all services if the traffic rises.
Every method of energy saving has its setbacks, being the balance between the demands of the internet users and the limitations of energy usage. But without these green technologies we might not be able to meet the exponentially increasing energy consumption of the internet.
– Andreas Neidlinger
 https://medium.com/we-live-in-the-future/cbd6bdc6b283 (last access 18.08.2013)
 D. R. Recupero, Science 2013, 339, 1533-1534.