According to the revised Lean ICT Report the Digital energy consumption has increased by 6.5% yearly since 2015. "Digital" includes Internet, all our digital devices and the infrastructures needed to support them.

Converted in GHG emissions, given the worldwide electricity mix, this represents around 3.5% of global GHG Emissions. It is already at the level of the airline industry. And the trend is worrying with a projection to double by 2025.  

"Digital footprint" comprises several energy consuming focuses: Production of devices, Usage of devices (Electricity consumption for batteries and data consumption relying on electricity consumption too), Destruction of obsolete devices

All of them are at the core of green ICT (Information and Communication Technologies) thoughts to decrease our carbon footprint.

Existing software engineering models do not pay much attention to green computing that focuses on the effective use of natural resources. However, making information systems greener is possible through different steps of projects: design, development per se, installation phase...

On top of that, more and more models are being discussed and tested: green holistic methodologies, emergence of EI (environmental informatics) or Science Based Targets (SBT) methodology.