Conclusions: Exploring synergies between efficiency and effectiveness

There is an urgent need for effective measures to stop the explosive growth of global energy consumption and related environmental impact. Information and Communication Technologies (ICT) play since many decades a central role in increasing efficiency and improving effectiveness of energy usage in many vital sectors of the economy. This has however led to an explosive growth of the energy used by the ICT sector itself and the call for decreasing the carbon emissions of ICT. On the other hand, improving efficiency of energy use has also led to an absolute increase of consumption and of carbon emissions (Jevons paradox). In this book, we present a holistic approach for Green IT: working on two parallel action lines to green the IT sector itself (Greening IT) and deploying ICT to green the other sectors (Greening by IT).