Watching videos online, or streaming music, and indeed data exchange of any kind consumes energy and so produces Greenhouse Gases (GHG).
The third source of CO2 emissions in developed countries is the purchase and usage of computers, tablets, smartphones and their internet usage. The importance of new technologies is increasing every year, and our CO2 emissions are doing the same. Have you considered keeping using your 'obsolete" and yet still functional gadgets instead of discarding them?
Over 3.3 billions of daily queries on Google's search engine generate 600 tons of CO2 per day, amounting to 241 000 tons yearly. However viewing videos online consumes yet more energy. Every day, a billion videos are viewed on Youtube. The environmental impact of VOD is mind boggling, it generates 10 million tons of CO2 per year, which is equivalent to the output of the city of Glasgow, Scotland.
Having a good online carbon footprint is all about adopting some simple habits. Youtube is mainly used for listening to music. However, because Youtube also streams video while you are listening, a lot more energy is consumed and a lot more carbon dioxyde produced. Using other music streaming services - those who don't stream video at the same time - will reduce your footprint. Using offline devices (CD, MP3) will reduce our online CO2 pollution even more. Video streaming make up 1% of the world's CO2 emissions. Netflix and Amazon Prime combined produce as much as the country of Chili.
In the end run, at least one fifth of our online carbon footprint comes from videos. The digital sector is, by itself, responsible for 4% of the world's CO2 emissions, which is about as much as air travel. But our online activity's energy needs continue to grow by about 9% per year. So let's learn to disconnect.. and maybe go for a walk in the woods?