How eco-friendly is Mobile Internet?

Nokia says that updating your Facebook status from a mobile phone consumes about 100 times less energy than if you were to do the same activity from a desktop PC.

Also, if only 100 million people were to use mobile phones instead of desktop computers to browse the Internet one hour a day, the amount of energy saved would be roughly equivalent to the annual greenhouse gas emissions of 430,000 cars.

There are about 1.4 billion Internet users worldwide and around 46% of them use Internet from both PC and their mobile phones according to this chart from DataViz.