LOL best laugh of the day so far ... I thought perhaps the author might have been quite young, they are not, so I would guess it's a fun or not so serious way of saying something without mentioning the real culprits, most of us could probably instantly think of more significant energy wastage - an A.I. snoop though would be well fooled. The author is of an age that should well understand the waste of power in emails is the extra energy for resources required for non text emails - and the multitude that now get sent instead of a text based email. How many lives have I saved by refusing to enable html?
Of course more power (electricity) has been lost for the hours some are engaged in fruitless searches, visiting the websites that are actually near pointless, and loading the spam of the endless ads thrust onto most web users. There's a long list obviously, ymmv depending on view points.