Re: what will all these computers be computing
Very likely to be close to the truth, as it's certainly not domestic computing - more efficient machinery means my home power consumption has dropped significantly over the last few years, in spite of having far too much electronic tat switched on.
Obviously 'advertising' includes big search engines, timewasting 'friend' sites, large webmail providers, social media bainfart sharing systems etc...
Presumably the other significant part of the power usage is from the various simulation-related machines, primarily space and weather, i.e. stuff with an actual purpose?