It is totally nonsense and doesn't help at all.
Forgiving my own displeasure at google-everything, I think I can at least appreciate that they might not be all evil all the time – perhaps they could even influence people in a positive way?
Also excuse the related tangent and cherry picking, I am not condoning most of China's behaviour, but being big and bad doesn't necessarily mean that they cannot produce positive effects. [0]
To give an extreme example, how would you react if Exxon Mobil were to claim to be carbon-neutral because they offset the footprint of all their datacenters, offices, drilling facilities, and supply chain? I am sure you would call bullshit, as their whole business is about extracting carbon from the earth to put it back in the atmosphere.
I just think it is unfair to claim that you have zero impact on this planet until you really offset it for real.
Google should include the cost of user computers running JavaScript.
Even a laptop in sleep mode uses ~2W, and a desktop - 6-10W. Average wifi router uses constant 6W if I'm not mistaken.
6-10W kinda sucks for an active desktop, much less a sleeping one. My development system while in S0 currently measures 3.04W (of course, ~30W when running hard).