So the digital world uses a lot of electricity.
Yes it does, but it has the potential to reduce energy consumption in other areas. For example, it could theoretically, reduce the number of business trips people make. I say "theoretically" because I don't see it happening much yet. There's also the possibility that it would cut down the amount of shopping trips people do. Imagine if, instead of everybody going to the supermarket, shopping was delivered. I imagine you would see a net drop in energy consumption if most people did it. One day in the not too distant future, all books will be delivered electronically. Imagine the savings not having to transport all those dead trees around.
As a side note, the incidence of teenage pregnancy has dropped off a cliff in the UK. The correlation between not having the internet at home and teenage pregnancy is something like 0.99, which is to say it is very strong. Also, teenagers are drinking less and taking fewer drugs, which, again, seems to be correlated with the increase in the digital world.