This is good stuff, thanks for bringing it to everybody's attention.
Lots of back-end-heavy websites are out there, burning power in datacenter servers and databases as well as routers, fiber-optic drivers, and end-user computers. I personally have been working on making WordPress's database operations faster and more efficient. There's lots of CO2 leverage there because there are many of those sites. (Yeah, we could outlaw WordPress because it's a power hog, but, that won't work.)
It's time for everybody to start thinking about web power footprint!