MDN has an introduction to Web Sustainability (Remember SustyWeb from a couple of weeks ago?)
It provides a nice lay-person introduction to sustainable web description and practices. It also includes some links to useful resources such as https://www.webpagetest.org/carbon-control/ and https://www.websitecarbon.com/ for getting a sense of a websites's carbon footprint. I encourage you to try a couple of your favourite websites as well as your own you have developed to see how each compares relatively.
(via Introduction to web sustainability | MDN Blog)













