Scientists have begun calculating how much electricity is consumed by the internet. It requires a great deal of electricity to keep all the servers and routers in climate controlled environments. Most electricity is still generated by the burning of coal. Generating that electricity creates CO2. Already the internet emits more CO2 than aviation. Worldwide only a small fraction of electricity is produced with clean renewable methods.
What does this mean about your website? If your website isn’t properly optimized then it requires more bandwidth and that creates more CO2. You might compare that to a single individual driving a giant Suburban that gets 13 mpg versus a smaller vehicle that might get 50 mpg.
I found this site that will calculate your site’s “emissions.”
Here is Thrive’s score:
I optimized the image down to 16% of its original size.
So optimizing your website will make your customers happy to use your fast site and it’s good for the environment!