This fascinating article on sustainable web design quantifies the costs of not greening your website.
The good news is that a leaner greener website is more efficient, which means your customers will be happier as well as the planet.
Green websites are faster
The longer a page takes to load into a browser, the more electricity it uses. Users get really frustrated by pages that take more than about two seconds to load - and those pages also use more electricity.
Web apps save emissions
However, the transfer of business processes to the internet is already reducing carbon emissions in other areas, such as reducing the need for business travel.
Even things like AirBnB, car-sharing websites, going paperless, automating manual processes, and preventing food waste by managing orders more effectively can reduce your carbon footprint.
Happy Customers, Happy Planet
Since a more efficient web site or application can make your customers happy as well as the planet, what's not to like?
Optimizing for lower emissions is tantamount to optimizing for general performance, so even non-green businesses have several compelling reasons to put their site on a diet: faster pages make for happier users, especially on mobile; they convert better and have better SEO, too. Adding climate benefit to that list makes an overwhelming case for cutting page size and data, especially for companies that are already sympathetic to a climate case (such as those that have signed the Climate Declaration). The internet as climate hero Despite its huge carbon footprint, the internet could also be a climate savior. The transition of old industries and services to the internet has the potential to save eight billion tons of CO2 by 2020, more than counterbalancing the projected 1.4 billion ton 2020 internet footprint.