Danny van Kooten is a Dutch developer who decided to reduce his carbon footprint and only needed a few keys.

Van Kooten is the author of a popular plugin for WordPress that helps website owners use the Mailchimp mailing list service. His plugin also makes the site bigger by adding several more lines of code. Every time someone visits your page, a server has to send part of van Kooten's code to their browser. Sending data to a browser uses energy. The less code you send, the less energy you use.

So van Kooten decided to lose weight. He "reformed" his plugin, making it more efficient, so now it sends 20 KB less data. Overall, the site will consume a little less energy each day.

Of course, 20 KB is a small reduction. But since 2 million sites use its plugin, it adds up. By his rough estimate, cutting the code reduced global monthly CO2 production by 59,000 kilograms, roughly equivalent to flying from New York to Amsterdam and back 85 times.

Not bad for two hours of hacking. "The code thing was by far the biggest thing I could do," he marvels, "and it's crazy, because it takes a lot less effort than not eating any meat."

Van Kooten's aha moment is one that is shared by web designers all over the planet. They call it "sustainable" web design and promoted by technologists who measure the energy budget of almost every scan and click in our information ecosystem.

If every adult in the UK sent one less 'thank you' email a day, it would cut 16 tonnes of carbon every year.

It's good to shine the spotlight on the CO2 footprint of our everyday software ...... and we here at exentric web design do what we can to help.