DANNY VAN KOOTEN is a Dutch programmer who decided to reduce his carbon output by no longer eating beef or flying. Then, five months ago, he made a change that had an even bigger impact—and it took only a few keystrokes.
Van Kooten is the author of a popular WordPress plug-in that helps website owners use the mailing-list service Mailchimp. Install van Kooten’s plug-in and visitors can sign up for your Mailchimp list directly via a form embedded on your site. His plug-in also makes the site slightly larger by adding several thousand 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 slim things down. He “refactored” his plug-in, making it more efficient, so now it sends 20 KB less data. Overall, the site would use a little less energy every day.
Of course, 20 KB is a teensy reduction. But since 2 million websites use his plug-in, it adds up. By his crude estimate, trimming the code reduced the world’s monthly CO2 output by 59,000 kilograms, roughly the equivalent to flying from New York to Amsterdam and back 85 times.
Not bad for two hours of hacking. “The code thing has been 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.”