“I’m horrified,” says Valentina Karellas. “I know grams because I work with them every day and I know how much 10g weighs. And that’s just one page.” She’s just learned that every visit to her website’s homepage generates 9.89g of carbon emissions. That’s almost 10 times the 1g target recommended by the Eco-Friendly Web Alliance, which offers accreditation for eco-friendly websites. The revelation is at odds with the rest of her business, which is set up to be sustainable. Karellas designs and makes knitwear in her London workshop, which she describes as wearable art. (Sean McManus)