The coloured stripes that explain climate change

In 2017, Ellie Highwood, a professor of climate physics at the University of Reading, shared a photograph on Twitter of a 'global warming blanket' she had crocheted. The rows of colour on the blanket represented average global temperature changes over time. Little did she know that a graphic version of her blanket, created by a colleague, would become a global symbol of climate change. The 'climate stripes' image has been embraced by activists worldwide, used as a cover image for Greta Thunberg's The Climate Book, and featured in print editions of The Economist and the Folha de S. Paulo, a Brazilian newspaper. The stripes have even graced the catwalks of London Fashion Week and the uniforms of the UK football team Reading FC.

The stripes have been displayed on public infrastructure, including public transport in Europe, decorated buildings, and even natural landmarks such as the White Cliffs of Dover in England. Recently, they were showcased at a three-day music festival in Mexico City. The warming stripes have been used to adorn public transport such as electric trams and buses in countries including the UK and Germany. Cycling 4 Climate, a foundation that has organised rides in six countries to promote climate change awareness, chose the stripe pattern as a uniform due to the powerful message it conveys. 'It gives me the feeling that even when I'm exercising, I'm working on increasing climate change awareness,' says co-founder Joost Brinkman, based in the Netherlands. 'I frequently get asked about the shirt because people like the design. It's an easy conversation starter and people are always shocked when they understand the story.

Unlike traditional data visualisations, the blanket’s pattern only features colours – and resembles a barcode more than a normal graph. 'Some people switch off as soon as they see a graph, right? ' says Highwood. In her blog, she shared instructions to replicate the blanket using yarn or other materials. 'The craft version does something different. If you are physically reproducing the pattern, you are internalising the data, and there's more chance you'll feel that it's real. ' When Ed Hawkings, a climate scientist and professor at the same university, saw the climate stripes and witnessed people's reactions, he thought they would be a good way to visualise the data from climate change online. He reduced the range of colours to tones of blues and reds, universally associated in weather maps with temperature.