In the breach: feeling the heat of climate change

The increased likelihood of extreme heat events is a profoundly important aspect of our global climate emergency, and yet the link between weather and climate remains a difficult subject to communicate. Here, I focus on a graphic that is on its way to becoming viral: Warming Stripes. Warming Stripes use a simple two-colour spectral palette - tints of blue and red, long a feature of weather maps - to signal relative yearly temperatures. Eschewing the argument that such hues have a universal affective capacity, and reflecting on its designer's comments on the potential introduction of a new colour, purple, to indicate extreme heat, I argue that it is as a constructed, learned association between temperature and colour that there is further potential for this visual to intimate a warning. That is, while the potential introduction of purple signals a breach regarding accustomed climatic conditions, what is also breached is our capacity to maintain a standard of measurement by which to capture such conditions. I expand on this argument via reference to a prior of just such a breach, as a forecasted heatwave prompted the Australian Bureau of Meteorology to introduce a new colour to the hot end of its temperature scale: purple.