Joy Division climate chart by BBC News

The year 2023 has been confirmed as the warmest on record, breaking the previous record set in 2016. This temperature record was driven by human-caused climate change and boosted by the natural El Niño weather event. Each January, global climate data providers publish new updates to their various bar and line charts to highlight the continued warming of the planet. But 2023 was an exceptional year in which multiple records were broken, and we wanted to highlight how unusual it was in a single powerful visual.

Despite being a static graphic, this ridgeline chart conveys dynamism - the steady warming of our climate, year after year. Using the ggridges R package, we built for each year since 1940 (the full extent of the available record from the European Copernicus Climate Change Service) a density histogram of the daily temperature deviations, or anomalies, from a 30-year reference period (the international standard, 1991–2020).

The result is a unique data visualisation inspired by the Climate Stripes visualisation from Prof. Ed Hawkins, and the iconic Pulsar Chart that was featured on Joy Division’s Unknown Pleasures album cover. The double encoding - using both left-to-right positioning and blue-to-red divergent colour gradient - helps the reader clearly understand the visualisation, seeing the climate change trend in colour and position, and how much 2023 stands out compared to other years.

To enhance accessibility, a simple “How to read the chart” section at the bottom of the chart ensures that every reader has all the keys to understand this chart, as this is a new and unconventional way to visualise this data. Additionally, key years - 2023 and two other record-breaking years - are annotated to draw attention to important sections of the chart.

This innovative data visualisation aims to bring a new perspective, moving beyond the repetitive use of bar charts of temperature data that often leave readers feeling disengaged. By presenting the data in a novel and thought-provoking format, the chart seeks to re-spark discussions about climate change, encouraging a deeper connection to the issue and inspiring renewed urgency in addressing this global crisis.

This new visual representation of climate change became viral on social media, and was used widely by scientists, researchers and climate experts. The online piece was very well received, exceeding our engagement targets for younger audiences. A new similar version has been created and published recently following a new record-breaking year: 2024.