A pioneering team of scientists has developed a new method to visually track and compare air pollution levels worldwide, revealing striking inequalities and offering a beacon of hope for improvement. Their innovative approach, dubbed “air quality stripes,” charts pollution data from 1850 to the present day, making the invisible issue of air pollution both visible and understandable.
Inspired by Ed Hawkins’ climate stripes, these air quality stripes use a color-coded system to represent yearly pollution levels. Each year is displayed as a vertical bar, with colors ranging from sky blue indicating air that meets World Health Organization (WHO) guidelines to darker shades of yellow, brown, and black for increasingly polluted air. The color scheme reflects over 200 images of smog from around the globe, vividly illustrating the changes in air quality over time.
Dr. Kirsty Pringle from the University of Edinburgh, a co-director of the project, highlighted the significance of this visualization, saying, “Air pollution is often called the invisible killer, but these images make the invisible visible, showing the changes over the decades.”
The new tool allows users to generate customized air quality stripes for major cities around the world. Dr. Jim McQuaid of the University of Leeds, another co-director, emphasized the project’s impact: “It’s all about that lightbulb moment when someone understands the data; that sudden ‘oh yeah, now I get it’.”
The stripes reveal significant improvements in cities like London and Beijing. London, once notorious for its coal-induced smogs, experienced dramatic air quality improvements following the introduction of clean air legislation in the 1950s. Beijing, which faced severe pollution leading up to the 2008 Olympics, has seen rapid progress due to recent efforts to clean up industry and traffic.
In contrast, cities such as Jakarta and Islamabad highlight the challenges faced by many developing nations. Rapid urbanization and industrial growth in these areas have outpaced the implementation of effective air pollution controls.
The data used to create these stripes comes from global climate models provided by the UK Met Office, combined with satellite observations available from 1998. This data, though challenging to model accurately, has been adjusted to offer a comprehensive view of historical and current pollution levels.
Despite these improvements, over 99% of the world’s population still breathes air that does not meet WHO guidelines. In Europe alone, particle pollution contributes to over 400,000 early deaths annually, with the UK accounting for 29,000 to 43,000 of these fatalities.
Prof. Ed Hawkins, creator of the climate stripes, emphasized the broader implications of visualizing data: “The climate stripes have appeared in various high-profile contexts, and by making abstract data tangible, we can all play a part in addressing some of the world’s biggest issues. While many cities continue to struggle with poor air quality, the improvements seen in others demonstrate that significant change is achievable with sufficient political will.”
This new visualization tool not only highlights the global disparities in air quality but also underscores the potential for positive change through concerted action.