In 2005, then-Mayor of London Ken Livingstone convened representatives of 18 megacities to forge an agreement on cooperatively reducing pollution. And so was created the C20, later to become the C40. This group now numbers 97 cities across the globe. Together, they compile evidence-based case studies on climate mitigation and associated issues – including public health.
I believe that my reverse chronology tells us two things. On the one hand, it proves that good intentions do produce good actions. The ball that started rolling in 2005 has picked up real speed in recent years. On the other, it starkly illustrates how long it has taken us to get here and, crucially, how much work remains to be done.
The global climate challenge and the air pollution problem are inextricably linked. Actions designed to tackle GHG emissions will positively impact the liveability of cities, the wellbeing of their citizens, and overall levels of growth and prosperity. Dr. Diarmid Campbell-Lendrum, who lead the World Health Organization’s (WHO) delegation at the Bonn Climate Conference in 2018 perhaps put it best.
“We have a unique opportunity to get these two things, climate change and health, right – if we get air pollution right”, he said. “The health benefits of climate mitigation will pay for the costs of climate mitigation.”
By combining WHO guidelines with data from the World Air Quality Index, we are able to paint a picture of the true situation. It is not pretty. Levels of atmospheric PM2.5, the most commonly measured air pollutant, exceed WHO limits in most cities. Virtually all of the world’s urbanised population is exposed to dangerous levels of air pollution.