On the Brink: Urban air quality – how did we get here?

Over the past 15 years, the international community has taken a series of positive steps in joining the dots on climate change, air quality and the built environment. I want to focus here on five important stages of the conversation, which I will list in reverse chronological order. Doing it this way will, I hope, better demonstrate the manner and speed at which the discussion has evolved.

In January 2020, the World Economic Forum held its first hybrid in-person/virtual annual meeting. 3000 participants from around the world assembled logged-in to discuss “stakeholder capitalism” – an increasingly fashionable but still somewhat slippery concept. They sought consensus on how governments and institutions could more accurately track progress towards the Paris Agreement and UN Sustainable Development Goals. This was a giant leap in the right direction: targets are easy to set, but without clear and collaborative leadership, they are much harder to achieve. That much is true even of relatively modest targets; there is, of course, nothing at all modest about the emissions agenda. In a growing number of territories, greenhouse gas (GHG) emissions caused by work in the built environment are capped by law. We are moving incrementally towards a global policy consensus on decarbonisation.

2019 saw the declaration of a global climate and biodiversity emergency. Signatories included the World Green Building Council, C40 Cities and numerous professional bodies. The centrepiece of the declaration was the Net Zero Road Map, by which cities can navigate their way to a cleaner, greener more equitable future.

C40 Cities published research in 2018 suggesting that targeted action on clean transport, buildings and industry, alongside the decarbonisation of power grids, could seriously drive down GHG emissions. A 49% reduction in particulate matter 2.5 (PM2.5) levels could save 223,000 premature deaths each year, not to mention hundreds of millions of dollars.

The World Air Quality Index was launched in 2007. This non-profit project has established the first ever comprehensive global monitor of air quality data. Its ongoing mission is to spread public awareness of air pollution and provide unified and worldwide air quality information. At present the monitor provides transparent, quality-assured information on more than 2000 cities in 130 countries. This was the first time that citizens had been granted access to reliable, open-source data on the intersection between urban health and climate change.

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.