Air pollution in Nanjing, China
Photo: Let Ideas Compete via Flickr
Apr 2015

Why air pollution should be a top urban sustainable development goal and why an interdisciplinary approach is needed to solve the world’s largest single environmental risk.

This article was first published by UGEC Viewpoints. UGEC (Urbanization and Global Environmental Change) is one of the projects transitioning into Future Earth.

In 2012, the Organization for Economic Cooperation and Development (OECD) projected that by 2050 air pollution will be the top environmental cause of mortality worldwide, surpassing dirty water and lack of sanitation. However, the World Health Organization recently reported that in 2012 approximately 7 million people died as a result of exposure to air pollution, making it the world’s largest single environmental risk, 38 years earlier than projected by OECD. Many urban areas in both emerging and developed countries continually exceed the 2005 World Health Organization (WHO) Air Quality Standards. The map below shows urban areas that exceed the WHO standard for annual average PM10 of <20 µg/m3 (only the urban areas with green dots are meeting the WHO standard).

Increasingly international organizations are recognizing the risks associated with air pollution. The United Nations Environment Assembly in 2014 made improving air quality a top priority for sustainable development, recognizing that clean air is a priority to protect human health and has simultaneous benefits for the climate, ecosystem services, biodiversity, and food security. In response to the lack of air quality monitors around the world and the risk of air pollution exposure to US citizens, in February 2015 the U.S. Environmental Protection Agency (EPA) and the U.S. State Department launched an effort to install air quality monitors and the AirNow network, which provides real time air quality information, to diplomatic posts around the world. In his remarks on this effort, Secretary of State John Kerry stated he hopes this effort will “expand international cooperation when it come to curbing air pollution” and EPA Administrator Gina McCarthy stated “information and transparency empowers us to reduce health risks associated with air pollution”.

Increasingly air pollution is also one of the top social environmental justice issues. For example, air quality in Utah, USA is so poor that social movements such as Utah Moms for Clean Air and a Facebook group entitled “I have moved or am moving out of Utah because the AIR QUALITY is so crappy!” have been developed. The ties between urbanization and air quality have also spurred headlines such as “London, L.A., Beijing, Delhi, Nairobi . . . Is Smog an Inevitable Urban Growing Pain?”. Perhaps one of the most impressive indicators of air pollution being a social justice issue was a viral YouTube video entitled Under the Dome that had hundreds of millions of views. This hour and forty minute documentary by Chinese journalist Chai Jing investigated air pollution and air quality in China. The video was later pulled from Chinese video sites by the government in fear of an organized public uprising around the issue of air quality.

However, air pollution is often seen by the Global Environmental Change (GEC) research community as an old, and in many cases, resolved issue. The connection between urbanization and air quality remains largely unacknowledged within the scientific and policy communities. The general thought is that air pollution is uniform throughout the world and since the science behind the London Smog of 1952 and the poor air quality in Los Angeles, i.e., Smogtown, have both improved. Therefore, spending more time on the science behind how air pollution is formed and the risks and vulnerabilities associated with air pollution are believed to not be necessary. It is thought governments just need to implement technical measures such as particle filters on diesel engines or sulfur scrubbers on coal-fired power plants to improve air quality.

But we live in a changing world. Urbanization, economic development, energy choices, and policy decisions constantly change the amount and composition of air pollutants that are emitted into the atmosphere. There are still many physical and social science questions that remain regarding air pollution that must be addressed at the urban level. Do we understand the urban atmosphere and what components in air quality cause the greatest impact on human health? How will changing energy sources impact urban air quality and what will be the impact of changing technologies on urban air quality? Why does air quality have to get so poor before action is taken by governments and what are the social, technological and ecological factors that influence exposure and vulnerability to air pollution?

Perhaps one of the most interesting questions to address is, could urbanization occur in such a manner that air pollution could be mitigated via non-technical measures, e.g., walkable cities, rather than the traditional manner of cleaning up air quality via technical measures after air quality becomes a social environmental justice issue? For example, green space in urban areas is often considered desirable. However, the type and placement of the vegetation can have significant impacts on air quality. In urban planning many factors are considered such as affordable housing or connectivity to the electric grid, but rarely is air pollution one of those factors. It is possible to improve air quality by looking at how meeting urban development priorities impact air quality before they are implemented.

There is an incredible opportunity to reduce the risks associated with exposure to air pollution by making air quality an integral component of sustainable development, especially in the urban areas. To address urbanization and air quality requires an interdisciplinary group of social scientists, engineers, urban planners, physical scientists and policy makers to investigate multiple research questions. Air pollution research and policies should be adapted to the physical, economical, political, and social contexts within each region to best deploy scarce financial, technological, and human capital. It is only through an interdisciplinary approach to air pollution that we can prevent the air we breathe from being the number one environmental cause of mortality worldwide while also achieving simultaneous benefits for the climate, ecosystem services, biodiversity, and food security.