Air quality and climate change are two very closely linked environmental problems. Many air pollutants that are toxic for human health are also greenhouse gases (GHGs) or GHG precursors. Additionally, the warming climate may increase chemical reaction rates, making smog in cities worse. The International Global Atmospheric Chemistry (IGAC) Project working under the umbrella of the International Geosphere-Biosphere Programme (IGBP), released a statement on March 27th at the Planet Under Pressure Conference in London, on their new Air Pollution and Climate Initiative . This initiative aims to engage scientists, economists, and policy makers to “assess the status of knowledge with regard to current understanding about air pollution and climate and their interactions, in particular with relation to current and proposed mitigation options and policy discussions” .
Their report, titled “Time to Act: The Opportunity to Simultaneously Mitigate Air Pollution and Climate Change” summarizes the linkages between air pollution and climate change, and emphasizes that a multidisciplinary approach is essential if society wants to slow the rate of climate change and protect human health, food and water security, and ecosystems.
It is a complex problem, because some air pollutants such as sulfur dioxide (SO2) have a cooling effect on climate. There are already actions currently taking place to control this pollutant (which is good for protecting the environment and human health), but without simultaneous action to control GHGs, such as long-lived carbon dioxide (CO2), we will end up exacerbating global warming by removing only the cooling gases. 
Some measures to reduce GHGs include switching technologies or fuels. These changes may increase or decrease air pollutants depending on which are chosen. Therefore, by considering both air quality and climate change when we mitigate GHG emissions, we can have win-win solutions that benefit both environmental problems. 
IGAC recognizes that the solutions to air quality and climate change involve policies from all levels of government, and that there are many social considerations to into account (e.g., economics). However, policy makers need a sound scientific foundation to play an integral role in developing those solutions.
IGAC and IGBP’s next step will be to release a Strategic Plan for an interdisciplinary programme to address air pollution and climate change in the Autumn. Their plan will focus on some key areas, such as urban development and agriculture where an interdisciplinary approach will be very beneficial.
 IGBP/IGAC (2012). Time To Act: The Opportunity to Simultaneously Mitigate Air Pollution and Climate Change. International Geosphere-Biosphere Programme (IGBP) and International Global Atmospheric Chemistry (IGAC) Project, 6pp.
blog post by Cyndi Whaley