A wide variety of policy approaches, including but not limited to planning regimes, emissions and technology standards, market interventions, public information and international cooperation, have been applied to the problems of air pollution, climate change, ODSs and PBTs. Lessons can be learned about each type of policy approach from applications to the four different problems at different geographical scales.
One lesson is that policy approaches must be adapted to specific contexts. There is no single model policy that is most appropriate for all settings. High-income countries rely on information-rich planning regimes and regulatory approaches backed by government enforcement capacity. These approaches may not be the most appropriate for settings where information is poor and enforcement capacity is lacking. In such settings, voluntary standards, market
interventions and public information may prove more effective in decreasing emissions and hazardous exposures. To improve the effectiveness of such attempts to strengthen climate finance and reduce air pollution, development assistance will play a crucial role in capacity-building and green economy development. Capacity-building should focus on strengthening the technical and planning capabilities at local and national levels that are most relevant for anticipating the potential impacts of climate change and developing appropriate policy responses. Air quality measures need to be combined with climate and energy measures, agricultural policy, transport policy and urban planning, with a focus on improving health and biodiversity. A key message and challenge is how to ensure that climate policies do not increase health risks (e.g. from biomass burning and diesel) and that air quality policy is climate neutral. Also, it is imperative to consolidate a multi- scale governance approach that aligns international, national and local actions (Maas and Grennfelt eds. 2016).