For every viral image of overflowing passengers crossing an ocean or families packed into tents in a refugee camp, there are millions more people, unphotographed, experiencing the same suffering.

On Friday, the Initiative on Cities partnered with the Department of Environmental Health and the Frederick S. Pardee Center for the Study of the Longer-Range Future to host a talk entitled “Air Quality Data to Action: Case Studies and Strategies from New York City and C40 Cities.”