Adaptation to a warmer climate invariably includes the increased use of indoor air conditioning. This behaviour is not without potential consequences, although many of the impacts remain underexplored.
David Abel and colleagues from the University of Wisconsin-Madison, USA, assess the health impacts of increased air conditioning where the power sector remains carbon-intensive by linking multiple models to simulate interactions between future weather, building energy demand, power sector emissions and air quality for the eastern United States. Using meteorological conditions and electricity demand for July, they estimate that in a warmer climate, 3.8% of the overall increase in particulate matter and 6.7% of the total increase in ozone may be attributable to increased use of air conditioning. Consequently, 5–8% of air-pollution-related mortality, and comparable proportions of other health impacts, are similarly attributable.
The authors are clear that this is only one possible scenario of the future, and further work is needed. Nevertheless, the study serves as a warning that adaptive behaviour such as use of air conditioning, while necessary to manage human health impacts, can have substantial air pollution impacts if the power sector is not decarbonized.