Beyond the thermostat: Critically reviewing the scientific evidence for global cooling and air conditioning demand

Driven by the specter of climate change and growing concern over extreme heat events, research into future space cooling demand has grown, mostly focusing on weather-dependent use. Alarmingly, increased carbon emissions from air conditioning alone could be almost entirely responsible for an additional 0.5 °C increase in global temperature. Strengths within the scientific evidence on cooling demand include spatial granularity as well as temporality in projecting reliable scenarios beyond the midcentury. As this literature has evolved, however, it has become fragmented and prone to shortcomings including assessments that disconnect energy demand and the built environment from nature-based solutions, assessments that frequently ignore resilience, and biases in technology selection that may exacerbate injustice and vulnerability. To assess findings across this literature and establish future research priorities, this study offers a critical, umbrella review of the scientific evidence to assess key themes and considerations in study methods. The study reveals a wide range of geographical scopes and temporal variation among studies which broadly confirm the conclusion that tropical regions will experience the most absolute weather-dependent demand while other regions will experience higher relative demand changes. Beyond this, establishing more realistic assessments of energy and cooling demand remains elusive, and the authors suggest that a future research agenda should make progress toward this understanding by studying a range of behavior- and built environment-related determinants of demand to better support future planning and occupant health outcomes, including perspectives from “critical geography” that endorse a “political ecology of air” centering on neglected aspects such as thermal justice, cooling poverty, and the political economy of heat exposure.