A record-breaking heatwave in France this summer was a reminder that global warming is already with … [+]
A staggering three quarters of the world’s population will be at risk from extreme heat as the planet warms, causing skyrocketing demand for air conditioning and requiring massively more energy generation. Yet plans to cope with this need are being largely ignored by richer countries with generally cooler climates, where most research bodies are based.
That’s one of the conclusions of a new report from the University of Oxford, where a team has been looking at the human need to stay cool.
The researchers found that only a fraction of studies addressing climate change have looked at air conditioning, and highlighted some startling facts about what it will take to deal with our hotter future. Over the next 30 years, two to four billion people will need air conditioning installed in their homes to avoid health risks such as heatstroke. This will mean 10 air conditioning units will need to be installed every second until 2050. In turn, this will produce a tripling of energy demand, all while nations attempt to reduce emissions and strive towards energy efficiency.
“The world is at the brink of unprecedented cooling demand,” say the authors of the study, published yesterday in Nature Sustainability, noting a vicious cycle of global warming in which “increasing extreme temperatures are changing global requirements of thermal comfort, increasing GHG [greenhouse gas] emissions.”
Despite this threat, the researchers found that “studies on heating buildings are orders of magnitude more numerous than those of cooling them.” This focus on heating, the researchers say, means cooling has been largely ignored in the UN’s sustainable development goals (SDGs), which are intended to reduce poverty and inequality while tackling climate change.
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But overlooking the importance of cooling, the paper notes, undermines those goals. Inefficient and poorly built air conditioning systems, along with unsustainable manufacturing of those systems, will lead to a far greater energy demand than necessary while creating additional waste, pollutants and environmental harms.
On the other hand, in their study of thousands of peer-reviewed papers, the team concluded that implementing sustainable cooling could help hit all of the sustainable development goals, “from energy and sustainable cities, to gender equality and the elimination of poverty.”
Speaking to Forbes.com, the report’s lead author suggested climate work had had a bias towards more prosperous countries in the global north, meaning the issue of cooling had been neglected. Radhika Khosla, principal investigator for the Future of Cooling Programme at Oxford Martin School and senior researcher at the Smith School of Enterprise and the Environment, said:
“There has been a historic emphasis on heating for the provision of thermal comfort for societies, which is tied to much of the research literature being rooted in colder and developed country climates. The geography of cooling looks very different and focuses on countries with warmer climates.”
Khosla also explained that, while countries such as the U.S. and Japan have typically dominated the market for air conditioning, the demand among less prosperous countries was now increasing.
“Many of these countries that will require cooling are entering into their development phase for the very first time,” she said. “A just transition requires a decent quality of life for all people—in this specific case, it would mean access to cooling for all.”
Rather than focusing solely on technological or policy answers to the challenge of providing cooling, the researchers set out a multidisciplinary framework for how to make such a transition possible, identifying five “levers”—social interactions, technology, innovation, business models, governance and infrastructure design—to drive sustainable change.
The researchers noted major social differences in how people react to heat, from the types of clothing people wear to the beverages they drink. Those differences can also be national in scope: “Cooling-related lifestyles vary,” the report finds. “The average U.S. American consumes over six times the energy for space cooling compared to people in the European Union, and over 28 times compared to people in India … In Singapore, the use of ACs is deeply rooted in everyday practices, while in Japan, despite most households having AC, people prefer natural ventilation.”
For this reason, the authors say, “a deep understanding of cultures and household dynamics is central to driving such sustainably oriented behaviours.”
The paper suggests a number of routes by which low income regions can improve the affordability and sustainability of cooling, including “cooling as a service” (CaaS) business models. Rather like a subscription service for air conditioning, CaaS businesses provide the air conditioning system and the user pays a service fee, removing the large upfront cost of the air conditioning unit itself.
Among the technological answers to the cooling problem, the researchers cite the effectiveness of passive cooling solutions for homes, emphasizing the need for housing designs with better natural ventilation, as well as windows that use “phase-changing” materials, allowing light in but effectively blocking out heat.
The paper also notes that in cities, increasing vegetation through urban tree planting, green façades and green roofs can lower urban temperatures.
Crucially, Khosla said, every answer to the cooling question will need to be sustainable, with a low or zero-carbon impact, or risk exacerbating the situation further.
“The global community must commit to sustainable cooling, or risk locking the world into a deadly feedback loop, where demand for cooling energy drives further greenhouse gas emissions and results in even more global warming,” she said. “At this critical juncture in global economic development, including in building back better from Covid-19, there is a unique and fleeting opportunity to centre sustainable cooling for the benefit of people and planet.”
