After a summer of deadly heat, the future of air conditioning in a world marked by rising temperatures has come sharply into focus. While some research has indicated we could “essentially cook ourselves” if the world collectively turns on the air conditioning in the face of more extreme heat, a new study shows the reality may be slightly different. And in some ways, the findings are even more worrisome.
In a study published on Wednesday in Nature, a team of researchers from the Climate Impact Lab, a collaboration between climate economists from various institutions, set out to determine just how much household energy use has increased and will increase due to climate change. The findings show the stark inequalities in future energy use for heating and cooling. The world’s richest residents, they found, will benefit from saving on heating during the winter, while the rest of the world will struggle without access to air conditioning during hot summers. Middle income countries, meanwhile, could see spiraling energy burdens as they struggle to cope with extreme heat.
To do the maths on how energy consumption will change, researchers first collected 40 years of energy use datasets from 146 countries, as well as data on historical weather trends, and then measured how energy consumption in different areas changes with extreme temperatures. This holistic approach offers a rare glimpse of true heating and cooling energy use around the world.
“In prior work, researchers often extrapolated what would happen in poorer regions by looking at research from richer regions,” Amir Jina, an assistant professor of public policy at the University of Chicago and a coauthor of the study, wrote in an email. “So, for example, they’d take information on how temperature affects AC use in the very wealthy U.S., and apply that to much less wealthy India. This might overstate energy-related costs of climate change, because you’d assume that every Indian household would just switch on their AC when it gets hot and would consume a huge amount of energy. But we know that most households in India don’t have AC units, so if you don’t include data on India or other less wealthy places, you get the answer wrong.”
The birds-eye view shows that in wealthy locations, wealthier people — especially the top 10% — turn up their air conditioners, making electricity use per person skyrocket. But there’s scant little corresponding increase in individual energy use in poorer areas even as the temperature increases.
The researchers then divided the world into more than 24,000 different regions, based on existing administrative divisions or groups of administrative divisions within country borders such as U.S. counties. They then made projections about energy use in the future, using different emissions and economic scenarios to project these impacts.
By the end of the century, areas in India, Indonesia, and Mexico — which don’t have high air conditioning use now — will use dramatically more electricity for cooling as they figure out how to deal with rising temperatures. In India alone, energy use is expected to increase by nearly 145%. The dramatic uptick in electricity consumption in these countries isn’t just due to rising heat, though; they’re also among countries where economic growth will make air conditioning more accessible to a greater part of the population. Other countries will see largely climate change-driven increases, including a staggering 2,086% increase in electricity consumption in Nigeria. Wealthy countries like the U.S. will also see an uptick in electricity use for cooling, but it will be relatively modest percentage-wise at just 3% given the high penetration of cooling technologies already.
The research also shows that fewer colder days means the world will use less heating fuel, so much so that it will offset changes in electricity demand. The study is part of the Climate Impact Lab’s effort to effort to figure out how climate change will impact economies and lives at the local level across the world, in order to more accurately provide an estimate for the social cost of carbon (or SCC in economistspeak) — the economic cost of emitting one ton of carbon dioxide into the atmosphere today, a metric used around the world.
The findings show that the part of the SCC tied only to heating and cooling is in the negative, somewhere in the -$US3 ($4) to -$US1 ($1) range. That means in purely economic terms at the global level for heating and cooling, rising temperatures are Fine. But Fine Globally for heating and cooling is not the metric that really matters here. The study shows the biggest cost savings will be in the richest countries, which are largely located away from the tropics. Those countries will use less energy for heating as winters warm up. Poor countries — most of which are located in the tropics — will have to figure out how to deal with more heat and more cooling demands on the grid.
“The economic impact of warming on global energy consumption is modest,” Jina said. “Despite that small net effect, though, the inequality across the world is enormous — we see places that benefit because they don’t have to spend as much on heating but don’t get hot enough to need a lot of AC, places that get hot but are wealthy enough to afford AC, and places that get really hot but just don’t get rich enough, even by the end of the century, to have widespread access to cooling technologies. Again and again, we are seeing that this stark inequality is a feature of climate change.”
This raises an enormous set of questions raised about equity and energy access around the world, both now and in the future. Countries like India, with that projected 145% energy increase, are going to have to figure out how to adapt their electricity system to a hotter world. These countries — and the most vulnerable populations who call them home — have played relatively minor to no role in causing the climate crisis.
The SCC is much more than what shows up on your electric bill each month. Previous research, including some by the Climate Impact Lab, shows that damages from the climate crisis will be extreme. The small offset in the energy SCC will be dwarfed by the loss of life from extreme heat, infrastructure destroyed by rising seas, and more.
“There’s an enormous amount of differences across space and climates in how people are affected,” Jina said. “If we care at all about this inequality in impacts, we need to have as much information about the differences across populations as possible.”