Comfort That Warms the Planet
It’s a paradox at the heart of our fight against climate change. Air conditioning—an essential technology that protects millions of people from deadly heat waves—is itself contributing to global warming. A new study sheds light on this vicious cycle, revealing how our need for cool air could have far more serious consequences than expected.
A World Already Under Thermal Stress
The initial finding is clear-cut. Human activities have already warmed the Earth by about 1.2°C compared to pre-industrial levels. This increase, which may seem modest, results in more intense and frequent heat waves. Between 2000 and 2019, nearly half a million heat-related deaths were recorded worldwide. Air conditioning is a direct solution to reduce these risks and protect the most vulnerable.
At the same time, the market has exploded. Global sales of air conditioners quadrupled between 1990 and 2016. China and the United States alone account for more than half of global sales. The logical consequence: the amount of electricity consumed for cooling has more than tripled since 1990. Since the majority of electricity still comes from fossil fuels, we’ve come full circle: for now, more cooling means more carbon emissions.
Projections That Make Your Head Spin
In numerical terms, this translates to a proliferation of appliances. The world could have approximately 2.3 billion air conditioners by 2050 under this median scenario. But if our dependence on fossil fuels increases, that figure could climb to 3.1 billion units. Electricity consumption would follow the same trend: it could reach 4,493 terawatt-hours under the median scenario, and even exceed 12,000 terawatt-hours in the highest-emission scenario, representing nearly 15% of the building sector’s total energy consumption.
Income: The Main Driver of Air Conditioning Use
The study reveals a crucial point: it is above all rising incomes that explain the increase in air conditioner use, far more so than simply rising temperatures. Professor Yuli Shan of the University of Birmingham explains: “Global warming is raising temperatures and causing more heat waves, and as economic growth progresses in some of the hardest-hit countries, more people are able to cope with extreme heat through air conditioning.”
This mechanism traps us in a sort of arms race. “As global temperatures rise, we risk being locked into an ‘arms race’ where defending ourselves against extreme heat actually exacerbates the problem,” Professor Shan continues. According to calculations, in the median scenario, emissions from air conditioning could reach 3.8 gigatons of carbon dioxide equivalent per year by 2050. In the most pessimistic scenario, they could rise to 8.5 gigatons—equivalent to the United States’ current annual emissions. Between 2010 and 2050, total emissions from air conditioning could exceed 100 gigatons in this same median scenario.
A Climate and Social Time Bomb
The direct impact on global temperature is quantifiable. These emissions could contribute approximately 0.05°C to global warming by 2050 under the median scenario, and up to 0.07°C in the worst-case scenario. While these figures may seem small, they are significant given that the planet has very little leeway to remain below the 1.5°C target. Added to this is the growing problem of refrigerant leaks—gases that are often far more potent than CO₂ at trapping heat—which could account for a significant portion of air-conditioning-related emissions by 2050.
Demand for cooling is highest in equatorial regions such as Southeast Asia, South Asia, and parts of Africa. However, many of these regions have lower income levels and limited access to air conditioning. Researchers estimate that there could be a shortfall of 94 million air conditioners in low-income regions by 2050. If these regions were to reach high-income levels, this “cooling deficit” could rise to 150 million units. Dr. Hongzhi Zhang of the Beijing Institute of Technology warns: “The study reveals that if all low-income regions were to gain the same access to air conditioning as wealthy regions, global emissions related to cooling would increase dramatically—adding up to 0.05°C of additional warming even in the most climate-friendly scenario.”
How can we break this deadlock?
Simple actions can also make a difference. Raising the thermostat setting during peak hours can reduce electricity demand by up to 20%. Public awareness and the adoption of energy-saving habits play a significant role. For Professor Shan, the path forward is clear: “The world must quickly transition to cleaner and more efficient cooling technologies—while ensuring equitable access to cooling, particularly for vulnerable populations.” Air conditioning will remain essential. The challenge is to make it accessible to everyone without fueling the very crisis it is meant to combat.
Source: earth.com
Air Conditioning: The Technology That Saves Our Lives and Accelerates Global Warming
