Climate change could drive air conditioning to boost carbon emissions

The climate is full of feedback loops. When a warming climate melts sea ice, the water that's left behind reflects far less sunlight, leading to a further warming. Now, some researchers at the University of California Berkeley have looked at a human feedback loop: the relation between climate change and air conditioning. Using Mexico as an example, they find that the rising use of air conditioning may boost the country's electricity use and carbon emissions by 80 percent before the century is over—but only if economic growth continues at a pace that allows people to buy air conditioners.

Understanding the margins

The study involves combining two types of economic figures, the intensive and extensive margins. Intensive margins, in this case, focused simply on what happens to electricity use as the temperature goes up. Here, the authors took advantage of the complete household-level billing records of 25 million residential electricity customers in Mexico. That data was cross-correlated with local temperature data.

Mexico contains everything from high-elevation deserts to tropical forests at sea level, so customers are exposed to a range of climate conditions. The authors found that electricity use remained relatively flat until the temperatures reached about 24 degrees Celsius (75 degrees Fahrenheit), after which they rose to the point where each day of the month with temperatures at or above 35 degrees Celsius (95 degrees Fahrenheit) boosted electricity use by 3.2 percent.