Rethinking air conditioning amid climate change

More than 30 years ago, all of the world's countries agreed on something for the first time in history. They signed on to the Montreal Protocol to phase out chemicals that damage the ozone layer. The cooling and refrigeration industry uses chlorofluorocarbons and hydrochlorofluorocarbons. HFCs were quickly found.

Scientists have come to realize that the Montreal Protocol may have traded an immediate problem for a long-term one. Though HFCs don't cause the same damage to the ozone layer as CFCs do, the chemicals have warming potentials hundreds to thousands of times higher than that of CO 2 making their growing global use a cause for concern.

The air-conditioning and refrigeration industry boomed in Europe and North America during the 20th century. China, India, and Nigeria are all seeing a surge in demand for these appliances.

According to a 2020 report by the United Nations Environment Program, there are 3.6 billion cooling appliances in use today, and the number is expected to leap to 9.5 billion by the year 2050. If everyone who needed cooling services could get them, that figure would be 14 billion.

Shelie Miller is an environmental engineer at the University of Michigan. The rising global demand for cooling and refrigeration was examined in an article by Miller in the Annual Review of Environment and Resources. The conversation has been edited for clarity and length.


This may seem odd to a lot of people. Why should we be worried about the cooling and refrigeration industry?

It's rare that people think about cooling services when they think about environmental impacts. It is an important issue that isn't being addressed. It intersects the building, transportation, and food sectors. It has a huge impact on global energy use and greenhouse gas emissions.

The industry is going to see a lot of growth in developing countries. It's important that we understand the industry's impact.

How does the industry affect the environment?

The amount of energy it takes to cool an environment is enormous. Our electricity grids rely on fossil fuels and any energy use that goes to reducing temperature also emits greenhouse gases. Fossil fuels account for a lot of the environmental impact.

Refrigerants are required when we talk about the technology of cooling spaces. Refrigerants are chemicals that are used to reduce temperatures.

Even though we use a relatively small amount of refrigerants, the impact of their leaking out into the atmosphere ends up having a major impact on the climate.

HCFCs had a devastating impact on the ozone layer. We introduced new chemicals after banning them. Did we only have problems here?

The ban of certain chemicals that are ozone-depleting is one of the great environmental successes. The Montreal Protocol banned the use of ozone-depleting chemicals in the refrigerant industry. We came up with HFCs as replacements. That did a great job of reducing ozone depletion, but at the cost of warming.

Ozone depletion potential was traded for high greenhouse gas emissions. Nations are trying to tackle the greenhouse gas emission associated problems with the use of refrigerants. We are trying to find alternative refrigerants that have a lower global warming potential.