The Climate in Emergency

A weekly blog on science, news, and ideas related to climate change

It’s HOT!

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Ok, it’s cooling down slightly now, but according to our home weather station, the high of the day was 93 degrees Fahrenheit. In the shade. The heat index reached 110 degrees, likewise in the shade. And we have not used the air conditioner.

No, we are not masochists. We actively manage the temperature inside our house by closing windows and drawing blinds, and it’s been at least ten degrees cooler indoors for most of the day–the temperature’s starting to climb in here now, we’re at 85 degrees, but fans and the option to take a cold shower make it bearable. In a few hours, when the outside temps come down, we’ll open up the windows and doors and cool down the house again and I will go for a walk. We put off vigorous physical activity, or anything that could heat up the house, like cooking, until the evening.

People used to live like this, adjusting daily activity levels to cope with the heat and using architecture, such as high ceilings, thermal mass, or, as in our case, excellent insulation, to keep living spaces as cool as possible. In some communities, in some parts of the world, such methods are still the standard. All our neighbors, on the other hand, seem to be running their air conditioners.

Air conditioners are a problem.

Not only do air conditioning systems use a lot of electricity–about 20% of US residential electrical consumption goes towards air conditioning alone. Even more seriously, the coolant inside air conditioners is a very serious greenhouse gas, sometimes thousands of times more powerful than carbon dioxide.  I want to go through that part in more depth, because it can be confusing.

Air conditioners (and refrigerators and freezers) work on the principle that the temperature of a gas is related to its density. These machines all feature a closed loop of some kind of gas. At the beginning of the cycle, the gas is compressed, making it hot. The hot gas then flows through a radiator-like coil, where it cools off (and condenses into a liquid). Then it is re-expanded–and now it’s much cooler. The process is something like wringing out a dish towel, squeezing the water out so that when the cloth expands again it carries much less water. The cooled gas then pulls heat out of the room (or out of the refrigerator) and then goes through the cycle again. The coolant itself could be any of several different kinds of gas, but for decades chlorofluorocarbons (CFCs) were the standard because they’re non-toxic. Unfortunately, they are also greenhouse gasses and ozone-layer eaters.

When CFCs’ role in ozone depletion was discovered, the world stopped using them, as per the Montreal Protocol, although some CFCs lingered in older machines. They were replaced by HCFCs, which were less dangerous for the ozone, but worse for the climate. HCFCs were then replaced by HFCs, which do not damage the ozone at all, but are still very bad for the climate. The problem is that the Montreal Protocol only protects the ozone; there is no equivalent to protect the climate and thus no legal mechanism to limit the use of HFCs.

One complicating factor is that all of these chemicals can be called Freon, a brand name that covers multiple chemicals. So it’s easy to hear a lot of conflicting stories on whether Freon has been banned or not; the truth is that some Freons have been and others have not.

Refrigerant systems do not vent coolant when they are functioning normally; running your air conditioner does not release the gas. However, systems can leak. Worse, once the gas is created, it will almost certainly get into the atmosphere eventually. Freons don’t biodegrade, so no matter how much time goes by, they are still a threat to the climate. Choosing not to run your air conditioner, as we do, does not actually help with Freon. Only not getting the machine in the first place does that. But not running the air conditioner does cut down on electricity use, and that matters.

Climate-neutral refrigerants do exist, but have not yet won regulatory acceptance. There are cooling systems advertized as “green,” but usually because they use less electricity. That matters, too, but efficient air-conditioners, refrigerators, and freezers still contain those powerful greenhouse gasses. Keeping those systems in good repair, so that they do not leak, is important, all of this, efficiency, preventing leaks, everything, is all about making a situation less bad. Only switching to climate-friendly coolants–or giving up the machines–will solve the problem.

For individuals, efficient machines are a good intermediate step, but for society, they are a drawback. For one thing, the more efficient machines get, the more people use them–often resulting in even more electricity use. For another, cheap air conditioning leads to dependence on artificial coolness. For example, huge numbers of elderly people have retired to sun-belt cities. Not only is this demographic more vulnerable to heat-related injury and illness, but those cities have been developed with air-conditioning in mind–without architectural and community-planning details known to bring down the heat, like high ceilings, good night-time ventilation, and community green spaces. The result is a series of intense heat-islands filled with people who need air conditioning as a matter of life and death.

So what’s the value of an individual family, like ours, going without air conditioning on a day like today?

It does reduce electricity use, sometimes a lot. Just as important–or maybe more importantly–it’s a good way to remember that air conditioning really isn’t necessary much of the time, a way to remember that we as a society can turn the machines off, except for occasional therapeutic use. If going without air condition seems difficult, just remember–by turning on the chillers we’re actually making our days even hotter.

Indoors and outdoors, the temperature is now 86 degrees–outside, the temperature is falling. It’s time to open all the windows and doors.



Author: Caroline Ailanthus

I am a creative science writer. That is, most of my writing is creative rather than technical, but my topic is usually science. I enjoy explaining things and exploring ideas. I have one published novel and another on the way. I have a master's degree in Conservation Biology and I work full-time as a writer.

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