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The Environmental Impact of Air Conditioning

by Larry Carley copyright 2021

I just finished reading a book called After Cooling by Eric Dean Wilson, published by Simon & Schuster in 2021. The book is mostly about the environmental impact air conditioning and refrigerants have had on the Earth's protective ozone layer, global warming, climate change and our everyday way of life. It is a sobering read to say the least, but well worth the time it takes to plow through 408 pages of facts, figures, social commentary and the author's opinions about how air conditioning has reshaped the world we live in and what lies ahead.

After Cooling book

The book is divided into three major segments: Before Freon, The Age of Freon, and After Freon.

Freon, by the way, is the DuPont Corporation trademark name for a refrigerant called "dichlorodifluoromethane", which we know as R-12. It is part of a family of chlorine & fluoride based refrigerants known as "chlorofluorocarbons" or "CFCs" for short. The chemical formula for R-12 is CCl2F2 (one carbon atom, two chlorine atoms and two fluorine atoms ).

Before Freon: Hot and Muggy With Little or No Cooling

In the era Before Freon (a little over 100 years ago), there was no mechanical refrigeration or air conditioning. If you wanted keep something cold, you had to ice cut from a lake or river during the winter. The ice then had to be stored in straw or sawdust until it was needed during the hot summer months. Food was cooled in an insulated "ice box" that used a large block of ice in the top to absorb heat as it melted (which also meant the block of ice had to be constantly replaced). If you wanted a cold drink, you also had to get a block of ice and bust it up into smaller pieces because there were no ice cubes. This made ice an expensive and not always available luxury for many people.

Some early attempts to develop mechanical refrigeration using compression or evaporation used refrigerants that were not very efficient at carrying heat, or were toxic, corrosive, flammable or all of these. Such refrigerants included ammonia, methyl chloride, methyl bromide, sulfur dioxide, butane, propane and similar chemicals. The discovery of a refrigerant that actually worked really well, was not toxic, corrosive or flammable was a breakthrough game changer. That refrigerant was Freon.

Freon was discovered and developed by a chemist named Thomas Midgley Jr. around 1928 to 1930. Midgley was the same person who in 1921 came up with the idea of adding lead to gasoline to improve its octane rating and knock resistance. "Tetraethyl lead" allowed engines to handle higher compression ratios without knocking for better performance and fuel economy. It was a very effective fuel additive that allowed significant advancements in engine design and output. The only problem was that it contained lead. Like Mercury, lead is a toxic heavy metal that accumulates in the human body. Over time, it can cause a variety of health and developmental problems (especially in children), and even lead poisoning. The millions of vehicles that were burning leaded gasoline were dumping megatons of lead into the environment via the exhaust that exited their tailpipes. In the 1970s, doctors began to notice and document dangerously elevated levels of lead in the blood of school children in most urban areas. This led to further investigations that revealed leaded gasoline was gradually poisoning the entire population! It quickly became obvious that lead would have to go, so leaded gasoline was gradually phased out until production in the U.S. ended in 1985.

The Age of Freon and All the Changes It Brought (Good and Bad)

With the introduction of the "miracle" refrigerant Freon, we entered the Age of Freon. The new refrigerant made it possible to design refrigeration systems that could make artificial ice in any quantity and anywhere in the U.S. any time of year. The new commercial refrigeration systems also made it possible to keep meat and other foods fresh and to prevent them from spoiling as they were transported across the country. Home refrigerators quickly replaced the old cumbersome ice boxes.

It wasn't long until "climate control" systems were developed for regulating the temperature and humidity inside factories to improve production processes, quality, efficiency and profitability. Then came the novel idea of using refrigeration to "air condition", cool and dehumidify indoor spaces for improved human comfort.

The first such uses of indoor air conditioning were movie theaters (1925), public spaces and upscale retail stores. By the 1950s, air conditioning was really taking off with the growth of the post World War Two Baby Boomer generation, suburban sprawl , shopping centers and an exploding automobile population. In the 1960s, around 20 percent of homes had some type of air conditioning (central or window units). By the 1980s, half of U.S. homes had air conditioning. Today, it is hard to find a home in the U.S. that does not have air conditioning.

It was the same story with automobiles. In the 1950s, A/C began to appear in various luxury models as an option. In 1955, only about 10 percent of new cars were factory equipped with A/C. By 1976, it was standard equipment on three out of four cars, and today you probably cannot even buy a new car, truck or SUV that does not have A/C as standard equipment.

What makes all of this a concern is that the world's population keeps growing, and it seems that everybody else in the world wants to live in air conditioned boxes and drive air conditioned vehicles. The world population is now about 7.7 BILLION people, and the world vehicle population is now more than 1.5 BILLION vehicles. If more and more people around the world attain an affluent western lifestyle with air conditioned homes, offices, factories and cars, how will that increase the consumption of fossil fuels and global warming?

Environmental Concerns

Great as air conditioning is, it has two serious environmental concerns. One is that all those air conditioners require energy to drive their compressors and fans. That means more demand on the electrical grid, which in turn means burning more coal, oil or natural gas to increase power generation. Using A/C in a vehicle likewise requires more energy, which it robs from the engine. This, in turn, reduces fuel economy and requires burning more gasoline or diesel fuel. The net result is more fossil fuel consumed and more carbon dumped into the atmosphere that contributes to global warming and climate change.

The other environmental concern with air conditioning is the working fluid inside the system. That wonderful Freon refrigerant that enables the miracle of cooling by absorbing heat from the air doesn't stay sealed inside the system. It invariable leaks out of the system over time. It may take years for most of the refrigerant to escape, but molecule by molecule it will find a way out through microscopic pores in hoses, leaky compressor and plumbing seals, or pinhole leaks in the evaporator or condenser. Or it might escape all at once if a vehicle is involved in an accident that ruptures any part of the A/C system. It can also escape into the atmosphere if it is intentionally vented while replacing a hose or component in an A/C system, or when a vehicle is scrapped.

The same goes for home and commercial A/C units that contain Freon. The refrigerant eventually leaks out or is vented when the equipment is serviced, damaged or scrapped.

Also, because of its nontoxic and nonflammable properties, Freon also made an excellent propellant for all kinds of aerosol spray cans (hair spray, deodorant, paint, etc.). So tons and tons of the stuff was being freely sprayed into the atmosphere every time one of these products was used.

So what is the environmental concern? Because Freon is such a stable molecule, it does not react with much of anything else. There is no natural process to break it down and reabsorb it into other substances.

When Freon escapes from an A/C system and enters the outside environment, it floats around for years and eventually drifts up to the stratosphere. Here, it finally starts to react with other molecules, specifically ozone, which is made of three atoms of oxygen.

Ozone has the unusual ability to absorb ultraviolet (UV) light from the sun. When UV hits a molecule of ozone, it knocks off one of the oxygen atoms. This stops the UV from going any further and prevents most of the more potent UVC and UVB rays from traveling all the way to the earth below. The loose oxygen atom that was knocked loose quickly finds another pair of oxygen atoms and recombines to reform a new O3 ozone molecule. The process repeats over and over zillions of times a day to protect the earth from harmful UV radiation.

When a manmade Freon molecule enters the ozone layer, it royally screws up the ozone reformation process by preventing any free oxygen atoms from recombining with other oxygen atoms to make more ozone. The Freon molecules are also broken down by sunlight, but when the UV knows the Freon molecule apart, the free chlorine atoms combine with any free oxygen atoms that are floating around, preventing the reformation of more ozone.

ozone hole images

NASA satellite images of the ozone hole over the South Pole.

How bad is it? One pound of Freon can prevent the reformation of up to 12,000 pounds of ozone, and it can keep doing this for up to 100 years or more!

To make matters worse, almost every pound of Freon that has ever been manufactured is mostly still with us. Some of it is still sealed inside A/C systems or storage tanks, but the vast majority of it has already escaped into the atmosphere where it has been accumulating and causing a potentially catastrophic thinning of the ozone layer.

In the early 1970s, scientists noticed a significant thinning in the ozone layer over the South Pole that had never occurred before. Additional research showed what was happening and what was responsible: Freon.

Even more alarming was the fact that the size of hole and the thinning of the ozone layer was growing at an alarming rate, increasing in size with each polar season until it covered the entire continent of Antarctica and much of southern part of South America. The hole was forming because of the way air currents swirl and circulate over the poles. A similar thinning was soon detected over the North Pole too. If something wasn't done soon to curtail the use of Freon, the holes in the ozone layer would soon expand over much of North America, Europe and northern Asia.

After much arguing, questioning, disagreement and feet dragging by CFC manufacturers and government officials, it was agreed that the production of CFCs should be phased out -- and quickly to prevent an environmental disaster.

By the late 1970s, the production of CFCs had decreased significantly due to the banning of CFCs as propellants in spray cans. But in the following years, production of CFCs continued and increased as the demand for air conditioning grew. It wasn't until 1989 that CFC production was officially banned in most of the major developed countries, and even then there was to be a gradual phase out over time.

In 1994 and 1995, auto makers began replacing R-12 in automotive A/C systems in new vehicles with a new "ozone safe" refrigerant that contained no chlorine. It was called R-134a, also made by DuPont.

We thought we had solved (or at least slowed) the ozone problem with R-134a, but we soon learned we had yet another atmospheric challenge facing us. Rising levels of CO2 from burning fossil fuels were reaching record levels, causing a measurable and growing increase in average world temperatures. It was called "Global Warming" and it causing noticeable changes in weather : more droughts, more forest fires, more hurricanes and severe storms, more tornadoes in the Midwest, record floods in many places, more forest fires, more unusual weather all around the globe. All of this was occurring because of the added heat energy and moisture in the atmosphere.

R-134a refrigerant

"Climate Change" (a phrase the Trump administration tried to erase from all government documents, websites and reports) was causing havoc around the world. Polar ice caps and glaciers have been melting at an alarming rate, even faster than many scientists predicted a decade ago. If not slowed or stabilized, this will cause ocean levels to rise several feet between now and 2050, flooding many islands and low coastal areas including Florida and much of the East Coast of the U.S.

The R-134a refrigerant that DuPont created to reverse the ozone problem turned out to be an additional contributor to Global Warming and climate change. That's because R-134a has a global warming potential (GWP) of 1200, meaning it retains heat 1200 times more than CO2. By comparison, R-12 was even worse with a GWP rating of 7300.

This led to the development of yet another round of new refrigerants that would hopefully be ozone safe, nontoxic, nonflammable (under most conditions) and have a low global warming potential. The latest and greatest automotive refrigerant is now R-1234yf, a joint venture of DuPont and Honeywell. R-1234yf has a GWP rating of only 4. It also has a relatively short atmospheric life of 12 years, so it won't hang around as long as some of the older refrigerants when it escapes from an A/C system.

R-1234yf refrigerant

Hopefully we got it right this time with R-1234yf. Or maybe we didn't. Time will tell if R-1234yf turns out to have unforeseen side effects and negative consequences.

Auto makers began changing over to R-1234yf in new car A/C systems in 2014 & 2015.

Today, almost all new cars, trucks and SUVs have R-1234yf A/C systems. What's more, the latest generation of A/C systems use better hoses and seals to minimize leakage over time, and contain smaller amounts of refrigerant so less is needed to charge the system. Refrigerant recovery and recycling by professional service facilities has also been required since the change over from R-12 to R-134a, and then again to R-1234yf. In theory this means less refrigerant loss into the atmosphere and reduced demand for new refrigerant. Intentional venting of refrigerant is illegal. But people being people will cut corners and ignore the rules. Recovery and recycling equipment is expensive, and although it is required for servicing automotive A/C systems, many shops still don't have this type of equipment. Salvage yards are also supposed to recover any residual refrigerant from vehicles that are being scrapped. But this seldom happens because the refrigerant has already leaked out or escaped as a result of collision damage. As for backyard mechanics who do their own A/C repairs, it is a joke. There is no recovery or recycling of refrigerant. Any refrigerant that is in the system escapes into the atmosphere when a hose or other component is disconnected and replaced.

After Freon

Today we are in the After Freon era of our environmental saga. Freon and similar CFCs have been mostly phased out of production in the U.S. , Europe and Japan, but they are still being manufactured in places like Russia, China, Mexico and other Third World countries (both legally and illegally). Some of this bootleg Freon has ended up being smuggled into the U.S. for use in older pre-1994 vehicles that had R-12 A/C systems. Following the initial ban on R-12 production in the U.S., R-12 smuggling from Mexico became more popular than drug smuggling as a way of making a quick buck. People also hoarded the stuff hoping to resell it in the future for a profit. Because of these actions, the environmental damage caused by Freon and other CFCs will continue, though hopefully at a reduced pace had large scale CFC production not been curtailed.

The author of After Cooling spent a lot of ink talking about the social inequities that have resulted from air conditioning and how our dependence on keeping ourselves comfortable have changed society while increasing our demand for energy. I agree with many of his observations, although I am not going to write about it here. You will have to read the book to glean the author's insights on these topics.

The final section of the book examines what the future might hold.

Will our ever increasing dependence on technology save us from environmental disaster?

Will we be forced to go back to a less air conditioned way of life? People today are much less tolerant of heat and humidity than previous generations who lacked air conditioning.

Can we find the all the clean energy we need to fuel our expanding appetite for more and more cooling?

Can we change our wasteful energy habits and create a more energy efficient and environmentally friendly way of life, or will we continue with a "business as usual" approach that will likely make things worse sooner rather than later?

Can we find ways to reduce our need for cooling by designing buildings, homes, work spaces and cities to provide better passive cooling (things like more trees, green space, less pavement, etc.)?

And what happens if the changes we have made in refrigerants is too little too late? Will we bring an environmental disaster down on our heads that results in the end of civilization as we know it?

These are challenging questions and challenging times. There are simplistic answers.

Personally, I don't believe the sky is falling just yet, but the climate is changing and at a more rapid pace than anyone thought possible less than a decade ago. Natural climate cycles that have alternated between ice ages and warm periods typically occur at a glacial pace that last for tens of thousands of years with mini cycles in between. But the changes we are experiencing now have come upon us in a geological blink of an eye.

In the early 1800s, the world population was about one billion people. It took mankind thousands of years to reach that level. A hundred years later in the early 1900s, the world population had doubled to two billion. Today we are fast approaching EIGHT BILLION. The problem is we have too many people consuming too many resources on an industrial scale. The earth's resources and environment can't withstand that kind of onslaught.

We may have already passed the tipping point of irreversible climate change. Even so, we need to remain optimistic and continue to look for solutions that will help everyone in the end.

The Shift to Electric Vehicles

The shift to electric vehicles is a step in the right direction. The introduction of new EV models is finally starting to pick up, with several major auto makers saying they will completely phase out internal combustion engines by 2030 to 2035. A growing number of U.S. states as well as European nations have already passed or are proposing legislation that will ban the sale of new vehicles that are not electric.

GM's Ultium electric car battery & chassis

General Motors new Ultium battery platform for their next generation EVs.

New EV battery technologies that require little or no lithium or other rare earth metals promises to reduce costs and environmental impact while improving efficiency, range and charging times. Even so, we are going to have to create a lot of new clean energy to power all of these vehicles.

I predict a combination of wind, solar and nuclear (yes, nuclear) will significantly reduce our consumption of fossil fuels. The potential game changer that may just around the corner is clean fusion power. Scientists have been working on fusion power for decades without success. But recent breakthroughs have shown it is possible and may become a reality within the next decade.

When I was in college back in the early 1970s, the Doom and Gloomers were predicting the world would run out of food or energy (or both) by the late 1980s, or that we would nuke ourselves into oblivion. None of that happened. The development of high yield food crops and improvements in farming techniques outpaced population growth, and the use of fracking, though controversial, yielded more oil and gas then we thought was possible. The Obama administration's push for green energy created wind farms that now provide a significant share of the electricity in a number of states (Iowa 42%, Kansas 41%, Oklahoma 34%, North Dakota 27%, Colorado, Nebraska and New Mexico 19%, Minnesota 18%, and Texas 17% according to current U.S. Energy Administration information). Many coal power plants in the U.S. have either closed or converted to somewhat cleaner natural gas as the price of energy has changed.

windmills in Midwest U.S.

I think the U.S. is on the right path, in spite of the Trump administration's attempts to deny scientific facts while pretending climate change is not real. Sorry, big coal is not making a comeback. The Biden administration hopes to put even more money into expanding green energy as part of its infrastructure package.

My main concern is not so much what we are doing but what the rest of the world isn't doing, namely China, India, Russia and other Third World countries. China is investing a lot in hydroelectric power, also wind, solar and nuclear. But at the same time, they are also building lots of new coal fired power plants. China surpassed the U.S. as the world's leading polluter over a decade ago.

Both China and India have huge populations that are more than five times larger than the U.S. (1.5 billion each versus about 330 million in the U.S.). Both of these countries have growing middle classes that want middle class amenities including air conditioning and cars. Chinese auto makers now sell more cars than the U.S. , Japan and Germany combined (about 25 million cars). More cars equals more CO2 emissions and more fossil fuel consumption. The electric vehicle market in China is growing faster than anyplace else, but how quickly they can make the transition away from internal combustion engines remains to be seen. The air quality in most urban areas of China is among the worst on the planet!

It is hard to predict how all of this will play out in the years ahead. It will take much effort and dedication, but if we can find ways to work together we can mitigate or maybe even solve the challenges we now face with global warming and climate change.

book Related Articles:

Global Warming

The Problem with CO2

Automotive Environmental Issues

The Electric Car Revolution

To More Technical Info Click Here to See More Carley Automotive Technical Articles

Related Links:

Intergovernmental Panel on Climate Change (IPCC) Report (August 2021)

Additional Reading Resources:

Saving Us by Katherine Hayhoe

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