Then there is the personal dimension for grudging change to AC. Following a string of 90 degree days - unusual for our area, but not for a global warming world - our evaporative cooler finally conked out. The cost of repair, we learned, would be nearly as much as just buying a new one. But hey! The service person alerted us, if we got central air conditioning instead it would mean more even cooling throughout the house plus less expensive upkeep. Also, how can you turn down a 15 year warranty?
And so we bit - and I must add - we haven't regretted it given we now can breathe without the constant allergy attacks from pollens blowing in, not to mention the smoky air from fires in the Pacific Northwest, and the occasional skunk odors (After the varmints let loose on a dog or cat outside and the noxious fumes found their way inside - through the swamp cooler vents.)
However, two days after installation we learned we'd become "eco-criminals" by way of our purchase, since this was one of the worst things for planet Earth. According to the Mother Jones article, 'Chilling Effect' (Sept. -Oct., p. 86), AC is damned near wrecking what's left of the planet. (But then, you have to understand, as temperatures now hit all time highs - in locations from Delhi to Budapest, normal humans are eager for some kind of relief. And the heat won't abate as we move inexorably closer to the runaway greenhouse effect.)
But the nation with the most air conditioning units isn't China or India but the United States, as 'Muricans have moved to hothouse locales like Miami and Phoenix - as well as other Sun Belt communities - making it a literal necessity. Here in the mountain West, in the years before about 2000, few had AC and the 90 degree days each summer usually didn't exceed 7 or 8. Now they exceed 20 and often more, as the climate warms. (The temp. forecast in Denver for today's Ravens-Broncos game is 91 F). Any idiot who's lived here for decades can detect the change and it's not merely anecdotal or "subjective". Nor is it a result of "normal climate cycles".
So AC is now a built in convenience in hotels and homes. And all told Americans spend an average of $11 billion on cooling each year, releasing some 100 million tons (0.1 gT) of CO2 in the process - or the equivalent from 19 million automobiles.
The pollution effect is one thing, but as the article points out, as more and more heat sufferers install AC there will be more strain on electrical grids (important here in the U.S. where the power grids are antiquated and in need of repair - updating) as well as more CO2 is pumped out.
One 2009 study - whose results I would not dispute- predicts that by 2100 demand for heating will decrease 34 percent and demand for cooling will have grown by 72 percent. But given what we already know about global warming has been underestimated, I'd warrant the figures will actually be 0 percent and 100 percent, respectively, by that date.
Of course, as the MJ article points out, more efficient equipment might mitigate some of the effects, but alas the overall, absolute increase in AC units worldwide will more than wipe that benefit out.
There are, however, things those of us with ac can do to mitigate our own impacts, including ensuring our homes are well insulated.(Seepage accounts for 30 percent of the system's energy consumption so that insulation can also reduce electrical bills.) Setting the thermostat at 78 F instead of 72 F also confers benefits, lowering the CO2 dump as well as saving on average $100 a month.
The article notes that swamp coolers (which we used to have ) are more efficient in dry climates than air conditioners - which is true. BUT, left unsaid is how the incessant moisture wreaks havoc in the home, increasing dampness in carpets and wood, as well as encouraging mold. The swamp cooler we had also had to be open (e.g. exposing a veritable hole in one wall) whereupon centipedes, wasps and other unsavory critters could gain entry. And, of course, on account of the design of the cooler - being open to the outside- one still had to deal with smoky air, as well as skunks. The ac solves all those problems, though yeah, there is a sacrifice in efficiency.
In the meantime, we will do what we can to be good stewards and dedicated enviros-turning off the AC completely as soon as the temperatures outside get a bit cooler!