Could we counteract global warming if everybody in the world turned on their air conditioners and refrigerators full blast and left the doors open?
Unfortunately, no, for several reasons.
First of all, the world’s supply of air conditioners and refrigerators isn’t anywhere near what you might think by looking around your neighborhood. But even if every citizen of the less-developed nations were privileged to enjoy cool bedrooms and frozen pizzas, the amount of available cold wouldn’t amount to an ice cube on a glacier.
Of course, you expected that answer, but maybe not this one: What you are proposing would actually heat up the world. As you know too well from your electric bills, air-conditioning and refrigeration don’t come free, in either money or energy. Someone has to produce the electricity that they use, and the production process itself gives off a lot of heat; it’s part of the overall energy equation, and therefore part of the environmental problem.
In most cases, the first step in electricity production is to make heat through the burning of coal or by nuclear fission. Then the heat is used to boil water to make high-pressure steam, the steam is used to turn the blades of a turbine and the rotating turbine shaft drives an electricity generator. That is a remarkably inefficient chain of events, and there’s the rub. Or one of the rubs.
Only about one-third of the fuel’s inherent energy ever winds up as usable electricity. The other two-thirds goes up the smokestack as hot gases or down the river as hot cooling water, or else is lost while the electricity is being transmitted through the wires to your house, because power lines are slightly warmed by their resistance to the electricity flow. That’s why birds perch there in cold weather. More than anything else, then, what power plants really do is heat up the countryside. The more electricity you demand for cooling your food and brood, the more heat the power companies must fling into the environment. Instead of thinking about opening the door of your refrigerator, you’d be doing the world a favor by turning the appliance off! Okay, you say, but all of that wasted heat is already part of the global warming picture.
Turning our refrigerators and air conditioners loose upon the outdoors would have an effect over and above that, wouldn’t it?
Again, unfortunately, no.
Consider how a refrigerator or air conditioner does its job.
A refrigerator is really a heating machine.
It takes in warm air, removes heat from it and discharges that heat somewhere else.
The refrigerator removes heat from the air inside the box and throws it out into the kitchen via coils located behind or beneath the box, while the air conditioner takes in air from the room, extracts heat from it and throws it out the window. But—and here’s the main reason your scheme won’t work—these machines throw off even more heat than what they remove from the air.
You might say that refrigerators and air conditioners make more heat than coolth. Here’s why. We know that the natural direction for heat to flow is “downhill” from a higher temperature to a lower one. In order to reverse that natural tendency and force heat to go “uphill” from a cool interior to a warmer exterior, the fridge or AC has to use electrical energy. (That’s why you have to plug it in.)
And that electrical energy, after it’s done its job, turns into heat. You can feel it by touching the outside of the refrigerator or air conditioner; it’s warm. When you add it all up, then, there is more heat—usually about one-third more—coming out of the “cooling” machine than the amount it removed from the box or the room. The bottom line on the energy balance sheet tells us that these machines are actually heating devices.
The final nail in your cool-the-world coffin is this: Even if fridges and ACs could operate without using any electric power, the best you could hope for would be to break even: one calorie of heat discharged somewhere for every calorie removed from somewhere else.
And that wouldn’t change the world’s overall quota of heat.
All you’d be doing is moving it around.