Let’s assume that it’s possible to get very cheap electricity via nuclear fusion power plants, and that these plants can be produced cheaply enough that any country can afford to build as many as needed. What benefits and problems would result?
Hydrogen-powered vehicles would be feasible. Unlimited clean water could be made via distillation plants. But what problems would result?
Global warming, after all. Any use of energy creates waste heat. Make free energy available, and everyone will use lots of energy. If everyone in every warm climate in the world could afford air conditioning and tons of refrigeration, the amount of waste heat being pumped out of the conditioners and fridges would be phenomenal. Ditto your desalination plants. Even lighting produces waste heat, sooner or later. See Ringworld for a discussion of why the Pierson’s Puppeteers had to move their homeworld further away from its sun.
Ah… no. The waste heat from the fridges and AC units is just being moved from one place to another. It’s not creating heat. Global warming is caused by the refrigerants in the AC units that get up in the atmosphere.
But free energy would allow us to burn through other resources that much faster.
Science fiction books really aren’t a good reference. I would also think any civilization with the technology to move their planet could find a less extreme way to cool it.
No, the point is that cooling systems move unwanted heat around, and add in some waste heat of their own. So everyone who wants an aircon unit gets one, and all the nasty heat that was in their living space gets pumped out of the vent. Plus interest. The interest is the killer. The free energy ensures that there will be a lot of interest-bearing energy transactions. Add to this the waste heat from other energy uses not related to cooling. Every use of energy creates some.
Whether or not there are any refrigerant chemicals getting into the atmosphere is a side issue, and for that matter, refrigerant chemicals and similar nasties aren’t implicated in global warming but in the degradation of the ozone layer and consequent increase in ultraviolet radiation. So before you pick apart my science, take a look at that beam in your own eye, friend.
Other ways to cool a planet? Yes, a nice big solar shield in orbit would be the way I’d go.
The global warming we’re seeing now is a result of CO[sub]2[/sub] produced by the burning of fossil fuels. If we replace all fossil fuels with fusion reactors, I’d imagine the global warming would be significantly reduced, even if you take into account the excess heat produced.
True as far as that goes, but the question concerned free electricity, and you have to postulate a massive upsurge in use. Which isn’t to say we shouldn’t make a beeline for controlled fusion, if only the technical problems actually can be cracked, I mean, we’ve been making hopeful noises about it since the 1950s.
Except that the cause of global waming is not excess creation of heat, but the inability of the earth to radiate that excess heat into space. “Free” electricity as postulated would decrease global warming as it would eliminate almost all manmade sources of gasses that keep excess heat in the atmosphere. The sun provides more heat to the earth in a day than we could possibly release into the air using AC units. (Checks to make sure this is not GQ, lazily does not go do the calcs).
And once again, true as far as that goes. However, at present we do not inhabit a world in which everyone uses as much energy as the average US citizen, not by an order or two of magnitude. How do we look if everyone can, thanks to a number of big-ass fusion reactors? The sun is still providing lots of heat to the Earth, and all the terawattage of those fusion reactors gets added on top. All of it. Even that which does useful work ends up as heat eventually. The only exception is that portion of energy which radiates into space as visible light, and even some of that gets absorbed in the atmosphere. Meanwhile, presumably the Earth’s ability to radiate heat does not increase.
(also lazily does not do the calcs)
Well, actually, if we stop dumping CO2 into the air, the ability of the earth to radiate heat will increase, though only very slowly. But BoringDad is right. The waste energy as heat we produce is utterly insignificant (by more than one or two orders of magnitude) to the global climate. Really, truly, completely insignificant. Global warming is all about tipping the balance between the immense amount of energy added to the system by solar radiation and the rate at which the earth radiates that energy back into space.
Yes, I know perfectly well how global warming works. I just did not feel like going into a long explanation about CFCs, ozone, CO2 in the atmosphere and whatnot. The point being is that the heat generated by all that machinery on earth is an insignificant contributor to global warning.
Excellent!
Smithers: Well, Sir, you’ve certainly vanquished all your enemies: the elementary school, the local tavern, the old age home. You must be very proud.
Burns: No, not while my greatest nemesis still provides our customers with free light, heat and energy. I call this enemy… the sun. Since the beginning of time man has yearned to destroy the sun. I will do the next best thing: block it out!
*
I can see where the misunderstanding arose though, since you originally said that AC units were just moving heat around, not generating it; this simply isn’t a true statement, or they would be perfect, entropy-less machines. It may be that the heat added is insignificant, but that isn’t the same as what you said.
Even though it has been addresses, I must reply.
This has nothing to do with global warming, nada, zilch, and the like. The Globlal Warming Unproved theory (or GWUT) has to do with man made greenhouse gases trapping the heat of the sun. Nuke power bypasses this ‘theory’, and is basically ‘free power’ as far as this unprved theory is concerned.
Also A/C units have nothng to do w/ the unproven ‘global warming theory’, but it has to do w/ the distruction of the ozone theory. they are unrelated to each other, except for the absolute fact that the white man is 200% to blame.
Let’s be fair here. Global Warming due to greenhouse gasses is fairly well accepted by science. It would typically not be classed as a crackpot theory such that it needs to be specified as unproven. The properties of various gasses and their behavior in the atmosphere to reduce radiation and retain more heat are fairly well established. It’s simple engineering.
If you want to note that you disagree with assigning such behavior to Man’s influence on the environment, that’s another story. Certainly reasonable agument as to whether current CO2 levels are solely due to man, a typical historical swing, etc. Of course, even if it is a typical historical swing it seems like we should make whatever attempt we can to slow it down. I am not really in favor of another mass extinction due to a normal and typical massive climate change.