The backyard dynamo analogy
Imagine an electric dynamo or generator, running flat out in the sun all day, in your backyard. You can have it driven by anything, it doesn't matter. That is the earth.
The IPCC, Al Gore and company, would have us believe that the temperature of the (very thin) metal casing of our dynamo is increasing because it has been repainted and someone has minutely changed the amount of one of the trace ingredients in the paint. That's the atmospheric carbon dioxide. That increase has not affected the colour, just the heat-insulating capacity of the paint. Fair enough, but …..
The fact that the dynamo is running flat out and is as hot as hell down at the contact between the rotor and the stator, is of no consequence to the IPCC and its anthropogenic greenhouse model of climate change. It is regarded as trivial. Uh-huh?
The earth's mantle and core rotate at a different rate - that is why the planet acts as a dynamo. If you think "hot as hell" is an exaggeration, down at the core-mantle boundary, the laws of physics say the temperature is about 5,000 degrees centigrade. That is almost the same as the surface of the sun. The sun's atmosphere gets to millions of degrees C, but at the surface itself is curiously just 6,000 degrees C. So, it depends how hot you think hell is, too hot and souls would melt, never mind what insulation the devil tried.
The heat generated deep down in the earth has leaked out to the surface and beyond since the core and mantle differentiated, maybe about 5 or 6 billion years ago. This is all forgotten by both happy and climate-bothered hominids. Dynamos do not run cold.
If you think the crust is perhaps too thick to be affected by this internal heat, consider this: If our dynamo is the size of a soccer ball, the crust is just the thickness of a very thin pencil point. Not even as thick as a single coat of very thin paint. As you go down deep mines, it gets a lot hotter. I know that first hand - a mile-an- - half vertically down in the Doornfontein gold mine, working there as a student, I was as wet from sweat in about three minutes as if I had stood under a shower. And the heat gradient near
Old dynamos pole, that is, they wear and at various places, where the rotor and stator rub on each other more than at others. Those points of friction generate most heat, not surprisingly.
It is not that the earth is wearing out, but its rotation is complex, so the contact region between the core and the mantle is not a perfect sphere. Also, over time, the bumps down there move. Plumes of material rise above them, in the mantle, and show up at the surface as temperature and magnetic hot spots. Volcanoes erupt, plates crack, and smokers are found on the sea floor. We are fussed about a temperature rise of about 0.8 degrees centigrade in a hundred years. Basalt melts at about 1,100 degrees centigrade, and molten basalt is what most volcanic lava is. So a shift of 0,8 degrees at the surface is not particularly awe-inspiring. The hundred-year temperature rise, as you probably know, was entirely wiped out in the past year, much to the consternation of the AGW folk. Their model cannot cope. But pluming on the sun is down, that is, sunspots are at their lowest for a very long time. So maybe pluming deep down in the earth is down a bit too, for the same reasons, whatever they are. Perhaps orbital irregularities involving all the planets affect pluming and the magnetic fields of the sun and all the partially liquid planets, such as ours. Just a guess.
The sun is also a dynamo, and of course puts out vast amounts of heat. The magnetic fields that the two generate interact, and when the earth's magnetic field weakens, as it is doing now, its magnetic shield weakens and more solar heat gets down to the surface here.
In the last hundred years, the very hottest surface hotspots have been on and around the
The paint is irrelevant. I rest my brush.