Saturday, February 26, 2005

Global Warming or is it?

Paul@Wizbang on News by Press Release.

Welcome Wizbang! readers.

I know there have been a lot of posts, scientific studies and such, but I wonder if anyone has pondered that perhaps its just one giant heat transfer problem.

In modeling the earth as a heat transfer system, one must look at three different parts, the conduction (and somewhat of convection) from inside the earth to the surface. From the center to the outer crust, its a convection problem, making the assumption that there is nothing but magma in the center, and since magma can flow and change course, we have to assume convection heat transfer properties. From the inner surface of the earth's crust to the outer surface of the crust, its heat transfer, even though its a very small amount.

Earth's composition data
*Picture taken from The Interior of the Earth

I'm not going to go too much into detail about the conductivities of the various materials, but suffice it to say that there WILL be heat transfer. There always is. Its the "Zeroth" law of thermodyamics, If there are two objects in contact, one at a Higher temperature than the other, then (in layman's terms) heat will always flow from the higher temperature object to the lower temperature object until their temperatures are equal.

Ok to start off this problem, that-which-was-our-solar-system was fleeing the big bang (probably didn't want a repeat incident) and spinning at an uber-fast rate. At some point, the earth was flung off of that huge ball of matter and continued its orbit around the sun at a super high speed. To make our problem simple, let us assume that it was all a constant temperature (the temperature of the huge ball of fire that which was our sun). That's pretty freakin' hot! How can you complain about global warming when the earth was super hot to begin with?

Anyways, as I mentioned above, there are three modes of heat transfer, radiation, conduction, and convection. Conduction is the heat transfer of two solid objects in contact. Convection is the heat transfer when dealing with a fluid flow, its basically conduction, but with moving particles, and thus has to be modeled differently. Radiation is a whole other ball game. Heat transfer by radiation has to do with the the difference of energy states of two objects. Radiation is the only mode of heat transfer that can occure through a vaccuum, if it weren't for radiation, we wouldn't have the life here on earth.

Back to the problem, as heat was given off by the earth through radiation to other particles out in space somewhere, the outside temperature of the earth cooled and formed a "crust" layer. This crust layer slowed down the rate of heat transfer because its temperature is closer to the temperature of the "outside surroundings" out in space and since heat transfer is related to the temperature difference (actually radiation is the temperature to the fourth difference-- Tsurf^4 - Tsurr^4), the heat transfer lessened.

Now the heat transfer from inside out is increasing because the temperature difference between the core of the earth to the crust is increasing, so the heat starts flowing even more to the outside, as that heat starts to flow more, then the surface temperature heats up as the crust matter stores more energy. When the temperature on the outside surface of the earth heats up again, then it gives off more energy to the surroundings in outer space, cooling the surface of the earth again, continuing the cycle.

Considering that our planet is probably a quite young planet as the universe goes, the earth will eventually find an equilibrium state, but Notice that the surface temperature of the earth went from VERY hot to VERY cold (read, ice age!!!), back to mediocre warm, to mediocre cold, and as it continues to "hunt" to find the steady state condition, the surface temperature of the earth, and by convection, the atmospheric temperature, will continue to vary up and down a little.

Of course, the sunspots and radiation from the sun throws a few curveballs, but the basic premise holds true.

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