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ukoku
2009-May-21, 06:06 PM
I have a few questions related to the greenhouse effects on our nearby friends Mars and Venus. I sent this message to Phil, but since it's not quite his area of expertese, he recommened that I bother you all with it. Hopefully it'll tax your imaginations, or at least give you a couple chuckles.

(Even though it does involve planatary science, I thought this section was the most appropriate.)

I am currently writing a novel in a fantasy setting, and recently have started mapping out the planet. Iíve discovered that I am too left-brained to have a scientifically inaccurate map, so Iíve attempted to incorporate plate tectonics and such into its design. The main continent is roughly the height of the North and South Americas, smoothed together and filled out a bit.

However, Iíve run into some problems because though the planet is Earth-like, a plot-factor directly effects the environment. Due to a magic spell, the main continent has an unchanging ďSummerĒ climate. The coldest and dampest areas never go under 60 degrees F, but along the equatorial line is a desert that spans the continent, constantly well above 100. The continent has been under the spell for between 3000 and 5000 years.

Of course, being fantasy and magic and all, I could just say ďItís Magic!Ē and isolate the weather without explanation. But I canít help but wonder, so I began to ponder the effect the continentís unnatural climate would have on the rest of the planet.

First I would assume that the constantly rising air would be frequently pulling in winds from all sides over the ocean, keeping the continent wet. But due to the high temperature, would the water evaporate too quickly, causing an arid landscape?

And how would this affect the continents on the other side of the world? Would they be very dry if the main continent is taking the water? Would they be very cold, or be picking up the heat from the main continent? Would they be extremely windy, possibly with extreme weather as a result? I donít know enough about planet climate to answer these questions.

My biggest question, however, deals with the rapid Greenhouse effect on Venus, and Marsís potentially easily-changed climate. From what I understand, ancient Venus once had water-filled oceans like Earth, but experienced a rapid greenhouse effect which evaporated it all. (Either due to high carbon content in the air, or by closeness to the sun, or a number of other theories.)

I have also read theories that Marsís environment could be warmed with relative ease, were something to happen to slightly melt the Carbon Dioxide-filled polar caps, because the released CO2 would cause a greenhouse effect.

My big question is this: if an entire continent is kept at an unnaturally high temperature, and is unable to cool itself properly for a long period of time, would this cause a greenhouse effect to occur? How quickly do you think issues would begin to arise Ė in 3000 years, would the planet be beginning to overheat, or would it already be well underway? Would it be plausible to say, given enough time, the planet would experience something akin to Venusís past, and leave the planet waterless and lifeless?

PraedSt
2009-May-21, 10:12 PM
Well this is difficult! I presume it'll be very windy. And by Earth-like you mean the works? Orbital distance, seasons, continental cover, atmospheric compositions, etc?
And I have no answer to your Greenhouse question...

Magic it away! Why not?

p.s. Welcome to BAUT.

Van Rijn
2009-May-22, 05:40 AM
My big question is this: if an entire continent is kept at an unnaturally high temperature, and is unable to cool itself properly for a long period of time, would this cause a greenhouse effect to occur? How quickly do you think issues would begin to arise Ė in 3000 years, would the planet be beginning to overheat, or would it already be well underway? Would it be plausible to say, given enough time, the planet would experience something akin to Venusís past, and leave the planet waterless and lifeless?

I think the first step in answering your questions would be to look a little more into the specifics of what this magic spell is supposed to do. You've stipulated that it keeps the continent at an unnaturally high temperature, but how? Is it adding more energy to the planet, concentrated over that continent? Is it acting as an artificial greenhouse effect but just over that area? Is it somehow removing energy from the rest of the planet and concentrating in that region?

Tog
2009-May-22, 10:19 AM
Maybe the magic creates a double bubble over the continent with a vacuum between the two sells; effectively, a thermos bottle. As heat rises in the bubble, the hot air is expelled to the desert and cooler air is brought in from the pole.

Ara Pacis
2009-May-22, 10:49 AM
I think it depends on how large the continent is compared to the planet's surface and the size of the other continents. It may not have much of an effect on he planet as a whole as the intervening oceans might moderate any issues with the continent of magic.

darkhunter
2009-May-22, 12:19 PM
In my Fantasy Role Playing home-brew world, I have a similar desert--and it's balanced with a region of unatural cold. The cold region is glacier covered and is protecting the land of the "Robed People"--the desert is a side effect because they needed somewhere to dump al the heat.

How does magic work in your world? Does everything have to balance out?