Climate shift question

[Nerys Ghemor]

I have a stupid question. Basically...I'm going with the Pocket Books history of Cardassia Prime, which states some sort of climactic shift occurred 500 years prior to DS9, but it doesn't explain what.

What kind of event could happen to cause a very rapid climactic shift in a planet that would make it get more arid, and significantly diminish the amount of arable farmland WITHOUT making it entirely uninhabitable? Temperature would have already been hot by Earth standards--this does not have to increase. If it does--I don't want to push it TOO far, because we do see Cardassians walking around on their native world in long sleeves and pants without even breaking a sweat. So I'm figuring temperature wasn't the issue, or not a major one.

I'm looking for a disastrous ecological upheaval, but one that can be survived without people having to do the Mad Max thing. (Though if Cardassians are more radiation-resistant, there might be some more wiggle room on that than if we were dealing with humans...but I don't want to stretch suspension of disbelief any further thank I have to.)

I ruled out nuclear war and asteroid strikes because I would've thought that would cool the planet. Volcanic eruption...probably the same thing, though I could be wrong.

One thing I was considering was magnetic field collapse and/or reversal (and if I want to be really mean, have the initial collapse coincide with an increase in solar wind activity), but I'm not entirely sure on the science of that, whether it'll affect the planet's climate or how.

Is there anyone who can point me in the right direction?

 

[Myasishchev]

Well, global warming once killed 90% of all life on Earth, according to some scientists, like Peter Ward.

The original mechanism can be artificial or natural--volcanic eruptions are a good culprit if you're not trying to make a point about contemporary humans, but it's probably more interesting to make the increased carbon dioxide content in the air anthropogenic (or cardassogenic as the case may be).

Methane release from tundra areas can form a positive feedback loop: as it gets warmer, the frozen water in the ground melts, releasing methane, which is a greenhouse gas, making the planet even warmer, so that more tundra melts, releasing more methane, and so on.

The loss of thermohaline ocean currents is also a big worry during periods of climate change. It is apparently a possibility for the Atlantic's Gulf Stream conveyor, and if that current was slowed or halted, it would likely severely disrupt traditional agricultural areas. Same deal for any other planet.

What's much, much worse, though, is that the loss of thermohaline currents signifies the end of the convection currents that bring dissolved oxygen into the deep sea; as the thermohaline currents dissipiate, the chemocline between oxygenated and anoxic water rises. And, of course, under this barrier, no animal life can persist. They are replaced by anaerobic sulfur bacteria, and hydrogen sulfide is released into the atmosphere, destroying the value of beachfront property and increasing the acidity of rain everywhere. I think that as plant and animal life dies, more carbon, previously tied up in biomass, would also released into the atmosphere as CO2 through decay and burnoffs. Oh, and H2S destroys ozone too, permitting a greater concentration of ultraviolet light to reach the planet's surface. The composition of the atmosphere would change over and eventually the sky would turn green, but not that many life forms would be around to see it.

This is what (likely) happened to Earth at the end of the Permian--the worst mass extinction in our planet's history. For what it's worth, I suspect it's what turned Vulcan into such a sucky place (and, given their industrial society, it was probably their fault), although with modern techniques I suppose they've managed to at least clean their air.

Anyway, have you ever noticed that the pictures of Cardassia from space make it look like Venus? Seriously, how is their sky blue? On the outside, it's yellow. It's like a whole planet became Los Angeles.

 

[Nerys Ghemor]

I'm not entirely sure, but I did notice something odd going on with the Cardassian atmosphere.

But on most surface pics (minus that one matte painting after it got blown to hell, which I kind of disregard), I notice a lot of red lighting. I'm not sure whether that's sunset, or perhaps the system primary is redder than Sol...I tend to go with the latter theory in my writing. I also think (though again, not 100% sure on the science) that if you had a lot of haze you could get a reddening effect, correct?

I don't know that I want to go with global warming, though, since at least in my story I won't be focusing so much on how the Cataclysm happened...but more on the ways people reacted to it. I would rather not get my story confused for some sort of comment on global warming.

What other sorts of climate shifts could lead to rapid desertification and agricultural disruptions, without having to go with global warming?

 

[Myasishchev]

A significant electromagnetic burst could do all sorts of nasty things. Nearby or strong enough, it would set the exposed face of the planet on fire; a little farther or weaker, radiation poison every living thing; farther/weaker still, destroy the ozone layer through various chemical processes, resulting in harmful UV exposure, leading to significant die-offs, especially of plant life, resulting desertification, and a temperature rise due to carbon dioxide being released into the atmosphere by, again, decay and burning. Precipitation would remain, but life would be difficult for a while.

You'd want it to be weak enough to not harm all the other planets near Cardassia, though, and maybe have Bajor be in a position to be shielded by its sun...

Gamma ray bursts propagate along the axis of rotation of a star collapsing into a black hole, but I don't know how wide they get. I'd assume far enough to encompass Bajor as well as Cardassia. It's considered unlikely to happen in the Milky Way, as they usually only happen in a low-metallicity stellar population such as we do not have, but I reckon the Galactic Barrier or an anti-time eruption is probably considered pretty unlikely too, so I don't think you have any problems there if you wanted to use a GRB. On the other hand, supernovae happen all the time (relatively speaking) and a plain ol' exploding star would work just fine. Estimates vary on how close one would have to be; taking the low end, a supernova about 50 light years away should significantly deplete an exposed planet's ozone.

If what you're asking for is way to stop it raining, I don't know the answer to that. I don't know how one would remove or significantly disrupt the water cycle in an ecosystem... other than a global freeze. Cardassia Prime's greater heat would generate more storms, not fewer, and more severe ones at that. I always figured Cardassia Prime had a varied climate, like Earth's, just in general about 10C hotter.

 

[Nerys Ghemor]

For an EM burst--could the solar wind do it? And would my idea about a magnetic field collapse and/or reversal serve to worsen it enough to disrupt the climate?

What I've read about magnetic field collapses and reversals suggests those periods can actually last quite a long time.

http://www.theozonehole.com/magnetic.htm

But your idea that something could be out there that KEEPS hitting Cardassia, not allowing the collapsed field to reassert itself, might also be a good one.

As for the arid nature of Cardassia...are you saying that if it doesn't rain as much as Earth, it would have needed to be that way from the beginning? But if we entered conditions like this, I suspect it would be harder for the planetary ecosystem to USE that rain. I can imagine that being a cause for great consternation in some of the areas that didn't turn to desert: rain yet poor crops.

 

[SoM]

How big is Cardassia-Prime's moon? I'm wondering if the planet's axis could have shifted significantly...

 

[Nerys Ghemor]

That, I don't know.

What would cause an axis shift, and what would the effect be?

 

[Timo]

In theory, all star systems might be unstable/chaotic to some degree: certain types of wobble might build up along the millennia and aeons, until there were sudden flips of one sort or another, simply because a star system is a complex multi-body problem. It isn't even a problem of multiple solid bodies, but of rotating bodies of varying viscosity and density - so basically a planet could flip-flop all by itself, after building up enough internal "tension" by the uneven movements of the squishy innards.

It is now taken for granted that Earth's magnetic field is prone to sudden flips, presumably because of the unstable or chaotic movement of the core. This could well happen on the timescale of centuries rather than millions of years. On the other hand, gradual precession of the rotation axis could be entirely nonchaotic/deterministic, take place across tens of thousands of years, and still could result in a climate change that suddenly becomes evident or significant on a timescale of mere centuries.

It's a bloody wonder mankind hasn't yet experienced major climate changes on our own, probably relatively unstable planet. Or then it's just that those have gone by unnoticed, until historical times. Certainly Europe's minor climate changes within the past 500 years have had their effect on world history; something similar, relatively small in scale, could account for the reputed impact on Cardassian history, too.

Timo Saloniemi

 

[Mr. B]

Solar flare? ...some other change in the star's output?

 

[Praetor]

I'd avoid using the moon as the mechanism if only to avoid similarities to the apparent effect of Praxis in TUC.

 

[Nerys Ghemor]

Solar flare? ...some other change in the star's output?

I'm starting to settle on a scenario now...couple a more active solar cycle with a magnetic field collapse and I'm thinking you could really play hell with C-Prime ecologically speaking.

 

[Myasishchev]

Maybe the ancient Bajorans smited/smote them.

 

[Praetor]

^It would certainly be interesting if certain Cardassians felt that way...

 

[Nerys Ghemor]

I'm not sure the Cardassians even knew they existed.

And at least in my own fic...I am not making the connections between the Cardassians and Bajorans as close as certain stories (ahem..."The Glories of the Hebitians") have tried to make it.

 

[Thor Damar]

I'm not sure the Cardassians even knew they existed.

And at least in my own fic...I am not making the connections between the Cardassians and Bajorans as close as certain stories (ahem..."The Glories of the Hebitians") have tried to make it.

Indeed, there is such a thing as going too far. I personally have a problem with the fact that Bajor is far to close to Cardassia Prime (2-3 light years), did it really take them 450 years to reach the Bajor-B'hava'el system?

 

[Nerys Ghemor]

Well, perhaps there could've been brief contacts between Bajor and Cardassia, but maybe for a long time, both parties kind of ignored each other. That is, until Central Command got to the point where they decided they felt like occupying Bajor.

 

[Thor Damar]

Well, perhaps there could've been brief contacts between Bajor and Cardassia, but maybe for a long time, both parties kind of ignored each other. That is, until Central Command got to the point where they decided they felt like occupying Bajor.

I suppose, but for how long? The Cardassians annexed Bajor for it's resources because Cardassia Prime was starved of said resources and it seems that this happened long before the two civilizations first met it other. So how can a predatory empire like the Cardassian Union ignore such a fruitful world for so long?

 

[Nerys Ghemor]

Well, perhaps there could've been brief contacts between Bajor and Cardassia, but maybe for a long time, both parties kind of ignored each other. That is, until Central Command got to the point where they decided they felt like occupying Bajor.

I suppose, but for how long? The Cardassians annexed Bajor for it's resources because Cardassia Prime was starved of said resources and it seems that this happened long before the two civilizations first met it other. So how can a predatory empire like the Cardassian Union ignore such a fruitful world for so long?

What I have wondered is if Bajor used to have more of a space presence than it did: if perhaps they seemed too strong at first.

Another theory I have is that the nature of the Cardassian Union shifted over time. While I do think it was dictatorial right from the start, I think some of the extremes grew over time. I'm curious if you remember Rebek's description in The Thirteenth Order of how the Cardassians and the Xepolites dealt with each other, in a time long before the annexation of Bajor?

 

[Thor Damar]

Well, perhaps there could've been brief contacts between Bajor and Cardassia, but maybe for a long time, both parties kind of ignored each other. That is, until Central Command got to the point where they decided they felt like occupying Bajor.

I suppose, but for how long? The Cardassians annexed Bajor for it's resources because Cardassia Prime was starved of said resources and it seems that this happened long before the two civilizations first met it other. So how can a predatory empire like the Cardassian Union ignore such a fruitful world for so long?

What I have wondered is if Bajor used to have more of a space presence than it did: if perhaps they seemed too strong at first.

Another theory I have is that the nature of the Cardassian Union shifted over time. While I do think it was dictatorial right from the start, I think some of the extremes grew over time. I'm curious if you remember Rebek's description in The Thirteenth Order of how the Cardassians and the Xepolites dealt with each other, in a time long before the annexation of Bajor?

That does kind of gel with my own theories with regards to the founding of and the early years of the Union...

 

[Nerys Ghemor]

Crap...realized I might have to abandon the magnetic field idea I had.

Question: if a species can sense bioelectric fields--as my version of the Cardassians can (though it's a weak sense that requires close proximity), would they also be severely susceptible to a magnetic field collapse?

Or are they two separate enough perceptions that I wouldn't have to worry about potential disorientation due to magnetic field loss being serious enough to mess with their heads to the point where it would wreck their society beyond repair?