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There are limits as to how much some of this stuff can be simplified Isaac Send a noteboard - 22/11/2010 04:27:10 AM
In that case the issue of a given side being exposed to the sun for a given time far longer than the other seems no issue at all: Temps are the same on both sides, so whether a planet with a very hot/cold side retains more heat than one where the two frequently switch orientations is moot.


Your mistaking an aspect here, Venus's slow rotation is in all probability the cause for it's circumstances, not an irrelevant side factor, as is it's immense atmosphere. The surface temperature of venus is effectivelly isothermal, all well and good, dig 20 feet into the ground on most parts of Earth and you'll find it 58 deg Fahrenheit, regardless of time of year or day, effectively Isothermal, pretty much all celestial object in orbit around a star receiving most of their juice from that star have a given depth they become Isothermal or nearly so. In terms of mere day time flux, typically on Earth you only need to dig a foot or two down to get to a depth where temperature varies only with time of year and not with day. Venus has weather, it just doesn't have any variance of tmep at the surface, the atmosphere is massively thick.

A LOT of this seems irrelevant if there's no significant difference between the un/lit sides of Venus; I'm beginning to wonder why you even mentioned the longer days if the greater pressure means they have even less effect on temperature variations than our own 24 hour days.


Temperature on the surface, don't get to "Earthbound" in your thinking. You are trying to use Venus as an example of greenhouse effect analogous to Earth, to understand why it is not you have to understand the massive differences between them. Forget about Venus current status, it has virtually no axial tipping, it has a daytime that hast two months and receives twice the light, more than a hundred times as much energy hits it during a day. It's circumstances are viewed as a result of these factors, not disconnected.

I've bent a few pieces of wire in my day, and I know what happens; I can't recall ever spinning in circles while doing so, so I can't be sure that wouldn't make a difference, but if there is one that analogy fails to demonstrate it. Likewise, convections effects on heat transfer within the planet are irrelevant if pressure is already maintaining an essentially constant temperature across the globe. Regarding the example, is it really accurate to treat the cold and hot sides of a globe as if they were two separate bodies? I'm not convinced albedo is a sidetrack at all, but since heat radiated from planets is almost entirely heat they first absorbed (minus things like the heat of gravity compressing its mass) I was thinking a lot about it and reflected heat from the start.


When they're that large and in regards to blackbody radiation? Yes, but the example was merely for ease of mental absorption. Blackbody radiation is strictly a matter of temperature, were we to redo those instead with only two globes, one of constant temp and one that was +/- the same tmep from that we'd have gotten the same values, cut in half in terms of output from the lower total surface area but same in ratio.

Maybe it's just because I'm the Tangent King, but saying your analysis "doesn't even include the effect" a magnetic field and rotation have on weather seems more like an allusion to an allusion than actually covering it. I'm not asking for a geo or astrophysics primer here, but you're not giving me much reason to consider the magnetic fields effect on Earths heat loss beyond the friction between it and the solar wind or a flare.


The total effect of magnetic fields on weather are not known, evidence a this time is inconclusive as to weather magnetic pole switches or movement cause climate change, though last I checked it was felt that it probably did not significantly. But that was in regards change pole location. As stated, it keeps various particles out, those particles not only would bring in heat but also would tend to have chemical effects when they struck, a parallel being the effect of sunlight on oxygen/ozone.

Yeah, I know the law, just hadn't stopped to think that Venus really is that much closer to the sun; my bad there. Whether or not I'm understanding the preceding properly, that alone should make an apple to apples comparison impossible. Of course, since water boils a long time before lead melts, it doesn't let us off the hook either. ;)


I believe it has been shown that a 100% CO2 atmosphere on Earth would not cause water to boil, but I can't recall where I saw that to link an analysis, regardless, keep in mind that a rise in CO2 will not cause it to become 100% Co2. The Earth's Atmosphere weighs about 5 Billion Megatons. Last I checked world annual CO2 output is around 30,000 megatons, we do leak some air into the void but as pressure rises boiling point of water does too, and of course it take a lot more energy to boil water than it does to get it up there from ice. Not that 90C water would be particularly fun either.

I'm not saying we're identical though, just that Venus provides us an excellent example of how a runaway greenhouse effect really can have dire consequences, despite the claims of those who insist it doesn't matter even if it IS happening here. Too much of that, hell, too much of US policy in general these days, strike me as a rationalized excuse to do nothing, with the incidental effect that those who materially benefit from doing nothing continue doing so. And accuse reputable scientists of bias and greed.


The difficulty here is that where 'carbon' is concerned these days people's scientific opinion seems governed by their politics, more than the other way around, and neither is strictly appropriate but the latter is a bit more acceptable. You assuming something 'must be done' but the flip side of the coin is that there are a lot of us who think that 'something' should be figuring out what is being done, and then figuring out the the actual problem that needs a solution. I frankly consider the long-range threat minimal, because it seems to have some fairly nice silver linings and the actual thunderbolt seems addressable, and I really am not convinced any truly extreme effect will occur.

Your take on the Climategate issue I will have to bypass, I do not believe the accused were innocent or slandered. Nor do I now wish to hear the moans from those who for years have slandered every skeptic on the various Green fads as fools, religious fanatics, or greedy corporate hacks. After decades of that crap over nuclear matters we are only now get a few vague half-ass apologies for all the shit we took for years of telling people to relax.

Sure, but skepticism doesn't equal inaction, in fact, it actually means you hedge your bets, which is what taking steps to reduce our undeniably and dramatically increased CO2 emissions in the last two centuries would be. Setting that aside for the moment, however, I can think of several HUGE downsides to ignoring accurate predictions of significant warming:


Skepticism means proceeding in the most rationale fashion base don available evidence. In my opinion there is no need to 'hedge our bets', fossils fuels are limited resource and unable to indefinitely meet our growing energy concerns alone, that is sufficient reason for me to support research and development of more efficient devices and alternate energy sources, I of course need no reason to support the former, efficiency is always good, and industry tends to strive for it rather enthusiastically.

You are right that 'hedging ones bets' is wise, but only in total context, were we to adopt all the policies the greens want, we'd lay more misery down on the world then both World Wars combined.

First and foremost, I can walk from the Prime Meridian to the International Dateline a lot faster in Antartica than I can in Guatemala: The amount of tundra we'll reclaim is dwarfed by the amount of equatorial land that would become uninhabitable desert.


I advise you too look up how much tundra there is, and remember that Antartica is actually a whole continent. Second, why would those places become desert? Hotter temps mean more rain, it will doubtless not be evenly spread, but on average it should be, and these effects would not happen overnight, we are talking decades, further, you seem to ignore that we have become very advanced at techniques to protect areas from becoming desert, we've made massive advances in arid agriculture as well and even developed some nifty ways to turns coastal deserts into high producing land, renewable passive solar desalinization and agriculture facilities. We will doubtless continue to improve those techniques. But again, do a logic check, the total rainfall will increase if temperature rises, there is no particular reason to assume places will get less rainfall, most places will get more, if weather patterns begin to shift, well they do do that from time to time, it is not particularly labor intensive to adjust ecology over a few decades to match the new local norm. In terms of deserts, well, frankly polycarbonate is not that expensive, as greenhouses they tend to represent a better long-term capital investment then switching to, say, solar panels, and for that matter more volatile weather would probably make windmills more cost effective. Green-tinted polycarbonate runs about $50,000 an acre for the material itself, and would reflect green light, useless to plants, right back up into the atmosphere in desert regions, and they have no meaningful water loss which can be resupplied with saltwater anyway instead of fresh water. Greenhouses produce far more calories per square foot than any other method anyway. It's entirely possible agriculture will switch entirely away from open air just because there are a lot of emerging economic advantages to having your whole 'field' contained inside a place where irrigation is unnecessary, there is no soil erosion and loss, and you can pump tons of CO2 into it. I think you'd feel a lot better about this whole thing if you spent some time researching greenhouses and emerging aquaponics technology.

In addition, not only do very few people live on that tundra now, but a LOT of people live in those equatorial regions. I don't think you'll be able to sell Brazil on global warming by telling them all to move to Canada (for that matter, it might make Canada a hard sell, too. ;)) That brings us to another problem: A disproportionate amount of the worlds population lives near the coast, and even more of it lives near SOME source of water, fresh or salt, and the best part is it's often the most impoverished and therefore least capable of adapting to drastic climate change. If the oceans rise and the Himalayas flood the Ganges India is in a very bad way, and the solution is not to move into the Himalayas; lukewarm barren rock is still barren rock. Until/unless equatorial temperatures reached the point where rainfall was rare, the monsoon rains resulting from the melting glaciers would be brutal as well. For coastal populations (which is a LOT of people) any sea level rise is dangerous, because water always finds its level: A sea level rise of just a few inches could permanently drive the shoreline 50 miles inland. The question isn't how much of FL is above sea level now, but how FAR, and for most of it the answer is "not very".


Covered some of that above, but one points out that when land sink below sea level it does not actually become 'sea', dikes can be constructed. Those areas get hit so hard not simply because their weather suck but because they are simply under-developed and horribly ruled. And Coastal populations shift all the time, the shoreline is not and never has been static, houses are typically only built to last 20-50 years before maintenance cost exceeds construction cost. Cities are not even fixed locations, they tend to migrate, and we already know how to preserve shoreline when necessary.

Then there's the ice caps. I try not to think about the ice caps, because they act like a natural thermostat, absorbing a great deal of heat when they melt, then accumulating frozen precipitation when temperatures drop. You know the drill: Until the ice melts it can't get above 0 centigrade, and it takes almost as much heat to accomplish that state change with NO temperature increase as it does to boil the water once it's melted. So long as there's snow on the ground here even the ambient temperature won't get more than a degree or two above freezing, and the ground will remain frozen throughout that time. Once the last of it's gone though there's nothing to absorb that heat in a state change: More energy means higher temperatures, period. Well, until we reach the point where all the water turns to steam, but one way or the other that won't be a problem for humans....


I am aware of the basic thermodynamics of water Joel :P While I personally dislike the heat, plants don't. I don't really care what happens to people's living space so long as the net amount of arable land does not diminish, we (developed countries) only use about 2% of the pop to grow food, our big-ass cities can easily be diked or moved. We don't build buildings to last for centuries, but for decades. If you look at population density charts moving over decade span the whole of humanity ebbs and wanders around the map like crazy.

It really doesn't matter though. Whatever part of the current socio-economic system we look at that those running it have little incentive and thus little desire to change anything, so they'll continue to find reasons why they not only can but MUST do nothing. It doesn't matter that less waste and clean renewable energy are in everyones best interest, because cheap power is anathema to those who sell it for a living (cheap labor, OTOH.... ;)) That's why consumers will insist on poisoning, choking and roasting themselves BECAUSE IT COSTS THEM LESS. Once again, that's why businessmen whose only bottom line IS the bottom line accuse academics of greedy bias. It's like Lindsay Lohan ignoring her drug treatment counselor on the grounds that addicts can't be trusted. :rolleyes:


That's the politics overriding the reason. You view 'the powers that be' as an enemy with selfish motives and ill-intent, I do not. I have noticed that that tends to be the driving force in most people's views on the matter. I consider a robust, industrialized economy as better equipped to handles this problem or any others which may pop up, and most of the solutions proposed by the greens that are not already things industry required little encouragement to adopt as threats to that. I think most greens view us as ripping down our house to keep the fire going so we don't freeze to death while ignoring the gaping whole we're putting in the walls and roof, from my perspective, adopting things which damage the economy is the same thing. Some people wish to meet this 'crisis' with a singular solution they feel addresses all the problems of society that they see, typically massive economic redistribution and a lot of times some return to an idolized past. Reasonable, sane measures are better, I tend to think our 'greedy leaders' are actually pretty good about doing this, whereas I tend to feel most of the enviro-types are bound and determined to take us down a road paved with little carbon friendly bricks scribed with the words 'good intentions'

Love of money is the root of all evil, and if I pinned my hopes on Earth or any place visible from it I'd be very depressed. As it is I'm just debating how ethical reproduction is in a world where each generation is going to be increasingly screwed AND under increasing pressure to reject salvation.


Yeah, see above. :P
The intuitive mind is a sacred gift and the rational mind is a faithful servant. We have created a society that honors the servant and has forgotten the gift.
- Albert Einstein

King of Cairhien 20-7-2
Chancellor of the Landsraad, Archduke of Is'Mod
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So, I think I found a way to actually prove if Global Warming is happening. - 19/11/2010 01:22:49 AM 655 Views
The idea that CO2 in the atmosphere holds in heat is not in dispute - 19/11/2010 02:13:02 AM 523 Views
One need look no further than Venus. - 19/11/2010 03:22:50 PM 466 Views
To find a ludicrous parallel? - 19/11/2010 04:38:12 PM 418 Views
Not THAT ludicrous, just more extreme. - 19/11/2010 05:29:23 PM 449 Views
Re: Not THAT ludicrous, just more extreme. (edit) - 19/11/2010 07:25:21 PM 402 Views
Re: Not THAT ludicrous, just more extreme. (edit) - 22/11/2010 01:47:15 AM 1068 Views
There are limits as to how much some of this stuff can be simplified - 22/11/2010 04:27:10 AM 609 Views
With apologies for the delay. - 03/12/2010 03:54:26 AM 582 Views
I hate computers sometimes - 03/12/2010 05:10:36 PM 513 Views
Re: - 19/11/2010 02:41:29 AM 510 Views
Entirely agree - 19/11/2010 08:42:51 AM 392 Views
Wouldn't prove anything - and your experiment is very flawed - 19/11/2010 10:57:41 AM 423 Views

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