Ozone hole may disappear by 2050

[alanschu]

Where does the matter go when it "sheds?" Does it turn into gas? I can't imagine it escaping, which would mean the atmosphere gets filled with even more junk.

 

As for the proof, the Soviets landed a probe there so I imagine it looked around and went, "Oh look, Volcanoes."

[Fenghuang]

Yeah, it does escape. Hella pressure dude.

 

Also there's evidence of a similar event occuring on Earth in the distant past, but instead of crust, it was saltwater pockets sitting on top of volcanoes boiling over and popping. Supposed to be where the flood legends found in most cultures come from.

[alanschu]

If it escapes, it must have quite the escape velocity, unless maybe it somehow breaks down molecularly.

 

I'm not disputing that it somehow becomes gaseous, but rather what happens to it when it goes.

 

Is it just infrequent enough that we haven't observed it? And why wouldn't the volcanoes be enough to relieve the pressure?

[metadigital]

Not only does it rotate backwards, it also has no tectonic plates.  The thing has to have a molten core because of it's size, but no apparent way to exchange the heat.

<{POST_SNAPBACK}>

Yeah, but the whole surface of the planet is less than half a million years old (might not be correct figure, no time to look it up: just extemporizing here), meaning that the pressure likely builds up until a critical point at which time there are super eruptions all over the planet to release the pressure and the result is a new blanket of granite / basalt over the surface of the planet ... wait a few thousand years and the surface cools again, and the rince and repeat.

 

[taks]

Err, just a clarification...what exactly do you mean when you say "specific" wavelength.  Are you implying that only 1 specific wavelength gets absorbed?

there's actually a band of wavelengths.

 

Also, are you taking into consideration that anything that doesn't get absorbed, gets reflected (think back to your example with the blinds.  Much of the light is reflected back)?

that which is reflected doesn't contribute to the heat of the earth. the effect of CO2 is to trap heat that would otherwise be reradiated.

 

I also disagree that 75% is near it's peak, especially consider that that number is an absolute value.

yes, it is near it's peak. given that this absorption is only a small percentage of the total heat of the earth, 25% remaining means we can only trap enough heat to warm the planet a very small amount further.

 

I'm confused here, why is reaching the peak in Venus result in the runaway greenhouse effect, whereas ours won't?  Not sure what citing the CO2 values means anyways, as the theory is that, with a runaway greenhouse effect, your CO2 values will explode.  Not all that shocking that after it occurs, the atmosphere is 96%.

because venus started out with a much higher concentration in the first place. remember, venus' atmosphere is 90 times denser than ours. apples-apples comparisons aren't valid. also, given that CO2 is already at a 75% of its peak contribution anyway, and given that it is a bit player, CO2 alone cannot cause such a runaway. in the end, it will be up to the water vapor to pull off a runaway.

 

This of course overlooks the fact that water vapour played a key role in Venus, as well as the fact that water vapour is the primary contributor to Earth's greenhouse effect.

<{POST_SNAPBACK}>

this is why 75% of CO2's possible contribution is significant. it is only a bit player anyway.

 

taks

[taks]

btw, just the fact that a few of the distant past ice ages had CO2 concentrations more than 10x than now are good indicators that CO2 isn't what's forcing changes. also evidence is that historical guesses at temperature changes, while correlating to CO2 concentrations on average, typically precede CO2 by 800 years or so. in other words, it seems that when the earth warms, we get more CO2, not vice versa. this makes sense if you recall that the ocean is the primary CO2 since (as noted by alanschu as well). heat the ocean and you get more evaporation, which results in more water and also more CO2.

 

now, how this 2nd part jives with ice cores showing 10x concentration during an ice age is beyond me. maybe it just means that ice cores are really a poor method of determining past CO2 concentrations (there is evidence that this may be true, i.e. ice cores bad)? or, maybe warming and cooling do cause changes, but there are other factors as well that will dominate even during an ice age.

 

taks

Edited May 26, 2006 by taks

[LoneWolf16]

Probably makes absolutely no sense whatsoever...but maybe a really high level of CO2 is what sets the cycle in motion, moving from a period of more warmth to an ice age with the remaining CO2 being absorbed into the ice during its freezing, which eventually bleeds away as the atmosphere rebalances itself?

 

I have no idea. Random flailing stab in the dark.

[metadigital]

Noted.

 

Actually, it's only about half a billion years ago that the Earth formed the oxygen-rich (20%) atmosphere; before that it was a lot less hospitable ... unless you are an an

[astr0creep]

Noted.

 

Actually, it's only about half a billion years ago that the Earth formed the oxygen-rich (20%) atmosphere; before that it was a lot less hospitable ... unless you are an an

[metadigital]

Although cause-and-effect is notoriously dificult to determine, the switch to the current nitrogen-oxygen mix caused the very rare event that caused the ATP to become symbiont with single cell organisms, thus providing the lauchpad for the multi-cellular diversity we enjoy in our modern ecosystem.

[taks]

yup... and yup. not sure about lonewolf's statement, however.

 

the ice ages are more than likely triggered by the wobble of the earth's axis w.r.t. the plan in which we orbit the sun. there are also some issues with our movement through the galaxy as a whole and probably a host of other things that we haven't even begun to consider. i'm betting a lot on the sun and it's cycles, which can be devastating (look up maunder minimum).

 

taks

[LoneWolf16]

Eh, like I said. "I have no idea. Random flailing stab in the dark."

[alanschu]

yup... and yup.  not sure about lonewolf's statement, however.

 

the ice ages are more than likely triggered by the wobble of the earth's axis w.r.t. the plan in which we orbit the sun.  there are also some issues with our movement through the galaxy as a whole and probably a host of other things that we haven't even begun to consider.  i'm betting a lot on the sun and it's cycles, which can be devastating (look up maunder minimum).

 

taks

<{POST_SNAPBACK}>

 

 

I would think the galaxy fluctuations would be pretty insignificant, given their distances. THough I guess there IS a whole lot of galaxy out there to make our ginormous distance less important. But it is r^2

 

 

there's actually a band of wavelengths.

 

Ok good. I didn't like the word "specific" so I was just clarifying exactly what you meant.

 

that which is reflected doesn't contribute to the heat of the earth. the effect of CO2 is to trap heat that would otherwise be reradiated.

 

Then what happens to the reflected energy?

 

because venus started out with a much higher concentration in the first place. remember, venus' atmosphere is 90 times denser than ours. apples-apples comparisons aren't valid. also, given that CO2 is already at a 75% of its peak contribution anyway, and given that it is a bit player, CO2 alone cannot cause such a runaway. in the end, it will be up to the water vapor to pull off a runaway.

 

Is Venus' higher density atmosphere cause or effect? I'm sure if we had a runaway greenhouse happen, our atmosphere would be quite a bit more dense as well, given the fact that CO2 has more mass than Nitrogen.

 

As for the CO2 concern, the concern isn't that CO2 alone is going to cause a runaway, but rather incremental increases will result in additional heating, which would result in increased water evaporation and so on.

[Colrom]

I hope the prognostications they are using for future CFC releases and the results they model for atmospheric ozone are accurate - but it would be prudent to read about contrary opinions before celebrating.

 

There are alot of scientists who will accept a grant with a biased premise and publish BS for pay.

 

Many countries have weak restrictions on the corporate users. You know - they are supposed to be good on their honor - but who knows?!

 

It may be difficult to actually know what is produced, what is released, and what is destroyed, even when folks are more or less truthful.

 

The lifetimes of some of these molecules in the atmosphere are very long - like 70 or more years - so misunderstandings may project consequences quite far into the future.

 

I wonder what will happen before the projected turnaround?

 

[Fenghuang]

If it escapes, it must have quite the escape velocity, unless maybe it somehow breaks down molecularly.

 

I'm not disputing that it somehow becomes gaseous, but rather what happens to it when it goes.

 

Is it just infrequent enough that we haven't observed it?  And why wouldn't the volcanoes be enough to relieve the pressure?

<{POST_SNAPBACK}>

 

 

Actually I just remembered I got the two programs mixed up. The one on Earth did have escaping matter, but I remember a fancy Animamation from the Nova program the described something similar to what Mets said.

 

Though rather than eruptions they proposed the the crust goes all melty and the old pieces of rock break up and sink while new stuffs rises. This probably makes more sense than what silly little me said.

[taks]

THough I guess there IS a whole lot of galaxy out there to make our ginormous distance less important.  But it is r^2

you're thinking of directly radiated energy from a point source. that speaks nothing of the various patches of whatever we may pass through along the way.

 

I didn't like the word "specific" so I was just clarifying exactly what you meant.

well, it is very specific, and very narrow actually, though plural would have sufficed.

 

Then what happens to the reflected energy?

space, the final frontier.

 

Is Venus' higher density atmosphere cause or effect?  I'm sure if we had a runaway greenhouse happen, our atmosphere would be quite a bit more dense as well, given the fact that CO2 has more mass than Nitrogen.

probably both. it started out denser i'm sure, and then went all kablooey and got worse.

 

As for the CO2 concern, the concern isn't that CO2 alone is going to cause a runaway, but rather incremental increases will result in additional heating, which would result in increased water evaporation and so on.

<{POST_SNAPBACK}>

given how much warmer things have been in the past, and how much more CO2 AND water vapor have been in the atmosphere, i think it is relatively safe to say the runaway scenario isn't plausible. possible, maybe, but not plausible.

 

the problem with the average scare tactic is that it places ALL of the blame on man caused CO2. unfortunately, we're not even sure CO2 is rising entirely because of human emissions. this whole "science" is dubious at best.

 

taks

[alanschu]

you're thinking of directly radiated energy from a point source. that speaks nothing of the various patches of whatever we may pass through along the way.

 

Outside of our collision course with the Andromedia galaxy, I suspect that the exceptionally cold dust of nebulae and whatnot are rather insignificant.

 

space, the final frontier.

 

Uh, come again? The Earth is a black body emitter, particularly in the low infrared (which happens to be the range the CO2 absorbs). If the CO2 starts blocking it, and it's not absorbed by it because it's reached its threshold, it's not escaping into space, unless it converts to a different wavelength (which would result in something absorbing or giving that photon energy).

 

How can it get into space if it can't get past the CO2 wall? Hence why I mentioned reflected energy, because the energy emitted from the Earth would be reflected off of the atmosphere as it tried to escape Earth, back down to Earth.

 

the problem with the average scare tactic is that it places ALL of the blame on man caused CO2. unfortunately, we're not even sure CO2 is rising entirely because of human emissions. this whole "science" is dubious at best

 

This I won't dispute as I agree with it wholeheartedly.

 

Though I'm enjoying the discussion about the plausibility of a runaway greenhouse.

[metadigital]

(look up maunder minimum).

<{POST_SNAPBACK}>

*looks up Maunder minimum.

 

Thanks!

 

Also things like Krakatoa had an impact ...

[Colrom]

So Taks, are you published on this matter?

 

What publications have you read recently which support your contention that this global warming stuff is still under debate by scientists?

 

I thought the debate was over among the reputable scientists and it was agreed that civilization is having a significant and decisive impact on global warming.

 

Just wondering.

[213374U]

If you ask for proof, the least thing you should do is provide your own evidence to support your own claims...

[alanschu]

So Taks, are you published on this matter?

 

What publications have you read recently which support your contention that this global warming stuff is still under debate by scientists?

 

I thought the debate was over among the reputable scientists and it was agreed that civilization is having a significant and decisive impact on global warming.

 

Just wondering.

<{POST_SNAPBACK}>

 

 

Scientists were also concerned with Global Cooling throughout the 70s.

[metadigital]

I heard about some critical chemical reaction in the atmosphere that keeps the basic, fundamental chemistry of life working (can't remember details now: it was in New Scientist about ten years ago) that breaks down at an (unknown) higher temperature ... something about convection and ions and gases or somesuch.

 

Colron, I have a (very intelligent) friend who is adamant that global Warming is a myth: he has recetly bought me The Skeptical Environmentalist

and State of Fear

to read (yes, I pointed out that the latter book is fiction: it was the source of much merriment on my part. )

 

I'll let you know what I think when I've read it; my understanding (which I would say with as little hubris as possible is far superior to his) is that there is a consensus that the Earth is warming, and that human activity has some impact on it: the magnitude of the impact (and the underlying warming trend, which may or may not be completely natural and many measures of magnitude larger than the human contribution) are yet to be determined.

 

He still argues that theworld is not warmer than it was, which I dispute. No-one can say for certain what has caused any warming, with any certainty, yet.

[alanschu]

The Appendix of State of Fear was a very interesting read.

[metadigital]

I will have to read it soon, because he will not let me not read it for much longer (even though he lives on the antipodes fo the planet).

 

Crichton normally researches his novels well (Andromeda Strain, ER, etc), which is my friend's argument; I am still very skeptical, myself.

[alanschu]

The impression I get from the Appendix is that that is indeed the case.

 

He may be a fiction writer, but his settings make more sense if he's not completely off the wall with some of the science behind it.

 

I think he did his homework. I haven't actually read the book (just the appendix), though my roommate has highly recommended it.

Edited May 28, 2006 by alanschu