Antarctic Ice Sheet Collapse

[Berzerker]

according to this link, sea levels were 4-6 meters higher in a prior interglacial 125 kbp

http://www.giss.nasa.gov/research/briefs/gornitz_09/

 

[unscratchedfoot]

There's a swimming warning for the general Antarctic region. A few people swimming there have been mashed between the chunks of colliding ice sheets as they tend to loosen up in sudden shifts.

 

[brennan]

...our sister planet, which is at the same time a symbol of love and the physical embodiment of Hell (a splendid bit of poetic truth there), proves my position very clearly. Greenhouse gases exert an insulating effect. The effect of insulation is to slow down and moderate changes in temperature.

You keep saying this but it overlooks the fundamental and rather important fact that insulation prevents loss of heat. Which is why Venus is indeed the embodiment of Hell: increasing the insulation of a planet heats it up - you change the rate at which the planet loses energy but the input remains the same. Insulation does not 'slow down and moderate warming', it is the cause of it. The moderation of extremes you are going on about occurs because the increased energy in the system leads to an increase in the rate of entropy - it drives the mixing process faster IOW more insulation leads to more heat leads to better mixing, not more insulation leads to better mixing leads to more moderation, which is your erroneous (as usual) model.

And your conclusion:

Bitter-cold winters and scorching summers may be the price we have to pay to avoid seeing the oceans rise by five meters.

Well that's the routine we used to be in. We may well be leaving it (due to our own activities), which is why we are concerned, see?

 

[Ziggy Stardust]

You guys are two of the reasons I'm skeptical of global warming. This is like the third time in a row I've stared blankly at the screen and gone "oh, come ON, I can't believe he asked that".

You can't believe something slipped someones mind. I admitted I was mistaken, what more do you want? Allthough I could see why you would stare blankly at the screen seeing someone admit he's made a mistake. Must seem very alien to you.

Now you know how I feel when you trot another one of your goofy unsupported theories out as it being the pinnacle of scientific research.

 

[Berzerker]

You keep saying this but it overlooks the fundamental and rather important fact that insulation prevents loss of heat. Which is why Venus is indeed the embodiment of Hell

Venus is upside down, not spinning with no magnetic field to protect the surface... You cant compare a dead planet with the Earth.

 

[BasketCase]

You keep saying this but it overlooks the fundamental and rather important fact that insulation prevents loss of heat.

And you're overlooking the fact that insulation also keeps heat from getting in. Without insulation, the Earth's surface on the day side would be hot enough to boil water right now.

Insulation slows down and moderates warming. And yes, in the long run, does produce more warming. But moderation can be bad all by itself. So you think global warming is going to happen--all this stuff about insulation doesn't change that answer. But if that warming does happen, what will the early symptoms be? I'm talking long before the oceans start rising--that will take a couple centuries, minimum. What will we see short-term? What will be the warning signs? More violent weather or less violent weather? More extremes of hot and cold, or warm winters and mild summers?

Well that's the routine we used to be in. We may well be leaving it (due to our own activities), which is why we are concerned, see?

No. Warm winters and mild summers are something we humans want. It's the reason we always gather at coastlines--because the sea makes great insulation. Moderates the weather.

What we humans do is notice everything unpleasant, and make a Doomsday scenario out of it. And that's what the global warming mantra is: more extreme winters and summers. More violent weather. Rising seas. Devastation of crops. Increased desertification. Absolutely everything we hate. We see all the things that are bad about the weather and roll it into one big rotten ball of garbage.

Nature doesn't care what we want. Global warming will be some good things and some bad things, who knows how much of which. Almost certainly rising seas. Probably some parts of the Earth will become less habitable (i.e. desert)--but definitely other parts of the planet will improve. And outside of that we have no idea. Maybe calmer weather. Probably more bountiful harvests. Loss of some species--and creation of new ones.

The kicker is that we don't know which of the above will happen. That's actually what scares us. Even change for the better is terrifying.


Edit: Also, high-five to Berzerker for five posts in a row.

 

[brennan]

And you're overlooking the fact that insulation also keeps heat from getting in.

Wrong. Insulation doesn't prevent heat from getting in; it slows the rate of heat transfer. And in our specific case the greenhouse effect tends to let heat in but doesn't let it out again producing a net warming effect.

What will we see short-term? What will be the warning signs? More violent weather or less violent weather? More extremes of hot and cold, or warm winters and mild summers?

More extremes. Which is what we are seeing. Compare with Venus again, which experiences very high wind speeds and enormous storms in the upper atmosphere (lower down the atmosphere is too dense for this)

No. Warm winters and mild summers are something we humans want. It's the reason we always gather at coastlines--because the sea makes great insulation. Moderates the weather.

I have no idea why you said this.

 

[bathsheba666]

I'm impressed by BasketCase's strategic clarity of thought and relevance.

 

[brennan]

Venus is upside down, not spinning with no magnetic field to protect the surface...

And precisely what significance do those two facts have?

None.

 

[Dr Tiny]

A lot of discussion about Venus which I have found interesting. I decided to do some research so I could learn a bit more about things. Here are some planetary temperatures.
Mercury
Max 427C
Min -183C

Venus*
484C

Earth
Max 40C
Min -70C

Moon
Max 214C
Min -184C

Mars
Max 22C
Min -125C

*Venus is isothermal ie the surface temperature is constant day v night and equator v poles.

The moon recieves almost the same ammount of sunlight as Earth, but its lack of atmosphere causes the wild variations in temperature as heat can not be retained, similary it has no way to block energy arriving from the sun.

Marcury and Mars have very thin atmospheres and also have relativly large variations in temperature.

Venus has a very thick atmosphere ([CO2] >95%) which has several effects
1 - Significant heat retention, compare the temp of Venus to that of Mercury despite Mercury recieving 4 or 5 times as much solar irradiance as Venus. In addition Venus has a high albedo and very little light energy penetrates the atmosphere, but almost all of it is retained.
2 - Efficient mixing of the temperature resulting in the isothermal conditions.
3 - Apparently, according to wikipedia, if there was no CO2 based warming effect happening on Venus then it would have a surface temperature range similar to Earth.

I found the data by just googling, I cant be bothered to post the links...sue me

 

[Shaihulud]

Most of the climate scientists have agreed that global warming is taking place and not for the better. records and what we know of human activity strongly indicates that it is due to human industrialization. It is almost certain that Earth has a cyclical pattern of climate changes, as should any big systems, but it may have moved out of normality. I have read most of the evidences for global warming, on a cursory read they make sense, i therefore agree with global warming. I can't see a world wide conspiracy of scientists trying to fool everyone including themselves.

 

[MrCynical]

And you're overlooking the fact that insulation also keeps heat from getting in. Without insulation, the Earth's surface on the day side would be hot enough to boil water right now.

The snag there is that heat is arriving and leaving the Earth in somewhat different forms, so the insulator is not equally effective at keeping heat in and out. Energy arrives from the sun as photons in the visible and near visible regions of the spectrum, which CO2 (for example) is largely transparent to. Heat from the Earth generally leaves as photons in the infra red part of the spectrum, which CO2 absorbs very well - hence it keeps heat in, but not out.

There are gases with other absorption properties, and which do keep heat out to some extent, but greenhouse gases by definition are not these. Hence you're dumping a gas which essentially only lets heat in into the atmosphere- not going to lead to moderation.

 

[bhsup]

So then we just need a few big photon converters to switch them from IR to visible light. Shouldn't be too hard to make something like that.

 

[Berzerker]

And precisely what significance do those two facts have?

None.

You brought Venus up, not me. I just explained why you cannot compare Venus to Earth and you think that aint relevant - it is. The fact you dont know that speaks volumes...

 

[BasketCase]

Just had another brainstorm. Therefore, before reading any of the latest posts:

Who said greenhouse gases should have anything to do with the Sun at all?

Insulation only keeps you warm because your body is a natural heat source. When you insulate something that's not a heat source, you get exactly one effect: that object takes longer to heat up or cool down to the surrounding temperature.

Guess what, the Earth is a natural heat source. Of course, the planet's molten interior is considerably less spectacular than a self-sustaining thermonuclear bomb, but what the hey. Anyhow, if you find a deep enough underground cave, you'll discover that the Earth's subsurface temperature hovers somewhere around fifty degrees Celsius. Year-round. With almost no measurable change; the Sun's energy doesn't reach that far down.

Greenhouse gases will also act to prevent that heat from getting out. So there ya have it. The Sun may not even be a factor--the thicker blanket of carbon dioxide may be warming the planet up from the inside.

 

[BasketCase]

Venus is upside down, not spinning with no magnetic field to protect the surface... You cant compare a dead planet with the Earth.

Our sister planet is still very useful in an important way.

According to Wikipedia, if it weren't for all that carbon dioxide in Venus' atmosphere, its surface temperature would not be significantly different from Earth's. So we have a single point of difference that we can use to examine the effect of increasingly dense greenhouse gas blankets.

Venus' atmosphere is not only almost entirely carbon dioxide, but it's a hundred times more dense than Earth's atmosphere. A one-mile an hour wind on Venus will blow you around like a tumbleweed. Venus' carbon dioxide blanket is thousands of times thicker than Earth's.

Yet Venus is not thousands of times hotter. It's about three times hotter. What this shows is that as you pour more carbon dioxide into the atmosphere, each successive cubic kilometer warms the planet less than the previous cubic kilometer.

If the Earth didn't have any carbon dioxide in its atmosphere, it would be something like thirty degrees colder. Add two hundred parts per million of CO2 (which is about where the Earth was before humans came along), and you get thirty degrees of warming. But what Venus shows us is that if we humans add that same amount of CO2 again--another two hundred parts per million--we cannot get another thirty degrees of warming. You're going to get far less.


Venus disproves one of the basic mantras of global warming alarmists. We're getting diminishing returns from all the extra greenhouse gases we're spewing.

 

[BasketCase]

The snag there is that heat is arriving and leaving the Earth in somewhat different forms, so the insulator is not equally effective at keeping heat in and out. Energy arrives from the sun as photons in the visible and near visible regions of the spectrum, which CO2 (for example) is largely transparent to. Heat from the Earth generally leaves as photons in the infra red part of the spectrum, which CO2 absorbs very well - hence it keeps heat in, but not out.

The Sun emits at just about every frequency--there is a substantial amount of heat coming in, and CO2 does prevent a lot of that from getting in. What happens is this: when sunlight hits the ground, some of it gets absorbed. The laws of physics state that energy emitted will always be at a lower frequency than it was when it was absorbed, so when it comes back out it's going to be closer to (or in) the infrared range. That infrared radiation will have trouble getting out.

It's all a question of how much gets in/out and how much is blocked.

 

[skadistic]

http://heartland.temp.siteexecutive.com/pdf/22835.pdf

Hmmmmmm what was that about consensus for man being the cause?

 

[BasketCase]

Wrong. Insulation doesn't prevent heat from getting in; it slows the rate of heat transfer.

Ohhh, you wanna play fling-the-dictionary again, eh? I'm game.

Incoming solar radiation is absorbed by CO2 in the upper atmosphere and radiated back into space. Heat is prevented from getting in. I never said ALL of it is prevented from getting in.

FLING!

Your turn.

 

[BasketCase]

You can't believe something slipped someones mind. I admitted I was mistaken, what more do you want? Allthough I could see why you would stare blankly at the screen seeing someone admit he's made a mistake. Must seem very alien to you.

Actally, seeing somebody admit a mistake is extremely rare in online message boards, but that's not it.

My beef is that you do this ALL the TIME. You're always ignoring really basic stuff in order to get the questions out. I have no problem with somebody going all Devil's Advocate on my ideas, but you go way overboard. Brennan is even worse.

Now you know how I feel when you trot another one of your goofy unsupported theories out as it being the pinnacle of scientific research.

They're not pinnacles. They're just ideas. But they are pretty well-supported because I start out from what I know.

Global warming alarmists start from what they fear. Wrong way to do it.