Mars melt and Global Warming

[Shabaz]

They're under embargo? They were handing out copies at the Royal Society yesterday.

Well, I don't believe that the full AR4 WG1 report has been finalized yet, and so the only form it is out in yet is a draft form (a pretty close to final draft though, since it needs to be in a certain state to allow the WG1 SPM to be based on it), and the draft has the standard caveats that it shouldn't be quoted or cited or be redistributed before the IPCC published the finalized version. Don't know if embargoed was the proper word to use there, but far as I know the full report proper hasn't been released yet by the IPCC. Anyway, I can see them being ok with the Royal Society having a discussion talk on it and passing it around, but the place I got it from was obviously and explicitly breaking the embargo, which made me a bit uncomfortable with my own actions.

 

[Diamond]

Then how can you say that high CO2 concentrations are incompatible with ice ages? What if the sun's luminosity was 10% lower than now? In fact, the sun was dimmer in the past.

I'm not the one claiming that CO2 concentrations rising "enhance the greenhouse effect" and lead to warming. The Sun was dimmer in the remote past as its should as a main sequence star.

But the Earth's climate was warmer 1000, 2000 and 6000 years ago. None of it was due to carbon dioxide rise yet somehow this tiny change in mean temperature is not due to natural variation but due to anthropogenic carbon dioxide.

Evidence?

Never? Evidence?

Yep. Never. Never has carbon dioxide rise preceded temperature rise. All of the ice cores show the delayed effect. Every one. Without exception. A fact that you don't bother to dispute.

This graph seems to show a good correlation between CO2 levels and temperature (glacial periods).

The Freeserve Brighton Website - the well known scientific resource.

The badly drawn chart isn't high enough resolution to show which comes first - but the high resolution ones all show the delayed response of carbon dioxide to climate warmth.

Also, how do you explain the Paleocene-Eocene Thermal Maximum?

What has that got to do with anything? Did it have anything to do with greenhouse gases PRECEDING the rise? No.

It has no more to do with climate change than the 2000ppm carbon dioxide level of the Ordivician Ice Age.

A physical system will never "warm or cool for no reason at all", linear or not. It would violate energy conservation, for a start.

In particular, for the Earth's oceans and atmosphere to warm up requires a large input of energy. What do you propose is the source of this energy?

Now we know you're out of your depth. The ocean-atmosphere system is not in equilibrium - its a "loosely coupled non-linear system". As such, non-linear systems can rise and fall without any major parameter change. It does not violate energy conservation at all since its major energy input is continuously varying on multiple time scales, as well as its outputs.

 

[shanek]

The "peak" that you refer to is the current interglacial (the Holocene), which are the warm periods that intersperse the colder glacial periods. The current interglacial has lasted about 10 000 years, and the temperature changes over various intervals can be found here.

Yes, but according to the graph, while ice volume is comparable, the temperature graphs are lower than the previous interglacials. So something else has been happening this time around, and for much, much longer than just the current warming.

I'm not sure why we should be expecting glaciers to be melting now, based on the glacial/interglacial cycles. If anything, we should be heading for another glacial period, but according to this, not for another 50 000 years (if ever, our CO2 emissions will probably change things).

Well, I'd say not heading into another ice age is a good thing. I imagine there'd be a lot more problems with Global Cooling than with Global Warming.

 

[shanek]

The Earth is no way near as hot as the Sun, so that's where the long-wavelengths come in (or go out).

I don't understand. Why should the Earth be as hot as the sun under what he's saying? I for one am glad it isn't; the summers around here are bad enough. But we get only the tiniest portion of solar radiation output by the sun; the rest of it goes elsewhere in space. Not even Mercury, with its one face always towards the sun, gets as hot as the sun does.

 

[shanek]

Would it suprise you to know that during some ice ages, there has been more CO2 in the atmosphere?

Would it suprise you to know that in the past the atmosphere was at least 50% CO2 (a lower limit for the period, based on evidence .. btw, 50% = 500,000 PPM)

Facts such as these begs the question of how significant the 380 PPM figure is.

I totally get what you're saying, but being more of an economics geek I understand the idea of ceteris paribus, which seems to apply here in spades. Increased CO2 concentrations can, if all other things are equal, cause atmospheric warming; this doesn't mean that there aren't a thousand other forces that can cause atmospheric cooling at the same time.

While 380 PPM is certainly higher than it was 500,000 years ago, we do have evidence of what the planet was like when it was much higher than it is. We know that the green house effect did not 'run away' with itself due to a mere 380 PPM, or 1000 PPM, or 10,000 PPM, or even 100,000 PPM. This is Earth, not Venus.

I agree that the runaway Venusian-like greenhouse effect is bad science, but I haven't seen anyone in this thread posit it.

I absolutely think there's something else going on, and seeing the graphs and data given in this thread confirms it. We're at the peak of low ice volumes without being at a comparable peak in temperatures, looking over the last 10,000 years or so. So something is different now than it was the last 4 or 5 times the Earth went through this, and unless the ancient cave-painters had SUVs I'm pretty sure it's not due to pollution.

 

[shanek]

I found this on the issue of temperatures preceding CO2 rises:

What does the lag of CO2 behind temperature in ice cores tell us about global warming?

At least three careful ice core studies have shown that CO2 starts to rise about 800 years (600-1000 years) after Antarctic temperature during glacial terminations. These terminations are pronounced warming periods that mark the ends of the ice ages that happen every 100,000 years or so.

In other words, CO2 does not initiate the warmings, but acts as an amplifier once they are underway. From model estimates, CO2 (along with other greenhouse gases CH4 and N2O) causes about half of the full glacial-to-interglacial warming.

So, in summary, the lag of CO2 behind temperature doesn't tell us much about global warming. [But it may give us a very interesting clue about why CO2 rises at the ends of ice ages. The 800-year lag is about the amount of time required to flush out the deep ocean through natural ocean currents. So CO2 might be stored in the deep ocean during ice ages, and then get released when the climate warms.]

 

[Cuddles]

Surely it is obvious to everyone that global warming is due solely to the decline in pirate numebers.

 

[shanek]

So, then, do we have brief Global Cooling every year on International Talk Like A Pirate Day?

 

[rockoon]

OK, I'm new here, and I don't know your posting history or his. But you seem to be doing a lot of interpreting on just a couple of words from him

Not just a couple words. Multiple posts with different wording all claiming the same thing is not a couple words.

I dunno, maybe you expect him to say such things as "380ppm is unprecedented in all eternity" based on past experience with him, but I didn't see him making such overstatements in this thread.

I expected him to say what he meant. AFAIK, he did. What he said is a lie.

And to answer the question to the best of my knowledge: it's pretty significant. I'm not quite sure what you're saying here, that the rise to 380ppm is not because of us, but because of natural processes?

I am saying we cannot simply assume that it is likely to be significant like you might if it was "uncharted territory." The climate is likely to be similar to the last time, the time before that, the time before that, and so on.

That CO2 won't have the amount of climate forcing it is said to have?

It will likely have the same amount of forcing as last time. CapelDodger claimed there was no last time.

Why is this so hard to comprehend?

Just to be clear, he didn't use the word unprecedented, that was me.

Yes, I was responding to you. And to be clear, I didnt attribute it to neither him nor you.

And the type of very rapid introduction of a massive amount of CO2 as we're doing now, I think that could be validly described as moving us into uncharted territory.

Now I think that you may be making an assumption dangerously similar to his. What is the source for this assumptiuon?

I guess I missed where someone said or implied that the green house effect would run away or that earth would turn into Venus in this thread.

I did not attribute that to him, or you. It is one potential likely scenario that is often raised when one believes that CO2 was at unprecidented levels.

It is hard to imagine it happening when CO2 is not anywhere near unprecidented levels, however. That was my point.

Why can we not conclude any predictive power from models? Which models have been shown to be dangerously close to a "self-weighting strategy"?

They don't need to be shown to be. Until models are proven to be predictive, we must assume this. This is a central tenant in science.

As a simple example there are an infinite number of potentially correct string theory models. Only one, if any at all, can be correct. Only the models that prove themselves predictive could be considered potentially correct. Just like string theory where no predictions have been verified, the same is true of climate models where no predictions have been verified. There is an infinite number of climate models that would match a finite set of past data as well.

We would be guessing as to the correctness of any of these models because we do not have evidence to suggest that one should be prefered over another. We don't even know if ANY of the current models will prove predictive.

And why are you implying that the tests that are held in the past records are not exactly what is used to validate or falsify GCMs?

Past records can only be used to falsify. They cannot be used to "validate."

Or has it been shown that their methods of validation are in error?

If they are "validating" with prior samples, then they are in error. I do not think that the people involved in climate models are claiming that they have been validated. I think the media, as well as posters on forums and blogs, are likely to gloss over such issues or even incorrectly report it.

 

[rockoon]

Sorry to be the cite monkey, but can you give me one that gives evidence that earth's atmosphere once had CO2 levels higher than 1000 ppm?

Nature 2004, Volume 428, Issue 6984

Let me know if you find fault with Hessler, Lowe, Jones and Bird.

Additionally

http://www.space.com/scienceastronomy/planetearth/earth_archaean_010716.html

 

[RichardR]

This is one of the kinks in their armor, so your not likely to get an answer. They will ignore it or say it didnt happen.

Wrong.

 

[Diamond]

I found this on the issue of temperatures preceding CO2 rises:

What does the lag of CO2 behind temperature in ice cores tell us about global warming?

Unfortunately, SurrealClimate fails to explain a) why temperature rise causes carbon dioxide rise but never the reverse b) why temperatures can fall while the carbon dioxide level continues to rise and c) why the supposed "feedback" appears to be non-existent.

What the lag means is that "Greenhouse Warming" is simply wrong. It also means that the forcing supposed in climate models is magnitudes too large. Whatever is causing the temperature to rise and fall, it isn't greenhouse gases.

 

[Diamond]

Wrong.

Unfortunately, that article is exactly the kind of straw man argument you get from SurrealClimate. The many statements which are false obscure that the argument is fallacious.

 

[RichardR]

Unfortunately, that article is exactly the kind of straw man argument you get from SurrealClimate. The many statements which are false obscure that the argument is fallacious.

But since you can't name any of them, I think I'm happy to let anyone who is interested actually read the RealClimate link and decide for themselves. Thanks for your reasoned and valuable input though.

 

[a_unique_person]

The notion that CO2 is in such a balance is yet another handwaving argument put out by the climate modellers of SurrealClimate. Its an assumption made to facilitate their careers and their future funding - to suppress the natural variation of climate by rewriting the past. Temperature change? Never happened. Carbon dioxide change? An Exxon funded lie. Solar variation? Et cetera...

More conspiracy theory.

Getting back to Mars, why are the polar caps melting (or subliming to be more precise)? Why is Pluto warming even though its moving further away from the Sun in its elliptical orbit? Why is Triton?

You raised the point, why don't you tell us?

 

[shanek]

But since you can't name any of them, I think I'm happy to let anyone who is interested actually read the RealClimate link and decide for themselves. Thanks for your reasoned and valuable input though.

Well, I must say, while I didn't see any falsehoods in the article, it did leave me wanting. I mean, they're saying you can expect CO2 concentrations increase after a warming period because of yadda yadda yadda. Fine. But, we're about that same amount of time after the MWP. So shouldn't it not be a surprise that they're increasing now? I know, I know; the MWP was just a European/North American phenomenon. But then, most of the CO2 increases are coming from Europe and North America.

 

[CapelDodger]

Well, I must say, while I didn't see any falsehoods in the article, it did leave me wanting. I mean, they're saying you can expect CO2 concentrations increase after a warming period because of yadda yadda yadda. Fine. But, we're about that same amount of time after the MWP. So shouldn't it not be a surprise that they're increasing now? I know, I know; the MWP was just a European/North American phenomenon. But then, most of the CO2 increases are coming from Europe and North America.

A major component, quite possibly the dominant component, of the atmospheric CO2 increase is due to release of CO2 from warming oceans. Other things being equal, warmer water dissolves less CO2 than cooler water. The release of CO2 from the oceans reduces the CO2 content of the oceans and increases the atmospheric content. An equilibrium is reached when the relative CO2 contents of oceans and atmosphere are in balance at the prevailing temperatures. In this case CO2 is acting as a feedback to warming initiated by other processes. Just as a wetter atmosphere is a feedback to warming initiated by other processes.

The CO2 content of both the oceans and the atmosphere are increasing at the moment. That can be, has been, and continues to be directly measured by reasonably sensitive techniques. The 800-year lag during the warming at the end of a glaciation and beginning of an inter-glacial has no bearing on current events. CO2 is being absorbed by the oceans, not released from it. The warming influence that tends to expel CO2 is being outweighed by the influence of the increased over-pressure of CO2. Up from a range of 180-300ppm over at least the last 600,000 years to 380ppm in a century or so. Coinciding with very evident warming. As one would expect, after all.

There's no salvation in the past. This is uncharted territory we're in.

 

[CapelDodger]

But since you can't name any of them, I think I'm happy to let anyone who is interested actually read the RealClimate link and decide for themselves. Thanks for your reasoned and valuable input though.

Diamond's a sucker for puerile whimsy like "SurrealClimate". He doesn't need to read stuff first-hand when he can read comment on how stupid "they" are backed-up by out-of-context quotes. Also how mendacious, inept and/or corrupt "they" all are. And stupid, don't forget stupid.

 

[lenny]

A rational debate on the subject would consider similar circumstances in the past. This is especialy important when we cannot directly test the theories on the table. The past holds a record of repeated tests for us.

evidence please:

dates of the higher concentration and the quality of the obs relative to the current satellite record; or the instrumental record; or high sampling rate proxies that overlap with the previous two?

We have actual data to work with and we shouldn't ignore it (or declare that it doesnt exist.)

what actual (quantitative, high time resolution) data do you mean? early earth had huge CO2 levels pre-life; we have little data there for you to use against CapelDodger, presumably you have something more relevant than this kind of technical nitpick???

 

[lenny]

They don't need to be shown to be. Until models are proven to be predictive, we must assume this. This is a central tenant in science.

if that really were a central tenet of science, not much geophysics would make the cut. and even if a model were shown to be "predictive" out-of-sample (on new data), it would fall to Hume's skeptical arguments.

weather forecast models are not "proven to be predictive" but they are demonstrated to be of value.

by construction, climate change modelling is extrapolation, a model can never be "proven to be predictive" in extrapolation.

so i am curious: are you tending toward to argument that, by construction, climate questions can never be answered?

or are you merely stating that you do not believe todays state-of-the-art models are sufficient?

or are you bogged down in that un-identifiability distraction of philosophers: that we could never identify the "perfect model" even with vast accurate observations?