Mars melt and Global Warming

[Diamond]

Where did that come from?

Far as I know he's absolutely right in the claim that there wasn't a C02 concentration of 380ppm until fairly recently. I suppose if you take his statement as him saying that 380ppm is absolutely unprecedented in the history of the planet and then go far back enough it might've happened before, but with a more common sense interpretation of what he was saying he really wasn't misrepresenting the data we have on atmospheric CO2 concentrations.

To copy-paste another IPCC AR4 SPM chart:

What you're looking at are composites. The top one is the Siple Curve shifted 83 years to the Moana Loa CO2 meaurements so as to produce a single curve.

But no-one knows how the Siple curve was produced and how many readings above the "pre-industrial" 280ppm they erased to get the curve.

There is good evidence that ice cores are artificially deficient in carbon dioxide because of the properties of the ice the gases are found in. Other techniques such as from plant stomata, show that 6000 years ago, the CO2 concentration was ~350 ppm.

The modern value for carbon dioxide concentration is abnormally low in geological history. For long periods in the past, carbon dioxide levels were 10-20 times their current level, and were much higher even during million-years-long ice ages.

 

[a_unique_person]

More conspiracy theories.

 

[Brian the Snail]

Then they're a long way from proving it.

There is no such thing as "proof" in Science.

Greenhouse gas emissions don't account for the 1940-1977 cooling,

No, but sulphate aerosols and changes in vocanic activity do. See this chart I linked to earlier.

nor the cooling of Antarctica over the last 50 years,

See this article, especially:

A rise in the global mean temperature does not imply universal warming. Dynamical effects (changes in the winds and ocean circulation) can have just as large an impact, locally as the radiative forcing from greenhouse gases. The temperature change in any particular region will in fact be a combination of radiation-related changes (through greenhouse gases, aerosols, ozone and the like) and dynamical effects. Since the winds tend to only move heat from one place to another, their impact will tend to cancel out in the global mean.

nor the delayed reaction of greenhouse gases to climatic warmth seen in the ice cores.

Are you implying that current increases in greenhouse gases are not anthropogenic in origin?

 

[Shabaz]

What you're looking at are composites. The top one is the Siple Curve shifted 83 years to the Moana Loa CO2 meaurements so as to produce a single curve.

But no-one knows how the Siple curve was produced and how many readings above the "pre-industrial" 280ppm they erased to get the curve.

There is good evidence that ice cores are artificially deficient in carbon dioxide because of the properties of the ice the gases are found in. Other techniques such as from plant stomata, show that 6000 years ago, the CO2 concentration was ~350 ppm.

The modern value for carbon dioxide concentration is abnormally low in geological history. For long periods in the past, carbon dioxide levels were 10-20 times their current level, and were much higher even during million-years-long ice ages.

Anything to back up that datapoints were deleted, and known icecore characteristics that should be taken into account ignored? And in general, do you have anything that would show a better CO2 reconstruction than the ones used by the IPCC? Preferably something based on somewhat recent peer reviewed research, if at all possible. I'm looking through abstracts myself atm, but a pointer would be nice.

 

[Brian the Snail]

What you're looking at are composites. The top one is the Siple Curve shifted 83 years to the Moana Loa CO2 meaurements so as to produce a single curve.

How do you know it's the Siple curve, and not another ice core like the Law or Taylor domes? They all agree well with each other anyway.

There is good evidence that ice cores are artificially deficient in carbon dioxide because of the properties of the ice the gases are found in.

Link to the evidence then.

Other techniques such as from plant stomata, show that 6000 years ago, the CO2 concentration was ~350 ppm.

Some details on the stomata measurements here. How do you know that the stomata are specifically reacting to CO2 concentration, and not another factor? How do you account for the large and rapid fluctuations in the stomata data that don't appear in the modern instrumental measurements?

 

[Brian the Snail]

The modern value for carbon dioxide concentration is abnormally low in geological history. For long periods in the past, carbon dioxide levels were 10-20 times their current level, and were much higher even during million-years-long ice ages.

What was the Sun's luminosity during these ice ages, compared to today?

 

[Shabaz]

How do you know it's the Siple curve, and not another ice core like the Law or Taylor domes?

Ok, I hate to admit that I downloaded one of the AR4 WG1 reports that are still under embargo floating out there (especially considering the place I got it from), but I looked up what it used.

From right to left:
red line: NOAA/CMDL Global (Conway, 2004)
violet line: Mauna Loa (Kheeling and Whorf)
dark blue datapoints: Kohnen Station (Siegenthaler et al., 2004)
light blue datapoints: Southpole (Siegenthaler et al., 2004)
green datapoints: Law Dome (Etheridge et al.; MacFarling Meure)
purple datapoints: Dome C (Monnin et al., 2004)

Does that help any? And are there any significant criticisms in peer reviewed publications on any of the studies cited?

 

[Diamond]

There is no such thing as "proof" in Science.

Thanks. I'll now quote that freely.

No, but sulphate aerosols and changes in vocanic activity do. See this chart I linked to earlier.

There's no such thing as proof in Science. What you've quoted is the attributions given by climate modellers, who pick and choose which results they think are significant and which ones are flawed. It ain't science.

See this article,

Ignoring the fact that this comes from the Hockey Team, its a handwaving argument to excuse the plain fact that their greenhouse theory doesn't produce the polar amplification in the polar regions that the theory says it should.

Are you implying that current increases in greenhouse gases are not anthropogenic in origin?

Correct. In the ice cores, the rises in carbon dioxide and methane follow temperature rise between eight and ten centuries later. Eight to ten centuries ago we had the Medieval Warm Period, when temperatures globally in the high Arctic were higher than they are today. We would expect a rise in carbon dioxide as a delayed reaction to a warming.

The rise in carbon dioxide undoubtedly has an anthropogenic input. But to ignore the other 97% of carbon dioxide flux of natural origin is to make an error of attribution.

Also since we are on the subject of skepticism, it is also a rule of skepticism that correlation does not necessarily mean causation. The rise in carbon dioxide from 1958 onwards does not correlate with temperature until temperatures began to rise in the late 70s, so we have a handwaving argument to sulphates and particulates that are ad hoc parameters in climate models, not real world measurements. Nor is the fact that temperatures began to rise in the early 17th Century, well before carbon dioxide was supposed to be pouring from the Industrial Revolution, ever mentioned.

 

[Diamond]

What was the Sun's luminosity during these ice ages, compared to today?

I've no idea. I do know that if carbon dioxide was this dread heat-trapping gas that we are told it is, we would expect temperature rise to follow carbon dioxide rise - but it never has.

Over geological time, there appears to be little correlation between temperature and carbon dioxide concentration, and certainly no evidence of "enhanced greenhouse effects" in the past.

The greatest error is to assume that climate will not change all on its own. To attribute the tiny movement of a statistical composite like "global mean temperature" wholly to a single cause is simply ridiculous. The climate may warm and cool for no reason at all because its a non-linear system.

 

[Brian the Snail]

There's no such thing as proof in Science. What you've quoted is the attributions given by climate modellers, who pick and choose which results they think are significant and which ones are flawed. It ain't science.

Evidence?

Ignoring the fact that this comes from the Hockey Team, its a handwaving argument to excuse the plain fact that their greenhouse theory doesn't produce the polar amplification in the polar regions that the theory says it should.

Why precisely is it a handwaving argument? Polar amplification applies mainly to the artic, as explained in the article, and also here.

Are you implying that current increases in greenhouse gases are not anthropogenic in origin?

Correct. In the ice cores, the rises in carbon dioxide and methane follow temperature rise between eight and ten centuries later. Eight to ten centuries ago we had the Medieval Warm Period, when temperatures globally in the high Arctic were higher than they are today. We would expect a rise in carbon dioxide as a delayed reaction to a warming.

The rise in carbon dioxide undoubtedly has an anthropogenic input. But to ignore the other 97% of carbon dioxide flux of natural origin is to make an error of attribution.

The natural sources of CO2 aren't ignored, it's just that they're balanced by the natural sinks that absorb CO2. The amount of CO2 emitted by humans can be calculated, and the increase in CO2 in the atmosphere is measured, and the former exceeds the latter. So nature must be acting as a net sink, in that it is absorbing more than its emitting. How then, can natural sources be responsible for the increase?

More details here.

 

[bobdroege7]

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.

The story CapelDodger tells is that 380 PPM is unprecidented; that humans have pushed the atmosphere into new and dangerous territory. The facts are different. This isnt "uncharted territory" as he puts it. This is infact charted territory.

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.



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

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?

from

http://www.sciencentral.com/articles/view.php3?type=article&article_id=218392891

quote
"One is that the levels of CO2 that ultimately melted the ice sheets topped 1000 parts per million. That's the level that scientists agree we'll hit by the end of the century if we continue to burn fossil fuels at our current pace. "Now, 380 parts per million where we are today, is still nothing in comparison to levels of 1000 parts per million," she says."
endquote

At that level the article states that the earth was free of ice caps.

But I have not been able to find evidence for 500,000 ppm CO2

thanks

 

[Shabaz]

Diamond, do you have any studies I can read (again, preferably from peer reviewed publications if at all possible) that support any of these (what seem to me) big claims you seem to make?

-That climate modelers' handling or understanding of forcings is so flawed they really "pick and choose" on just what they think
-That the current increase in CO2 can be better attributed to a delayed response from 8-10 centuries ago than to an anthropogenic cause
-That there is something so fundamentally flawed with attribution studies for the warming trend in the global mean temperature, that it can be dismissed as "simply ridiculous"

I'm sure others will address the rest of your points, but these seem pretty significant things to say. A few months ago I spend a few weeks reading up on what I could find on climate science, and from what I have been able to read a lot needs to be wrong for you to be right. Please, tell me, what am I missing here?

 

[Brian the Snail]

I've no idea.

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 do know that if carbon dioxide was this dread heat-trapping gas that we are told it is, we would expect temperature rise to follow carbon dioxide rise - but it never has.

Never? Evidence?

Over geological time, there appears to be little correlation between temperature and carbon dioxide concentration, and certainly no evidence of "enhanced greenhouse effects" in the past.

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

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

The greatest error is to assume that climate will not change all on its own. To attribute the tiny movement of a statistical composite like "global mean temperature" wholly to a single cause is simply ridiculous. The climate may warm and cool for no reason at all because its a non-linear system.

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?

 

[Brian the Snail]

Ok, I hate to admit that I downloaded one of the AR4 WG1 reports that are still under embargo floating out there (especially considering the place I got it from), but I looked up what it used.

From right to left:
red line: NOAA/CMDL Global (Conway, 2004)
violet line: Mauna Loa (Kheeling and Whorf)
dark blue datapoints: Kohnen Station (Siegenthaler et al., 2004)
light blue datapoints: Southpole (Siegenthaler et al., 2004)
green datapoints: Law Dome (Etheridge et al.; MacFarling Meure)
purple datapoints: Dome C (Monnin et al., 2004)

Does that help any? And are there any significant criticisms in peer reviewed publications on any of the studies cited?

Thanks. It doesn't look like the Siple data is there at all. Isn't surprising, really, since it is quite old (mid 80's). By the way, the "shift" that Diamond refered to is briefly explained here.

At shallow depths, atmospheric air still circulates through the open pores (Friedli et al. 1986). The enclosed air was younger than the surrounding ice because the enclosure of air in bubbles occurred only between depths of 64 and 76 m. On the basis of porosity measurements, investigators determined that the time lag between the mean age of the gas and the age of the ice was 95 years and that the duration of the close-off process was 22 years (Schwander and Stauffer 1984).

 

[a_unique_person]

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?

What a lot of people don't seem to understand. The dispersion of the energy in the atmosphere is very difficult to predict. That overall, it has to come from and go somewhere is not that hard to fathom. Hence the term 'forcings'.

 

[DeviousB]

And to post the relevant chart from the last IPCC Fourth Assessment Report Summary to back Brian's statement up (I think this is the relevant chart, someone correct me if I'm wrong):

That graph only includes the anthropogenic factors (which is why water vapour is omitted), and displays only forcings (i.e. doesn't say anything about feedbacks).

From memory, about 2 pages before this graph there is a paragraph which states that the identified anthropogenic forcings are about +2.4 W/m², while changes in solar activity contribute about +0.12 W/m².

 

[DeviousB]

Ok, I hate to admit that I downloaded one of the AR4 WG1 reports that are still under embargo floating out there (especially considering the place I got it from), but I looked up what it used.

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

 

[shanek]

Thanks for the info about the sun.

Water vapour is classed as a "feedback", not a forcing, since its concentration responds to changes in temperature, which in turn drives further temperature increases.

But then, is CO2 not a feedback as well?

Let me tell you where I'm thinking with the water vapor thing:

A lot of environmentalists are touting the hydrogen cars as a solution to GW. They boast that the only exhaust is water vapor. Ignoring for the sake of the argument the energy you have to use to make the hydrogen, if a whole lot of people suddenly drove hydrogen cars, wouldn't it put more water vapor into the air and still contribute to GW?

This article explains it in more detail.

Thanks. Questions (of course):

He talks about "he relatively short residence time for water in the atmosphere (around 10 days)." He then talks about an experiment involving removing the water from the atmosphere and seeing how long the oceans take to replace it. Isn't this the exact opposite of what he was saying? He was saying that additional water vapor put into the atmosphere wouldn't stay there. His experiment didn't involve that.

Also, with the hydrogen car example, people will be driving these every day and putting more water vapor in the atmosphere, so if the water vapor is short-lived it hardly matters as they'll just be putting even more in as they drive anyway.

Also, if water will always obtain some sort of equilibrium in the atmosphere, then how can it be said to be a feedback? A feedback, I would think, would mean that additional water vapor would raise the global temperature, causing more water vapor to be put into the atmosphere, etc.

He says that this equilibrium is a result of the models. Has it been confirmed through observation or experimentation?

Volcanoes do emit CO2 as well as aerosols, but the aerosols more than counteract the CO2, leading to a net cooling for a few years after an eruption.

Yes, and the article you linked to touches on that. Thanks again.

 

[Diamond]

Evidence?

Yes. Quite.

Why precisely is it a handwaving argument? Polar amplification applies mainly to the artic, as explained in the article, and also here.

Explained where? Where is the evidence that polar amplification is happening at all even in the Arctic?

Polyakov et al (2004) addressed this very issue and found no polar amplification in the Arctic. And Antarctica continues to cool.

The natural sources of CO2 aren't ignored, it's just that they're balanced by the natural sinks that absorb CO2. The amount of CO2 emitted by humans can be calculated, and the increase in CO2 in the atmosphere is measured, and the former exceeds the latter. So nature must be acting as a net sink, in that it is absorbing more than its emitting. How then, can natural sources be responsible for the increase?

More details here.

Evidence that there is such a balance? If the natural sources and sinks are in such a balance, why does carbon dioxide vary at all?

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...

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?

 

[Diamond]

Thanks. It doesn't look like the Siple data is there at all. Isn't surprising, really, since it is quite old (mid 80's). By the way, the "shift" that Diamond refered to is briefly explained here.

And the gap is waved away. As Eric Morecambe used to say "You can't see the join!"