Is the Faint Young Sun Problem Solved by Increased Greenhouse Gases?

[Wax]

I'm just wondering if Global Warming is considered a fact within the science community? I'm not talking about man made global warming, just global warming in general whether it be caused by nature or man.

 

[Xnn]

Yes; it's a fact.

Global surface temperatures are rising as is the
temperature of the Oceans to several hundred meters while
there is an overall melting of ice and permafrost.

Sea levels are rising (actually accelerating) as expected primarily
from the thermal expansion with a contribution from melting ice.

The global average surface temperature has
increased, especially since about 1950. The updated
100-year trend (1906–2005) of 0.74°C ± 0.18°C

The world ocean has warmed since 1955, accounting
over this period for more than 80% of the changes in
the energy content of the Earth’s climate system.

Over the 1961 to 2003 period, the average rate
of global mean sea level rise is estimated from tide
gauge data to be 1.8 ± 0.5 mm yr–1.

There is high confidence that
the rate of sea level rise accelerated
between the mid-19th and the
mid-20th centuries based upon tide
gauge and geological data.

During the 20th century, glaciers and ice caps
have experienced widespread mass losses and have
contributed to sea level rise.

The Greenland and Antarctic Ice Sheets taken
together have very likely contributed to the sea level rise
of the past decade. It is very likely that the Greenland
Ice Sheet shrunk from 1993 to 2003, with thickening in
central regions more than offset by increased melting
in coastal regions. Whether the ice sheets have been
growing or shrinking over time scales of longer than a
decade is not well established from observations.

Temperature increases at the top of the permafrost layer of up to 3°C
since the 1980s have been reported. Permafrost warming
has also been observed with variable magnitude in the
Canadian Arctic, Siberia, the Tibetan Plateau and Europe.
The permafrost base is thawing at a rate ranging from
0.04 m yr–1 in Alaska to 0.02 m yr–1 on the Tibetan Plateau.

http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-ts.pdf

Notice that most of the heat of global warming is going into
the oceans. Only about 2% of the heat is going into surface temperatures.
See Figure TS.15 of the above link for a breakdown.

Also, the following reports month by month surface measurements.

http://www.ncdc.noaa.gov/oa/climate/research/anomalies/index.html

 

[MrGamma]

That is very interesting that most of the heat goes into the oceans. Is that due to the ice melting and perhaps warming the ocean, or is an indication that the warming is coming from other sources, such as the surface or the sea floor? I have always read that water absorbs more CO2 when it is colder, and as it warms it releases the CO2. (I have no practical experience doing so) Perhaps the sea water is absorbing the CO2 instead and thus heating the oceans?

That is incredibly interesting about the Mt.Pinatubo Volcanic Eruptions actually cooling the planet. I have always read that it had the opposite effect and that it was entirely negligible. Perhaps it is? What effect do hydro thermal vents, and underwater eruptions have on the effect of the oceans "salinity".

In particular, what is required to starve an ocean of oxygen? Will more Carbon Dioxide in water reduce it's ability to retain oxygen?

 

[Naty1]

Yes...but that doesn't mean much! During the 1970's the consensus was that an new ice age was "imminent" and was featured,for example, on the cover of Time magazine. (around 1974 or 1975).

It is far more accurate to say that the Earth undegoes warming and cooling cycles due to a wide variety of factors; ice ages, mini ice ages and warming periods are all part of the natural cycle and not fully understood.

 

[BCO]

Yes...but that doesn't mean much! During the 1970's the consensus was that an new ice age was "imminent" and was featured,for example, on the cover of Time magazine. (around 1974 or 1975).

It is far more accurate to say that the Earth undegoes warming and cooling cycles due to a wide variety of factors; ice ages, mini ice ages and warming periods are all part of the natural cycle and not fully understood.

 

[seycyrus]

I don't think that global cooling was ever a "consensus" view in the 70s. This is a very common piece of denialist FUD that gets tossed around all over the Web

Certainly there was no IPCC in 1970 that "declared" a consensus as the current IPCC "declared" one.

There certainly was a lot of talk in the 70s about cooling. Were you alive back then?

 

[Xnn]

Because the oceans are thousands of feet deep, they have a much larger heat capacity than the atmosphere. So, the oceans have been absorbing the bulk of the heat over the years. It's only because they are so large that they have been absorbing most of the heat.

The fact that sea levels are rising from thermal expansion and that overall ice is melting are independent confirmations that the globe is warming. There are also plenty of studies showing that the range of plants and animals are responding to climate change and climate zones shift poleward, so I don't see how anybody can reasonably dispute that there is warming going on.

Anyhow concerning the 1970's, my impression is that there were some people who noticed that a few years were cooler than some previous years and started wondering if perhaps there might be global cooling. The idea was discussed, but never got very far.

However, there are some similarities to today. Some people exclaim that 2005 or 1998 were very warm years and wonder if maybe the warming role of CO2 might be over stated since last year wasn't a record warm year. However, that is short sighted and counter to the consensus science of greenhouse gases.

Never the less, it's obvious that some people are extremely opposed to the whole idea of global warming, but it's not a legitimate scientific objection. Rather it seems more political. That they broke into computers shows me that honesty and integrity mean very little to them. They seem to be trying to make mountains out of mole hills in a fundamentally dishonest type of way.

 

[MrGamma]

OKay, UNderstood. There are three camps? Pro Human Global Warming and Pro Climate Change, and Pro No change.

I am fairly certain we are living on a dynamic planet. I have no doubts about this.

What concerns me are articles like this.

http://www.unep.org/geo/yearbook/yb2009/
What would cause the oceans to deplete of oxygen? Would more carbon dioxide added into water prevent it's ability to retain oxygen?

To my understanding, there are prehistoric records of oxygen deprived oceans existing throughout the geological record and some even claim that it is cyclical. (I am not sold on the concept 100% at the moment)

I am also not sold on the concept that the "dead zones" are caused only by fertilizers. What could have possibly caused it throughout the geological record? Maybe volcanic sulfur? Are volcanoes primarily spitting out Nitrogen in any regards?

However, from a chemical perspective. What causes water to lose it's ability to retain Oxygen. And is there anything in physics which would cause ocean water to absorb more heat than usual, perhaps additional CO2 would cause it to heat up? Or perhaps the release of CO2 would cause it to heat up?

Because the oceans are thousands of feet deep, they have a much larger heat capacity than the atmosphere. So, the oceans have been absorbing the bulk of the heat over the years. It's only because they are so large that they have been absorbing most of the heat.

This is something I have trouble understanding. Shouldn't there be a latentcy between the time the surrounding air heats up the oceans due to greenhouse gases?

If I put a glass of cold water in a room filled with hot air, the water takes it's time absorbing that heat, and it never rises beyond room temperature. Not to my knowledge anyways. Would more CO2 or nitrogen in the Oceans cause it soak up the heat in the atmosphere morseo that the surrounding "air"? Or is the sunlight penetrating more deeply with more force and more heat into the oceans?

What really freaks me out, is that whenever I search for things about underwater volcanoes off the gulf of mexico, that instantly, anti-human-global warming websites pop up. I am obviously not the only one who is questioning it.

 

[Xnn]

What would cause the oceans to deplete of oxygen? Would more carbon dioxide added into water prevent it's ability to retain oxygen?

Going OT here, but the Black Sea is a huge natural dead zone.
It is caused by the bottom water being isolated from mixing with the surface.
Whenever the bottom waters are isolated from the surface there
will be a dead zone since oxygen comes from the surface.
Of course, there are other causes too.

Shouldn't there be a latentcy between the time the surrounding air heats up the oceans due to greenhouse gases?

If I put a glass of cold water in a room filled with hot air, the water takes it's time absorbing that heat, and it never rises beyond room temperature. Not to my knowledge anyways. Would more CO2 or nitrogen in the Oceans cause it soak up the heat in the atmosphere morseo that the surrounding "air"? Or is the sunlight penetrating more deeply with more force and more heat into the oceans?

What really freaks me out, is that whenever I search for things about underwater volcanoes off the gulf of mexico, that instantly, anti-human-global warming websites pop up. I am obviously not the only one who is questioning it.

It does take time for the oceans to warm. However, the oceans have something like a hundred times the mass of the atmosphere. So, if they both warm up by the same delta temperature, then the oceans will have absorbed a hundred times the amount of heat.

An equal rise in temperature does not mean an equal amount of heat energy.
What is more massive (assuming similar specific heat capacity) will absorb more heat.

 

[MrGamma]

Sorry I didn't mean to go off topic. I am just trying to understand the science through the politics.

Going OT here, but the Black Sea is a huge natural dead zone.
It is caused by the bottom water being isolated from mixing with the surface.

So a dead zone can be accomplished through poor circulation and nitrogen (according to msn.com)

It does take time for the oceans to warm. However, the oceans have something like a hundred times the mass of the atmosphere. So, if they both warm up by the same delta temperature, then the oceans will have absorbed a hundred times the amount of heat.

Still not understanding this. But I do understand the temperatures taken in the above refer mostly to the first 700 meters in depth. What about the rest?

I will be honest... I am not 100% certain that human influence is the prime suspect in climate change.

I am more inclined to believe that it's simply a natural phenomenon. Probably to do with the volcanoes, hydro thermal vents, and rift systems which pour lava into the ocean continually. To my knowledge, however, this is also one of the least researched areas of the earth. So I guess perhaps it's easy to "guess" it might be responsible for it.

Shouldn't the sea temperature be cooling if massive ice sheets are melting into the oceans?

 

[Evo]

Still not understanding this. But I do understand the temperatures taken in the above refer mostly to the first 700 meters in depth. What about the rest?

No, actually SST (sea surface temperature) is only the first 1-2 meters of surface water.

A general definition of Sea Surface Temperature (SST) is the water temperature at 1-2 meters below the sea surface

http://www.csc.noaa.gov/products/gulfmex/html/datadesc.htm

 

[sylas]

I'm just wondering if Global Warming is considered a fact within the science community? I'm not talking about man made global warming, just global warming in general whether it be caused by nature or man.

Here's my proposal for a short summary statement on a huge question.

• It is a fact that Earth as a whole warms, or cools for a variety of reasons, and that it has done so throughout its long history.
• It is a fact that the Earth has recently (over the last century) warmed significantly.

There are different estimates for the amount of warming over the last century. They are invariably more than 0.5C and less then 1.0C, and tend to be around 0.7C in total, for the change in average global surface temperatures. The changes tend to be greater over the land than over the ocean and there are substantial regional differences.

Anything "fact" in science is still always open to question in principle. The two facts above are about as solid as science gets for measurements like this. There is of course on going work to get more refined measurements, and more accurate estimates of how warming distributes over time, and over Earth's surface. There is on-going research finding out about changes in the past, and quantifying how current changes compare in the rates of change and extent of change with other episodes of change in the past.

There are also other indicators of temperature than surface temperature which can be used. Surface temperature may be the easiest to measure in the present and also probably the most directly relevant for immediate impact.

Cheers -- sylas

 

[eachus]

Let me establish where I am coming from so you know how much salt to take with my posting. I grew up in Pennsylvania, where you often saw news about coal mines in the newspapers. The words were almost always followed by disaster, and preceded by another. Coal mining is dangerous. Also, go visit Scranton sometime and look at the miles and miles of piles of coal overburden covering what once was fertile farmland.

Whatever the effect of carbon dioxide on the weather, I worry about the effects on humans. We were not evolved as a species the last time carbon dioxide levels were this high. I'd gladly vote money to see if CO2 levels have anything to do with obesity, autism, or what have you. I'm pretty sure that there are some conditions of the elderly that are made worse by higher CO2 levels.

So for me, coal is very bad, and rising CO2 levels are worse. As for global warming? I'm not sure I am against it, even if it is caused by CO2 levels.

Back to the 1970s. You may not remember but there was a major global concern by pilots. The horizon was disappearing. This was considered by pilots to be a severe problem because they relied on the horizon to orient themselves while flying. The disappearing horizon was due to what we would call today nanoparticles of carbon and hydrocarbons suspended in the air, mostly from 707s and other commercial jets. The solution? It had already started. Turbofan (as opposed to turbojet) engines were much more efficient for passenger planes. In a turbofan some of the air taken in by the first fan stage bypasses the compressor and burners. It also results in complete combustion when the bypass air mixes with the air that passed through the compressor and turbine. Airlines all switched to turbofan engines for the fuel savings, and within a few years the horizon returned. I had to wonder if turbofans got extra thrust by burning up unburned particles left by turbojets. I would have expected them to take decades to fall out of the stratosphere.

Anyone who lived in the LA area I am sure remembers a similar phenomena, smog. Diesel engines tuned for maximum efficiency emitted similar particles, as did poorly tuned automobiles. I'm sure we could have had clean air in LA without catalytic converters on automobiles, as long as they got the diesel trucks--and required frequent emissions checks on automobiles. Oh, well. The catalytic converter for everyone approach worked, it just took a lot of research to design automobile engines that worked efficiently with them.

Where am I going with this? I think that given time, the CO2 problem will be corrected like the horizon problem. I can already see that cars five years from now will be at least twice as efficient as today's cars. In part because of worries about high fuel costs, in part due to the improvements in efficiency that come sort of for free when you use electricity instead of a drive shaft. Braking energy is recovered instead of wasted. Even if you have a gasoline engine, it can be tuned to be much more efficient if it runs at just one speed. What about fuel cells? They are coming, but not that fast. And the big thing to sort out is whether they will use hydrogen, methane, methanol, ethanol, or some other fuel. In reality eventually the real fuel is protons (hydrogen ions). The rest is about how you store them, and get them into the fuel cell.

My guess? Methanol, or a methanol/ethanol mix will win out. It is compatible with current delivery systems and also with driver's expectations. The fact that methanol is a much less dangerous fuel in a crash is just a nice side benefit. But all that will take place whether or not a treaty to replace Kyoto is ever signed. It is progress, it is more efficient, and thus saves money. Saving the planet is nice, but doing it at a profit is nicer.

As for base load electrical power, the sooner politicians bite the bulllet and start approving nuclear power plants again, that problem will go away. I could write a whole article on the improvements in nuclear power plant designs and safety, but I won't do that here. The base load problem won't go away. The possibilities are wait until fossil fuel prices go through the roof, build nuclear plants now, or hope for a miracle.

Huh? Green renewable power is nice. It can also potentially provide a lot of swing power, and if done without subsidy, at a sensible price, it won't bust the federal budget. What it can't do is provide reliable power when a blizzard hits the northeast in January. Even if there are lots of wind turbines. ;-) A certain fraction of the electric power generating capacity needs to be reliable in all kinds of weather, and wind and solar are not.

There may be some technology out there that can eventually replace nuclear power without burning coal. But it won't have much of an effect on US or European or Chinese power generation before 2020. And we need to start building new generating plants now, not next decade, or the decade after. We also need to get the Chinese to stop building one new coal plant a week, and do it by example, not by raising the price of coal. (Although that might work. ;-)

 

[russ_watters]

Because the oceans are thousands of feet deep, they have a much larger heat capacity than the atmosphere. So, the oceans have been absorbing the bulk of the heat over the years. It's only because they are so large that they have been absorbing most of the heat.

To quantify that, the mass of a column of air the height of the atmosphere is equal to the mass of a column of water about 10m deep. Since the oceans are about 65% (?) of the surface area of the earth, once you've gone down 15m, you're already dealing with more mass of water than there is air in the atmosphere.

 

[atyy]

An ad-hoc committee of the American Physical Society recently reviewed the that Society's 2007 Statement on Climate Change. The committee's report reads in part:

"There are a number of problems with this statement. The first sentence presents as a fact what is only a surmise. Although the evidence is strong that climate warming has anthropogenic sources, as described above, anthropogenic warming is not a proven fact. Consequently, the wording in the first sentence “are changing the atmosphere” should have been “are probably changing the atmosphere”. In the second paragraph, the first sentence states that the fact of climate warming is incontrovertible, which is true. However, by its context this is easily misread to mean that anthropogenic warming is incontrovertible. The only clue that there are uncertainties in the predictions for the global climate is the phrase “likely to occur” in the second paragraph. This hardly conveys the great uncertainties in analysis displayed in PSB. The paragraph as a whole has an alarmist tone that belies the underlying uncertainties. ...

Despite the uncertainties in detailed predictions, it is the conviction of this committee that the APS would be well advised not to retract its support for policies and actions that are aimed at reduction in the production of greenhouse gasses. The weight of the evidence we have examined points to this as a prudent policy position."

 

[Bored Wombat]

I will be honest... I am not 100% certain that human influence is the prime suspect in climate change.

Well, in terms of the scientific literature, it is the prime suspect for climate change since the middle of last century.

On other time scales there are other prime suspects. The glaciation and interglacial cycles of the last million years and perhaps two are suspected to be primarily from Milankovitch cycles, by a physical mechanism that is not understood. Certainly CO2 provides an important feedback, but does not explain most of the temperature change from the top of an interglacial to the bottom of an ice age.

Specifically the 170 to 270 ppm variation of CO2 should make about 2°C of the about 10°C temperature change.

The bulk of it, AFAIK is ice-albedo feedback.

I am more inclined to believe that it's simply a natural phenomenon. Probably to do with the volcanoes, hydro thermal vents, and rift systems which pour lava into the ocean continually. To my knowledge, however, this is also one of the least researched areas of the earth. So I guess perhaps it's easy to "guess" it might be responsible for it.

Volcanic forcing (being aerosol forcing) is well considered. Geothermal heat is understood to be a negligible source of heat to the atmosphere and ocean. It's pretty much all the sun.

Shouldn't the sea temperature be cooling if massive ice sheets are melting into the oceans?

The last time I did the figures, the radiative imbalance due to the enhanced greenhouse effect is more than the latent heat of fusion of the melting sea ice.

 

[ZacharyFino]

its weird, when i was younger i always thought that the planet was getting warmer and warmer because its covered in billions of buildings all using electricity and cars people etc. so much going on on the surface it just seems if you isolate it as a system there is a large amount of energy wrapped around the planet, then in the 9th grade global warming by CO2 gasses was introduced to me. I've been skeptical the whole time, i accept the physics of greenhouse gases but it doesn't seem apparent to me that the greatest source of global warming is CO2 and that it is an immediate problem.

 

[andrewBR]

I don't guess that the global warming is a fact!
Tha planet is very strange, but this the result of the millions years of evollution
For me, this is normal, the planet needs change!

 

[sylas]

its weird, when i was younger i always thought that the planet was getting warmer and warmer because its covered in billions of buildings all using electricity and cars people etc. so much going on on the surface it just seems if you isolate it as a system there is a large amount of energy wrapped around the planet, then in the 9th grade global warming by CO2 gasses was introduced to me. I've been skeptical the whole time, i accept the physics of greenhouse gases but it doesn't seem apparent to me that the greatest source of global warming is CO2 and that it is an immediate problem.

The original source of warming for the Earth is the Sun. Nothing else even comes close to making the slightest difference as an energy source. All climate impacts come from changing in some way the flow of energy that comes from the Sun.

The Sun itself is remarkably constant; but the way that energy flows through the Earth is not. Earth radiates all the energy it receives from the Sun. This is called "energy balance". There can be a short term imbalance with energy actually being stored or released from the Earth, but this cannot last. The amount of energy is too large.

What makes a difference for temperature is basically two things.

• Albedo. How much solar energy gets reflected. Reflected energy does not contribute to heating.
• Emissivity. This is a measure of how efficient the Earth is at radiating heat. This is where carbon dioxide makes a difference. It makes it a bit harder for the thermal energy radiated from the Earth to get out into space; and that means you end up with higher temperatures just to keep radiating the same amount of energy.

To accept the physics of greenhouse gases MEANS to recognize a strong effect on temperature from just this effect. The physics involved implies higher temperatures when you have more greenhouse gases.

Cheers -- sylas

 

[eachus]

To accept the physics of greenhouse gases MEANS to recognize a strong effect on temperature from just this effect. The physics involved implies higher temperatures when you have more greenhouse gases.

Yep, the physics is easy--if you have growing levels of greenhouse gases (GHG) in the atmosphere. However, the primary GHG is water vapor. If the amount of water vapor was constant, then it would be easy to make working models of the atmosphere that include radiative forcing from CO2. But it is not that simple by any means. Clouds increase albedo, and thus reflect more sunlight, but they also trap heat, preventing radiative cooling from the ground or ocean under the clouds. So do clouds cause warming or cooling? Both, and sometimes at the same time. :-(

Remember that I am in favor of reducing CO2 levels. I just don't think that radiative forcing from CO2 is real.

There is not much research money these days for studying the Gaia hypothesis, that natural feedback paths make Earth's climate self regulating. But given that the solar constant has not been constant when looked at over billion year timescales, something has kept Earth from being an iceball or a Venus-like hothouse.

To be perfectly fair, current research seems to indicate that the Earth did go through an iceball (or slushball) phase several times over half a billion years ago. But it didn't stay locked in that mode. There are scientists trying to fit models that make CO2 responsible for leaving the icehouse mode. I happen to favor mountain building as the solution. And the long north-south mountain chain along the Pacific edge of the Americas as why the recent (in geological terms) Ice Ages didn't become Iceball Ages.

 

[sylas]

Remember that I am in favor of reducing CO2 levels. I just don't think that radiative forcing from CO2 is real.

My primary interest in this is from a long time interest in science education and issues where science gets misunderstood in the public sphere. What we ought to do policy wise is a social issue, which is best informed after we understand the best available relevant science.

The radiative forcing of CO₂ is one of the simplest and most elementary aspects of the whole science of climate. The physics of it has been known since the nineteenth century, and it can be quantified quite accurately with calculations from a couple of decades ago. (The full calculation is pretty arduous and requires a lot of computer time to integrate over the vertical atmosphere profile and over the electromagnetic spectrum.)

The result is 5.35 W/m² of forcing per natural log of CO₂, accurate to 10% or so. The major reference for this is

• Myhre et al., (1998) http://www.agu.org/pubs/crossref/1998/98GL01908.shtml, Geophysical Research Letters, Vol 25, No. 14, pp 2715-2718.

Note that the forcing is not in terms of temperature, but energy flux. This is what forcing means.

The next obvious question, of course, is what consequences the additional energy flux has for temperature. It will increase temperature of course; but how much? This is the source of the real uncertainties and open questions in climate science; the complex nature of the Earth response.

As temperatures rise, you get increasing specific humidity, and this (as you point out!) is the major greenhouse gas on Earth. This increase in humidity is measured, and it works as a strong positive feedback, basically amplifying the response to ANY forcing.

The other major effect is changes to weather patterns, and cloud in particular. This (as you point out) is very complicated. Most research indicates that the net effect of changing cloud in a situation of increasing temperatures is another positive feedback; although its magnitude is one of the greatest sources of uncertainty and even its sign is subject to question; under certain conditions it will be a negative (moderating) feedback.

There is not much research money these days for studying the Gaia hypothesis, that natural feedback paths make Earth's climate self regulating. But given that the solar constant has not been constant when looked at over billion year timescales, something has kept Earth from being an iceball or a Venus-like hothouse.

You don't need a Gaia hypothesis for that, or self-regulation. Even with mostly positive (amplifying) feedbacks you tend to get reasonable long term stability. There's been a lot of very significant climate change over that period. For example: consider the cycle of ice ages over the last 2.8 million years (Quaternary period). Those are very large climate shifts, and they are driven by very small changes in Earth's orbit, we think. That requires some strong positive amplifying feedbacks to give such large swings in climate.

The only reason the swings don't go to a slushball or to a Venus like hothouse is that the feedbacks are still subcritical, so the response to a bounded forcing is itself bounded. Trying to marry that with the idea of "self-regulation" is rather odd.

Be that as it may, there's plenty of scope for looking at longer term feedback processes.

To be perfectly fair, current research seems to indicate that the Earth did go through an iceball (or slushball) phase several times over half a billion years ago. But it didn't stay locked in that mode. There are scientists trying to fit models that make CO2 responsible for leaving the icehouse mode. I happen to favor mountain building as the solution. And the long north-south mountain chain along the Pacific edge of the Americas as why the recent (in geological terms) Ice Ages didn't become Iceball Ages.

That is a very strange idea. You don't need any particular "reason" why recent Ice Ages don't go to slush balls. The only way to get the extreme slush ball is a runaway positive feedback. You don't need anything special to prevent this; and in particular you could probably have the Americas flat as a pancake without causing slushballs from the small forcings involved in the ice ages.

Ironically, the major effects of Earth's current arrangement of continents is to reduce the stability of climate, and contribute to the case where we've been having these large swings in climate in and out of Ice Ages with what are comparatively small orbital forcings. That is, these are not moderating influences; but actively help bring about large climate swings.

See, for example, Shifting Continents and Climates, a background article at Oceanus (23 Feb 2004) at the Woods Hole Oceanographic Institute.

Cheers -- sylas

 

[ViewsofMars]

Hi :)

I used to live on an island, and it was there I fell in love with the whales, dolphins and porpoises. I don’t want them to suffer. I’m especially fond of dolphins because they are super intelligent and playful creatures. I found this article which made me sad.

The Impact of a Changing Climate on Whales, Dolphins and Porpoises by Wendy Elliott, WWF Global Species Programme, and edited by Mark Simmonds, Whale and Dolphin Conservation Society (WDCS).

http://www.wdcs.org/submissions_bin/whales_hot_water.pdf

On a happier note, a friend of mine gave me a present. It was a huge gourd that had small (three inch) strokes of blue and white little whales on it and was painted by a killer whale. I have a photograph of the whale painting the gourd! It's awesome. Everytime I look at it I think of the beauty that is alive and breathing, which brings me joy. There was a "Certificate of Authenticity" that came along with the gourd. It reads, "Shouka, Killer Whale (Orcinus orca) is one of Six Flags Discovery Kingdom's most enthusiastic painters. Painting is one of the many fun activities Shouka enjoys with her trainers between shows. She painted her first gourd in honor of the 2nd annual Mare Faire. She loves a lot of attention from her trainers, dolphin companions, and other human friends. She can often be heard outside Shouka Stadium when she is vocalizing with excitement during a variety of activities such as painting, mimicking her trainers and eating ice."

 

[eachus]

The radiative forcing of CO₂ is one of the simplest and most elementary aspects of the whole science of climate. The physics of it has been known since the nineteenth century, and it can be quantified quite accurately with calculations from a couple of decades ago. (The full calculation is pretty arduous and requires a lot of computer time to integrate over the vertical atmosphere profile and over the electromagnetic spectrum.)

The result is 5.35 W/m² of forcing per natural log of CO₂, accurate to 10% or so. The major reference for this is

• Myhre et al., (1998) http://www.agu.org/pubs/crossref/1998/98GL01908.shtml, Geophysical Research Letters, Vol 25, No. 14, pp 2715-2718.

Maybe I didn't spell it out well enough. So I'll let H. L. Mencken try: "For every complex problem, there is a solution that is simple, neat, and wrong." In this case the assumption that blows up is that the CO2 is evenly distributed throughout the atmosphere. We now know that assumption is wrong in two dimensions. CO2 is heavier than air, so anthropocentric CO2 tends to stay in the lower atmosphere, where it does not contribute to radiative forcing or global warming. (CO2 from volcanoes is injected into the upper atmosphere, and tends to stay there. But that is a different issue.)

The other simplifying assumption that fails is that anthropocentric CO2 is distributed evenly in latitude. NASA has some nice animations which show just how wrong this is--there are two belts of anthropocentric CO2 in the mid-latitudes in both hemispheres, while the CO2 concentration in higher latitudes and at the equator is much lower.

Put it all together, and anthropocentric CO2 doesn't do much forcing, if any. But remember what I said, that I am very much in favor of reducing CO2 emissions because the current levels are already killing people--but elderly people and people with asthma, not by global warming.

A good test of how well someone understands the issues is their attitude towards nuclear power. Nuclear power is the only remotely reasonable replacement for base load coal plants today. You are allowed to be opposed to liquid metal fast breeder reactors (LMFBRs) but that is a detail. I don't know of anyone who still wants to build LMFBRs to close the nuclear fuel cycle. Today, gas cooled and molten salt breeders are a much safer, and actually less expensive alternative.

 

[sylas]

Maybe I didn't spell it out well enough.

You spelt it out just fine. It is not that I fail to understand you; it is that we disagree. Put more bluntly; you are incorrect, and spelling it out in more detail only underlines the problems.

In this case the assumption that blows up is that the CO2 is evenly distributed throughout the atmosphere. We now know that assumption is wrong in two dimensions. CO2 is heavier than air, so anthropocentric CO2 tends to stay in the lower atmosphere, where it does not contribute to radiative forcing or global warming. (CO2 from volcanoes is injected into the upper atmosphere, and tends to stay there. But that is a different issue.)

Variation in CO₂ levels is not enough to make a significant difference to the forcing in different parts of the Earth. The extra weight is irrelevant; the various gases are well mixed in the troposphere and do not separate out by weight until you get above the tropopause. The global warming impact of greenhouse gases is due to their existence below the tropopause, because their crucial role is to leave the bulk of atmospheric thermal emissions from the tropospause, which is much colder than the surface.

A recent thread has been started on improved details in CO₂ measurements from the NASA AIRS project. See the thread [thread=363850]AIRS and Atmospheric Carbon Dioxide[/thread]. The measurements shown are for mid-troposphere, and the variation is only a few percent -- as expected for well mixed gases in the turbulent troposphere. The variation is far less that the steady increase occurring at all latitudes and all altitudes as atmospheric CO₂ levels continue to rise.

It is a requirement of this forum that controversial claims be backed up by suitable scientific references. In this case, your assertions about a separation of CO₂ by weight, and of a lack of any contribution to forcing for anthropogenic CO₂ is in conflict with very elementary atmospheric physics.

The other simplifying assumption that fails is that anthropocentric CO2 is distributed evenly in latitude. NASA has some nice animations which show just how wrong this is--there are two belts of anthropocentric CO2 in the mid-latitudes in both hemispheres, while the CO2 concentration in higher latitudes and at the equator is much lower.

By "much" you mean about 2%? Did you even read that research?

Put it all together, and anthropocentric CO2 doesn't do much forcing, if any. But remember what I said, that I am very much in favor of reducing CO2 emissions because the current levels are already killing people--but elderly people and people with asthma, not by global warming.

CO₂ levels are pretty much irrelevant for direct impact on health, at least at the levels seen in the normal atmosphere. The effect of atmospheric CO₂ on asthma is negligible. Again, you should support claims like this.

I have quoted the references for forcing of 5.35 W/m² per natural log CO₂. This is a well established forcing, not in any credible doubt. Your claims about variation in CO₂ levels don't appear to appreciate how small these variations actually are. Anthropgenic CO₂ mixes all through the atmosphere, and by basic thermodynamics it necessarily gives a substantial radiative forcing. The forcing due to CO₂ increases since pre-industrial times is about 1.7 W/m², corresponding to a rise from 280ppm to 385ppm, and the source of this increase is anthropogenic, as established by the Suess effect and also by simple bookkeeping with the magnitude of fluxes involved.

The impacts or social issues or policy issues are not on topic in this thread. The question is simply about getting the science of climate right. Is global warming a fact? Yes it is; and so also is the significance of CO₂ as a major contributing factor to increasing temperatures.

What remains uncertain is the magnitude of climate response to various forcings (sensitivity), the associated patterns of climate change as the globe heats up, and also the contribution of various other forcings, both non-greenhouse forcings, and greenhouse forcings from other gases.

Cheers -- sylas

 

[Xnn]

eachus;

Global warming due human emission of CO2 is a fact. However, the rate of change is so slow (0.02C/year) that it is difficult to measure and easy to dismiss. Even over 10 years, 0.2C is a small change.

On a typical day, temperatures vary by 10C between day and night.
While from one day to the next, 3 or 4 C is not unusual.

So, even though the science of global warming from CO2 is well understood and http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html" , we will continue to find people that are quick to reject it without taking the time to understand it.

Some of the opposition is due to a lack of knowledge, but others are driven by fear and political motives.

 

[Bill Illis]

Anyone ever put Myhre's forcing estimates into the Stefan-Boltzmann equations.

If the total forcing increase from GHGs is 1.7 W/m2, the Stefan-Boltzmann equations predict very little temperature change from an increase this small.

Surface TempK Today = (390 W/m2/5.67E-08)^.25 = 287.98K = 15.0C

Surface TempK Pre-Ind = (388.3 W/m2/5.67E-08)^.25 = 287.66K = 14.7C

So either Myhre's estimates are not really the traditional watts/metre^2 measure we use normally or the Stefan-Boltzmann equations aren't even being used.

 

[ViewsofMars]

The American Association for the Advancement of Science has the “Science Insider” with articles pertaining to this discussion. I think it’s worthy of a review. Thanks.

http://blogs.sciencemag.org/cgi-bin/mt/mt-search.cgi?tag=Copenhagen&blog_id=9&IncludeBlogs=9

 

[sylas]

Anyone ever put Myhre's forcing estimates into the Stefan-Boltzmann equations.

Yes, they have. What the Stefan-Bolzmann equations give you is called "non-feedback response". But note that the forcing calculation by Myhre is not based on Stefan-Bolztman. It is based on radiative transfers up and down a transparent atmosphere. The calculation you are doing is a kind of check to see how the known forcing of CO₂ matches up with the observed changes in temperature.

The difference with the real climate on Earth is that as temperature increases, so also do other aspects that bear upon energy balance. Ice melts (increasing albedo), humidity increases (more greenhouse, but less lapse rate) cloud changes (altering both greenhouse and albedo in complex ways); plus also changes in vegetation and land cover.

All this becomes feedback, either positive or negative, which bears upon "climate sensitivity" to either amplify or damp the base non-feedback response.

I mentioned this in my earlier post, as an aspect of climate that is NOT well known. The base non-feedback response is pretty well constrained, but it does not suffice to let you infer the temperature impact.

If the total forcing increase from GHGs is 1.7 W/m2, the Stefan-Boltzmann equations predict very little temperature change from an increase this small.

Surface TempK Today = (390 W/m2/5.67E-08)^.25 = 287.98K = 15.0C

Surface TempK Pre-Ind = (388.3 W/m2/5.67E-08)^.25 = 287.66K = 14.7C

So either Myhre's estimates are not really the traditional watts/metre^2 measure we use normally or the Stefan-Boltzmann equations aren't even being used.

There are several omissions in your application of Stefan-Boltzmann, even ignoring the effects of all the feedback processes. Most importantly, you are mixing up a surface temperature change with a forcing that is defined with respect to the top of the atmosphere.

Here is a better way of doing it. The Earth is not a black body emitter. You must consider both albedo and emissivity.

The Earth has an albedo of about 0.3, which means that about 30% of the solar input is reflected, and does not give any heating. Also, the radiation into space from the Earth corresponds to an effective temperature of about 255K. This is because of the greenhouse effect, which gives Earth an effective emissivity. Surface temperature is about 288K, because of the additional blanketing effect of the atmosphere.

You get into the right ball park by using a grey-body approximation relating surface temperature to the absorbed solar energy. For a grey-body, the Stephan-Boltzmann relation is

Q = \sigma \epsilon T^4​

Q is the thermal emission flux from the top of the atmosphere, and ε is an effective emissivity. T is the surface temperature.

The solar constant is about 343 W/m² over the surface of the planet. 30% of this is reflected, leaving 240 W/m² energy absorbed. This is what Earth emits as thermal radiation; it is the value for Q. T is the surface temperature, about 288K.

The value for ε is about 0.6; but in fact we can cancel it as follows.

\frac{dQ}{dT} = 4 \sigma \epsilon T^3 = 4Q/T​

The rate of change of energy emitted with temperature is about 4 * 240 / 288 = 3.3 W/m²/K. This is a non-feedback response. For every 3.3 W/m² of forcing (change in Q) we should get about a degree of temperature change -- ignoring feedbacks.

The 1.7 W/m² forcing corresponds to a bit over half a degree.

You obtain a slightly smaller value because you are using Stephan-Boltzmann at the surface, with Q=390 as the emission of radiation from the surface. But that's the wrong comparison for a forcing, which by definition is the change in energy balance at the top of the atmosphere. The method with a non-unit emissivity will give you a closer value for the proper application of Stefan-Boltzman to a forcing. There are in the literature more detailed calculations considering the emissivity of the atmosphere and the fact that the Earth is not a uniform sphere. The value obtained is around 3.2 W/m²/K; close to the simple approximation I used above.

There are a number of important provisos with this number.

• It ignores all feedbacks. This is one of the major open questions in climate research. Most of the available evidence indicates a net positive feedback, to give a substantial amplification of the base response. A small minority of researchers propose a zero or negative feedback, but over all they have not been made a good scientific case for this, and nearly all estimates suggest that the base response is increased by a factor of around 2 to 4 times.
• This is an equilibrium response. Since it takes a long time for the ocean to heat up in response to a new forcing, you don't get all this temperature increase realized at once. Research indicates at present a steady flux of energy flowing into the ocean. This represents a forcing that is not yet realized as a surface temperature increase.
• It ignores all other forcings; there's more than CO₂ involved.

As it turns out, these additional considerations mostly cancel out. The effect of time delay with heating of the ocean works in the short term rather like a negative feedback, and so the observed amplification short term is smaller than than full equilibrium response. The other additional forcings are both positive and negative, and of comparable magnitudes each way.

The net effect is that the base response is not that far off what we should experience; generally estimated to be a small amplification over base response.

So... a naive application of Stefan-Boltzman to CO₂ levels alone gives about half a degree of heating. And the actual temperature rise we have observed is in a similar ballpark... around 0.7 degrees.

For more discussion in other threads:

• Feedback is now being discussed in thread [thread=360877]The AGW climate feedback discussion[/thread].
• Base response is discussed, with references, in [post=2199572]msg #69[/post] of thread "Physics of Global Warming", and [post=2225918]msg #47[/post] of "Ocean heat storage". The values given for base response from the literature are about 3.2 W/m²/K.

Cheers -- sylas

 

[Xnn]

Bill; That's a good point.

Although I apply the Stefan-Boltzmann differantly, I still get a similar answer; 0.5C.

Basic Stefan-Boltzmann equation:

Temp (K) = [2*TSI*emissitivity*(1-albedo)/(4*5.67*x10^-8)]^(0.25)

TSI: Total Solar Irradiance - Watts/m^2
emissitivity; nominally 0.81 - unitless
albedo; nominally 0.3 - unitless

The 1.7 watt/m^2 forcing is applied to what could be considered to be the net incoming radiation term:

TSI*(1-albedo)/4

net result 0.5C of warming since pre-industrial times due to human influence and including solar changes.

The IPCC gives a global mean radiative forcing value since pre-industrial times of 1.6 watts/m2 with a range of 0.6 to 2.4. This includes all greenhouse gases, land use, black carbon, aerosols, contrails and solar irradiance.

What's missing are the feedbacks from water vapor and snow/ice melting albedo changes. So, feedbacks have made the observed warming greater than that from the underlying inital changes.

 

[Bill Illis]

I guess I have a number of issues with the standard explanations for the physics of global warming (and thanks to sylas and Xnn for indulging me here):

First, the Stefan-Boltzmann equations are the fundamental equations governing radiation physics and temperature. I really think that global warming theory needs to be consistent in some form with these proven and successful equations.

Second, the Stefan-Boltzmann equations are logarithmic. The surface of the Earth needs to add 5.5 W/m2 to go up by 1.0K but the Sun needs to add 50,000 W/m2 to increase its temperature by 1.0K. We can't use averages covering many different radiation levels in these calculations. It must be done on each individual extra watt, one at a time - the differential rather than the average.

Third, there are four different levels of the atmosphere which are emitting at 240 W/m2. Traditionally, the tropopause is defined as the level where the Earth is in equilibrium with the Solar forcing - the first level where that occurs is about 4 kms up - lower than the top of Mount Everest and lower than the definition of the tropopause.

http://www.fas.org/irp/imint/docs/rst/Sect14/FIG01_019.jpg

Fourth, all the effective action of the greenhouse effect operates below this 4 km level. We use the term "Emissivity or even the Lapse Rate" but isn't this really just the time delay it takes for an Infra-Red photon from the surface to random walk/bounce around the atmosphere and the surface before it reaches the 4 km level and eventually escapes back into space. The average time a photon from the Sun spends in the Earth system is only 18 hours (some make it to the deep ocean and spends a thousand years in the Earth system while the majority of the energy represented by photons from the Sun escapes to space overnight after bouncing around a million individual atmosphere molecules. For every 240 W/m2 coming in from the Sun, an extra 150 w/m2 is time-delayed/accumulated near the surface to provide the Greenhouse Effect and keep the surface 33K warmer than the equilibrium temperature at 4 kms high.

Fifth, since these issues are so complicated and prone to error, why do we not look at the empirical evidence of the paleoclimate to provide an independent verification of the theory. Since the issues are so theoritical, we should go back to ground and see what has really happened in the climate per doubling of CO2. The actual/estimated temperature and CO2 history of the climate does not verify the 3.0C per doubling estimate. The paleoclimate is only consistent with 1.0C to 1.5C per doubling.

Maybe I am way off base here, but these issues are not addressed in the standard explanation. It only takes a 25% error in the estimates from the standard explanation to make a huge difference in the global warming per doubling estimate.

 

[ViewsofMars]

I'm fond of the ocean as one can tell by a previous posting. As a responsible citizen of planet Earth, and a concerned one at that, it's important for me to learn about my environment and the options available. Foremost, I like to share with others so they are informed as well. :)

Comput Biol Chem. 2009 Dec;33(6):415-20. Epub 2009 Oct 2.

Modelling effects of geoengineering options in response to climate change and global warming: implications for coral reefs.
Crabbe MJ.

LIRANS Institute for Research in the Applied Natural Sciences, Faculty of Creative Arts, Technologies and Science, University of Bedfordshire, Park Square, Luton LU1 3JU, UK. james.crabbe@beds.ac.uk

Climate change will have serious effects on the planet and on its ecosystems. Currently, mitigation efforts are proving ineffectual in reducing anthropogenic CO2 emissions. Coral reefs are the most sensitive ecosystems on the planet to climate change, and here we review modelling a number of geoengineering options, and their potential influence on coral reefs. There are two categories of geoengineering, shortwave solar radiation management and longwave carbon dioxide removal. The first set of techniques only reduce some, but not all, effects of climate change, while possibly creating other problems. They also do not affect CO2 levels and therefore fail to address the wider effects of rising CO2, including ocean acidification, important for coral reefs. Solar radiation is important to coral growth and survival, and solar radiation management is not in general appropriate for this ecosystem. Longwave carbon dioxide removal techniques address the root cause of climate change, rising CO2 concentrations, they have relatively low uncertainties and risks. They are worthy of further research and potential implementation, particularly carbon capture and storage, biochar, and afforestation methods, alongside increased mitigation of atmospheric CO2 concentrations.

PMID: 19850527 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/sites/e...ez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

J Air Waste Manag Assoc. 2009 Oct;59(10):1194-211.

Global climate change and the mitigation challenge.
Princiotta F.

Air Pollution Prevention and Control Division, National Risk Management Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA. Princiotta.frank@epa.gov

Anthropogenic emissions of greenhouse gases, especially carbon dioxide (CO2), have led to increasing atmospheric concentrations, very likely the primary cause of the 0.8 degrees C warming the Earth has experienced since the Industrial Revolution. With industrial activity and population expected to increase for the rest of the century, large increases in greenhouse gas emissions are projected, with substantial global additional warming predicted. This paper examines forces driving CO2 emissions, a concise sector-by-sector summary of mitigation options, and research and development (R&D) priorities. To constrain warming to below approximately 2.5 degrees C in 2100, the recent annual 3% CO2 emission growth rate needs to transform rapidly to an annual decrease rate of from 1 to 3% for decades. Furthermore, the current generation of energy generation and end-use technologies are capable of achieving less than half of the emission reduction needed for such a major mitigation program. New technologies will have to be developed and deployed at a rapid rate, especially for the key power generation and transportation sectors. Current energy technology research, development, demonstration, and deployment (RDD&D) programs fall far short of what is required.

PMID: 19842327 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/sites/e...ez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

Title: The Arctic Ocean marine carbon cycle: evaluation of air-sea CO2 exchanges, ocean acidification impacts and potential feedbacks
Authors:
Bates, N. R.; Mathis, J. T.
Affiliation:
AA(Bermuda Institute of Ocean Sciences, Ferry Reach, Bermuda nick.bates@bios.edu), AB(School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA)
Publication:
Biogeosciences, Volume 6, Issue 11, 2009, pp.2433-2459 (COPERNICUS Homepage)
Publication Date:
11/2009
Origin:
COPERNICUS
Bibliographic Code:
2009BGeo...6.2433B

Abstract
At present, although seasonal sea-ice cover mitigates atmosphere-ocean gas exchange, the Arctic Ocean takes up carbon dioxide (CO2) on the order of ‑66 to ‑199 Tg C year‑1 (1012 g C), contributing 5–14% to the global balance of CO2 sinks and sources. Because of this, the Arctic Ocean has an important influence on the global carbon cycle, with the marine carbon cycle and atmosphere-ocean CO2 exchanges sensitive to Arctic Ocean and global climate change feedbacks. In the near-term, further sea-ice loss and increases in phytoplankton growth rates are expected to increase the uptake of CO2 by Arctic Ocean surface waters, although mitigated somewhat by surface warming in the Arctic. Thus, the capacity of the Arctic Ocean to uptake CO2 is expected to alter in response to environmental changes driven largely by climate. These changes are likely to continue to modify the physics, biogeochemistry, and ecology of the Arctic Ocean in ways that are not yet fully understood. In surface waters, sea-ice melt, river runoff, cooling and uptake of CO2 through air-sea gas exchange combine to decrease the calcium carbonate (CaCO3) mineral saturation states (Ω) of seawater while seasonal phytoplankton primary production (PP) mitigates this effect. Biological amplification of ocean acidification effects in subsurface waters, due to the remineralization of organic matter, is likely to reduce the ability of many species to produce CaCO3 shells or tests with profound implications for Arctic marine ecosystems

http://adsabs.harvard.edu/abs/2009BGeo...6.2433B

 

[sylas]

I guess I have a number of issues with the standard explanations for the physics of global warming (and thanks to sylas and Xnn for indulging me here):

No problem; questions are good!

First, the Stefan-Boltzmann equations are the fundamental equations governing radiation physics and temperature. I really think that global warming theory needs to be consistent in some form with these proven and successful equations.

I think I just showed that it is, didn't I?

Let me make one quick suggestion; as an advertisement. I think you are going to love this.

Ray Pierrehumbert of the University of Chicago is about to bring out a new undergraduate level textbook on climate science, and the book is really excellent for someone who wants just the science and who loves maths -- which seems like it might be you. It gets very technical, but you can dip into bits of it at a time. The whole draft is up on the website as a link to an 18 Mbyte pdf. The book is basically finished, and it is going to publishers soon, and this draft will be removed, apparently. Get yourself a copy now, while you still can! I have found this a really useful resource for learning about the underlying background and physics of energy flows in the atmosphere.

The web page for the book is The Climate Book, and the link to the pdf is in "Current draft" and he's still soliciting comment on this draft. When the book comes out, it will be

• Pierrehumbert, Ray. "Principles of Planetary Climate" (Cambridge University Press, 2010)

This goes through basic underlying physics to let you infer (or at least understand how to infer) from first principles such things as lapse rate, tropopause height, surface temperature, and so on, for essentially any planet. It is designed to be used as a teaching text, in which students solve such problems at all levels of detail, up to major computing projects. The book also comes with lots of supporting computer code. In brief, this does climate without weather. It goes very deep into simple energy flow models without using the fluid dynamics that would be needed for all the details of circulation and currents in the atmosphere and oceans.

Chapter 2 is thermodynamics in a nutshell, and chapter 3 is elementary models of radiation balance -- and specifically this is where Stefan-Boltzman law is introduced.

Third, there are four different levels of the atmosphere which are emitting at 240 W/m2. Traditionally, the tropopause is defined as the level where the Earth is in equilibrium with the Solar forcing - the first level where that occurs is about 4 kms up - lower than the top of Mount Everest and lower than the definition of the tropopause.

The atmosphere is transparent, to varying degrees. If you look at a thin slice of atmosphere at a specific level, it radiates almost nothing. When you look downwards, you are receiving radiation from all the levels below. The atmosphere is not a grey body. That is a useful teaching simplification to get started on some of the principles, but in general you can't actually use Stefan-Boltzman laws. You need frequency dependent equations, or the Planck radiation laws. Here's typical spectrum of emission from the top of the atmosphere.

I've added some labels to point to various features. As you can see, the spectrum is not a simple blackbody spectrum. In some bands, the atmosphere is pretty much transparent. In these bands, the spectrum follows closely the curve for a temperature of about 288K; this is thermal radiation coming up from the surface.

In other bands, the atmosphere is almost opaque. The "saturated region" is an example, and here the curve closely follows a spectrum for close to 220K, which is the temperature of the tropopause and lower stratosphere. Basically, the only radiation in this band that can escape to space is emitted from high in the atmosphere, where it is cold. This is mainly a CO₂ absorption band.

The complex behaviour on the left hand side of the diagram is caused mainly by the greenhouse effects of water vapour, which is not well mixed throughout the atmosphere, and hence does not have a simple relationship to a particular temperature. The effective emission altitudes in this band are somewhere in the troposphere.

Now in your diagram, the vertical axis is distance. Physically, it is easier to use pressure as a vertical co-ordinate, as this actually tells you the mass of the atmosphere at any level. Check out Earth Atmosphere Model, an education site at NASA. This represents the atmosphere in three bands: the troposphere with temperature falling with altitude, the lower stratosphere with near constant temperature, and the upper stratosphere with temperatures rising with altitude. In this model, the pressure tells you that about 2.5% of the atmosphere by mass is above the lower stratosphere... the region of your graph with constant temperature. Everything above that has minimal effect on Earth's energy balance. It's just too thin.

At any given altitude, you will have radiant energy flowing up, and down. As well as this, in the troposphere you have energy flowing upwards by convection, including latent heat. This is what maintains the lapse rate in the troposphere. At each level, you absorb a small amount of the radiation, and also emit a small amount based on temperature, according to the frequency dependent Plank radiation laws.

This all gets very technical in full detail, but by the time you finish chapter 4 of the text, you have pretty much what you need to explain and derive temperature profiles in an atmosphere of a given composition and with a given solar input.

Fourth, all the effective action of the greenhouse effect operates below this 4 km level. We use the term "Emissivity or even the Lapse Rate" but isn't this really just the time delay it takes for an Infra-Red photon from the surface to random walk/bounce around the atmosphere and the surface before it reaches the 4 km level and eventually escapes back into space.

The level of the tropopause varies with latitude. Emissivity and lapse rate has nothing at all to do with time delays. Lapse rate is mostly determined by the thermodynamics of adiabatic movement of air. Emissivity is simply a measure of how effective a material is at interacting with radiation. It is frequency dependent, and in an atmosphere you have emissivity per unit mass, which ends up letting you define an "optical depth", or a measure of transparency.

Fifth, since these issues are so complicated and prone to error, why do we not look at the empirical evidence of the paleoclimate to provide an independent verification of the theory. Since the issues are so theoritical, we should go back to ground and see what has really happened in the climate per doubling of CO2. The actual/estimated temperature and CO2 history of the climate does not verify the 3.0C per doubling estimate. The paleoclimate is only consistent with 1.0C to 1.5C per doubling.

We do look at paleoclimate. But the available data is not sufficient to give you great accuracy; I have never seen anyone proposing such a tightly constrained sensitivity estimate from paleoclimate data. Neither have I seen such a low estimate. Do you have a reference?

The most important period for helping constrain climate sensitivity is the Last Glacial Maximum.

• Thomas Schneider von Deimling et al (2006) Climate sensitivity estimated from ensemble simulations of glacial climate in Climate Dynamics 27(2-3) pp 149-163.

From the abstract:

Our inferred uncertainty range for climate sensitivity, constrained by paleo-data, is 1.2-4.3^oC and thus almost identical to the IPCC estimate. When additionally accounting for potential structural uncertainties inferred from other models the upper limit increases by about 1^oC.[/color]​

Maybe I am way off base here, but these issues are not addressed in the standard explanation. It only takes a 25% error in the estimates from the standard explanation to make a huge difference in the global warming per doubling estimate.

You are not at all off base in noting that sensitivity estimates are very uncertain. They tend to be in the range 2 to 4.5 degrees per 2xCO2. However, as I have noted, this sensitivity depends on the various complex feedback processes at work, and cannot be inferred from a simple non-feedback Stefan-Boltzman treatment.

Cheers -- sylas

 

[Xnn]

We use the term "Emissivity or even the Lapse Rate" but isn't this really just the time delay it takes for an Infra-Red photon from the surface to random walk/bounce around the atmosphere and the surface before it reaches the 4 km level and eventually escapes back into space.

No, emissivity and the lapse rate are two entirely different properties from each other and from the time it takes a photon to bounce around.

When a photon enters Earth atmosphere 1 of 2 things happen.
First, it might just be reflected and will immediately exit the Earth atmosphere.
In this case, the time is measured in nanoseconds since light travels so fast.
Second, it might be absorbed. If it gets absorbed, then it will be re-radiated according to the stefan Boltzmann law. By this law, the re-radiated energy will be somewhere in the infrared part of the spectrum which is readily absorbed by all the greenhouse gases and clouds in the atmosphere. I've never seen any authoritative estimate of how long it takes these infrared photons to make it into outer space, but I know that some of them never do. Instead, the energy is transported by thermals or water vapor. That it, mechanical process are important within the troposphere.

Anyhow, emissivity of the atmosphere is basically the ratio between the outgoing infrared radiation at the top of the atmosphere compared to the flux on the surface. It is a unitless number as it is just a ratio. CO2 levels have a direct influence on emissivity.

Lapse rate is how quickly the atmosphere cools off with elevation. There is probably some complicated relationship between emissivity and lapse rate, but I've never seen one.

Fifth, since these issues are so complicated and prone to error, why do we not look at the empirical evidence of the paleoclimate to provide an independent verification of the theory.

Sylas provided a good response, but I'll like to add the the middle plicone is also being studied. The conclusions are that there is more warming found during that time than can be explained with the standard 2-4.5C/CO2 doubling. This is due to changes in vegetation and melting of Greenland and Antarctica; feedbacks which have not been taken into account by most climate models.http://www.giss.nasa.gov/research/features/199704_pliocene/page2.html

 

[ViewsofMars]

I'm impressed by all contributors! :) Everyone is eager to add to the pot of information. I do like that.

 

[ViewsofMars]

Sylas provided a good response, but I'll like to add the the middle plicone is also being studied. The conclusions are that there is more warming found during that time than can be explained with the standard 2-4.5C/CO2 doubling. This is due to changes in vegetation and melting of Greenland and Antarctica; feedbacks which have not been taken into account by most climate models.


http://www.giss.nasa.gov/research/features/199704_pliocene/page2.html

Xnn in a previous article I presented stated, "The Arctic Ocean marine carbon cycle: evaluation of air-sea CO2 exchanges, ocean acidification impacts and potential feedbacks . . . ." That was my third posting on the previous page.

May I please see the climate models you are referring to that don't take into account the
'melting of Greenland and Antarctica which represent to you 'most climate models'. Thanks.

 

[ViewsofMars]

An internationally known peer-reviewed journal NATURE has an article and commentary in the News section.

Published online 16 December 2009 | Nature | doi:10.1038/news.2009.1146

Sea level rise may exceed worst expectations
Seas were nearly 10 metres higher than now in previous interglacial period.
Richard A. Lovett

With climate talks stalling in Copenhagen, a study suggests that one problem, sea level rise, may be even more urgent than previously thought.

Robert Kopp, a palaeoclimatologist at Princeton University in New Jersey, and his colleagues examined sea level rise during the most recent previous interglacial stage, about 125,000 years ago. It was a time when the climate was similar to that predicted for our future, with average polar temperatures about 3-5°C warmer than now.

Other studies have looked at this era, but most focused on sea level changes in only a few locales and local changes may not fully reflect global changes. Sea level can rise, for example, if the land is subsiding. It can also be affected by changes in the mass distribution of Earth. For example, says Kopp, ice-age glaciers have enough gravity to pull water slightly polewards. When the glaciers melt, water moves back towards the Equator. To adjust for such effects, Kopp's team compiled sea-level data from over 30 sites across the globe.

"We could go to a lot of different places and look at coral reefs or intertidal sediments or beaches that are now stranded above sea level, and build a reasonably large database of sea-level indicators," says Kopp.

The team reports1 in Nature today that the sea probably rose about 6.6–9.4 metres above present-day levels during the previous period between ice ages. When it was at roughly its present level, the average rate of rise was probably 56–92 centimetres a century. "[That is] faster than the current rate of sea level rise by a factor of about two or three," Kopp says, warning that if the poles warm as expected, a similar accelleration in sea-level rise might occur in future.

Climate meltdown
The study is "very sophisticated", says Peter Clark, a geologist at Oregon State University in Corvallis. "A lot more of the existing ice sheets at the time must have melted than was thought to be the case," he says, such as parts of Greenland and Antarctica.

The implications are disconcerting, says Clark. If the world warms up to levels comparable to those 125,000 years ago, "we can expect a large fraction of the Greenland ice sheet and some part of the Antarctic ice sheet, mostly likely West Antarctica, to melt. That's clearly in sight with where we're heading."

Jonathan Overpeck, a climate scientist at the University of Arizona in Tucson agrees. "Earth's polar ice sheets may be more vulnerable to climate change than commonly believed," he says.

Furthermore, even if global warming causes seas to start rising toward the levels seen 125,000 years ago, there is no reason to presume that it will proceed at the relatively sedate rate of 6-9 millimeters a year seen by Kopp's study. In part, that's because his study didn't have the resolution to spot changes on a year-by-year basis, so there's nothing to say that the rise during the last interglacial didn't occur in shorter, faster spurts, undetectable in Kopp's data.

Near future warming will also be driven by potentially faster-moving processes than those of the last interglacial. "The driver of [climate change during the last interglacial period] was slow changes in Earth's orbit, happening over thousands of years," says Stefan Rahmstorf, an ocean scientist at the Potsdam Institute for Climate Impact Research in Germany. "We're now set to cause several degrees of global warming within just a century. I would expect this to drive a much faster sea level rise."

Some scientists think that we may already be committed to a future with higher seas than had been expected. "There could be a global warming tipping point beyond which many metres of sea level rise is inevitable unless global greenhouse-gas emissions are cut dramatically, and soon," warns Overpeck.

"I have spent a lot of time talking with national security decision-makers in this country and abroad about the security implications of climate change," says Marc Levy, deputy director of the Center for International Earth Science Information Network at Columbia University's Earth Institute in New York. "I've consistently witnessed an inability on their part to take sea-level risks seriously. This study helps frame the risks in ways that decision-makers can better understand."
•References
1.Kopp, R. E., Simons, F. J., Mitrovica, J. X., Maloof, A. C. & Oppenheimer, M. Nature 462, 863-867 (2009). Article
http://www.nature.com/news/2009/091216/full/news.2009.1146.html

Here is the ARTICLE.

Article
Nature 462, 863-867 (17 December 2009) | doi:10.1038/nature08686; Received 27 February 2009; Accepted 11 November 2009


Probabilistic assessment of sea level during the last interglacial stage
Robert E. Kopp1,2, Frederik J. Simons1, Jerry X. Mitrovica3, Adam C. Maloof1 & Michael Oppenheimer1,2

1.Department of Geosciences,
2.Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, New Jersey 08544, USA
3.Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
Correspondence to: Robert E. Kopp1,2 Correspondence and requests for materials should be addressed to R.E.K. (Email: rkopp@alumni.caltech.edu).

Abstract
With polar temperatures ~3–5 °C warmer than today, the last interglacial stage (~125 kyr ago) serves as a partial analogue for 1–2 °C global warming scenarios. Geological records from several sites indicate that local sea levels during the last interglacial were higher than today, but because local sea levels differ from global sea level, accurately reconstructing past global sea level requires an integrated analysis of globally distributed data sets. Here we present an extensive compilation of local sea level indicators and a statistical approach for estimating global sea level, local sea levels, ice sheet volumes and their associated uncertainties. We find a 95% probability that global sea level peaked at least 6.6 m higher than today during the last interglacial; it is likely (67% probability) to have exceeded 8.0 m but is unlikely (33% probability) to have exceeded 9.4 m. When global sea level was close to its current level (≥-10 m), the millennial average rate of global sea level rise is very likely to have exceeded 5.6 m kyr-1 but is unlikely to have exceeded 9.2 m kyr-1. Our analysis extends previous last interglacial sea level studies by integrating literature observations within a probabilistic framework that accounts for the physics of sea level change. The results highlight the long-term vulnerability of ice sheets to even relatively low levels of sustained global warming.

1.Department of Geosciences,
2.Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, New Jersey 08544, USA
3.Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
Correspondence to: Robert E. Kopp1,2 Correspondence and requests for materials should be addressed to R.E.K. (Email: rkopp@alumni.caltech.edu).
http://www.nature.com/nature/journal/v462/n7275/full/nature08686.html

 

[Xnn]

Xnn in a previous article I presented stated, "The Arctic Ocean marine carbon cycle: evaluation of air-sea CO2 exchanges, ocean acidification impacts and potential feedbacks . . . ." That was my third posting on the previous page.

May I please see the climate models you are referring to that don't take into account the
'melting of Greenland and Antarctica which represent to you 'most climate models'. Thanks.

Here's a link to the http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo706.html".

Here is the abstract:

Quantifying the equilibrium response of global temperatures to an increase in atmospheric carbon dioxide concentrations is one of the cornerstones of climate research. Components of the Earth|[rsquo]|s climate system that vary over long timescales, such as ice sheets and vegetation, could have an important effect on this temperature sensitivity, but have often been neglected. Here we use a coupled atmosphere–ocean general circulation model to simulate the climate of the mid-Pliocene warm period (about three million years ago), and analyse the forcings and feedbacks that contributed to the relatively warm temperatures. Furthermore, we compare our simulation with proxy records of mid-Pliocene sea surface temperature. Taking these lines of evidence together, we estimate that the response of the Earth system to elevated atmospheric carbon dioxide concentrations is 30–50|[percnt]| greater than the response based on those fast-adjusting components of the climate system that are used traditionally to estimate climate sensitivity. We conclude that targets for the long-term stabilization of atmospheric greenhouse-gas concentrations aimed at preventing a dangerous human interference with the climate system should take into account this higher sensitivity of the Earth system.

Most current climate models only include fast acting changes such as water vapor, clouds and sea ice. Such models tend to underestimate the amount of warming found during the middle pliocene. Geolocigal records from the middle pliocene indicate about 30 to 50% more warmer than found with feedbacks included with traditional models. Slow changes in Ice sheets and vegetation have traditionally been ignored by climate models. By slow, we are talking about process that require hundreds of years.

 

[Bill Illis]

There was another study published in Science in December that constrained the CO2 estimates at 3 million years ago to 250 ppm (300 ppm at 3.3 Mya; 325 ppm at 5 Mya; 200 ppm at 8 Mya; 400 ppm at 15 Mya and 350 ppm at 20 Mya) which are consistent/sometimes a little higher than the ones I presented before.

http://www.seas.harvard.edu/climate/seminars/pdfs/tripati.etal.sci.2009.pdf

Published in ScienceExpress in October, reprinted in Science on December 4, 2009

 

[dmtr]

How can I tell that these studies are rigorous enough and can not be falsified? There is virtually no funding directed towards the criticism, why should I expect to see an unbiased picture? True, there is no professional criticism, but why should we expect it?

There was an article in the news: "Climate skeptic Pat Michaels refuses court request to disclose funding sources" - why should he disclose that information? It is his science that we should be interested in, that should be rigorously falsified, definitely not his funding sources.

Here is a nice site (don't worry, no criticism on that site) http://www.heatisonline.org/disinformation.cfm, just search for 'funding'. Why cutting the funding for professional skepticism should be considered as a good, well balanced approach?

 

[Xnn]

Bill;

Wow! That's a very impressive paper.

When pCO2 levels were last similar to modern values (greater than 350 to 400 ppmv), there was little glacial ice on land, or sea ice in the Arctic, and a marine-based ice mass on Antarctica was not viable.

What they mean by marine based-ice mass, is that glaciers and ice shelves were not able to exist at sea level and were constrained to higher inland elevations of the continent.

The highest estimates of pCO2 occur during the Mid-Miocene Climatic Optimum (MMCO; ~16 to 14 Ma), the only interval in our record with levels higher than the 2009 value of 387 ppmv. Climate proxies indicate the MMCO was associated with reduced ice volume and globally higher sea level (25 to 40 meters) (3), as well as warmer surface and deep-water temperatures (2, 20).

From the charts; it looks like CO2 levels were around 440 ppm (375 to 475) during the MMCO.

Currently, CO2 levels are rising about 2ppm/year. So, we could reach 440 ppm within 25 years.

 

[Xnn]

How can I tell that these studies are rigorous enough and can not be falsified? There is virtually no funding directed towards the criticism, why should I expect to see an unbiased picture? True, there is no professional criticism, but why should we expect it?

Actually, there is a healthy amount of professional criticism. The trick is discerning between legitimate scientific criticisms and those that are politically motivated. Generally, if somebody publishes legitimate scientific research, it makes its way into the more prestigeous science journals where it is read by a number of knowledgeable people. Then other researchers will attempt to repeat the work or conduct additional studies that either extend the knowledge or contradict it. It's a continuous ongoing process.

When it comes to climate studies, every few years there is a collection of scientists that get together, review all the new papers and write up a summary. If something is questionable, or not well understood, then it is identified as having a low level of understanding.

Here is a link to the 2007 http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html" .

 

[dmtr]

Actually, there is a healthy amount of professional criticism. The trick is discerning between legitimate scientific criticisms and those that are politically motivated. Generally, if somebody publishes legitimate scientific research, it makes its way into the more prestigeous science journals where it is read by a number of knowledgeable people. Then other researchers will attempt to repeat the work or conduct additional studies that either extend the knowledge or contradict it. It's a continuous ongoing process.

Can somebody give several examples, when some erroneous (and major) paper favoring the global warming was withdrawn due to criticism?

These examples will show very clearly, that there is a healthy amount of criticism. Lack of these examples again will show that there is no criticism. And you know what that signifies.

 

[baywax]

Criticism comes easily to many!

Can somebody give several examples, when some erroneous major paper favoring the global warming was withdrawn due to criticism?

United Press International
01-22-2004
Cosmic cause to global warming discredited

WASHINGTON, Jan 22, 2004 (United Press International via COMTEX) -- Putting the blame for global warming on cosmic rays is just so much hot air, say 11 scientists writing in the American Geophysical Union's journal Eos.

The article in the Jan. 27 issue of Eos claims a recent paper attributing most climate change on Earth to cosmic rays is incorrect and based on questionable methodology.

Astrophysicist Nir Shaviv and geologist Jan Veizer wrote in the Geological Society of America's journal GSA Today they found a correlation between cosmic rays and temperature evolution over hundreds of millions of years, and ...

http://www.highbeam.com/doc/1P1-89667992.html

Climate Alarmists will be Discredited in 2008
Share: by atomcat | January 10, 2008 at 07:36 am
585 views | 2 Recommendations | 1 comment2008 will be the year that the climate alarmists will be discredited
Media Promotes Global Warming Alarmism by Jack Kelly at RealClearPolitics via Yahoo News:

About this time last year, Dr. Phil Jones, head of the Climatic Research Unit of East Anglia University in Britain, predicted 2007 would be the warmest year on record.

It didn’t turn out that way. 2007 was only the 9th warmest year since global temperature readings were first made in 1861.

2007 was also the coldest year of this century, noted Czech physicist Lubos Motl.

Both global warming alarmists like Dr. Jones and skeptics like Dr. Motl forecast that this year will be slightly cooler than last year. If so, that means it will be a decade since the high water mark in global temperature was set in 1998.

And the trend line is down. Average global temperature in 2007 was lower than for 2006, 2005, 2004, 2003, 2002 and 2001. November of last year was the coldest month since January of 2000, and December was colder still. “Global warming has stopped,” said David Whitehouse, former science editor for the BBC. “It’s not a viewpoint or a skeptic’s inaccuracy. It’s an observational fact.”

http://www.nowpublic.com/environment/climate-alarmists-will-be-discredited-2008

Central Plank Of Global Warming Alarmism Discredited

Paul Joseph Watson
Prison Planet
Monday, April 14, 2008
One of the central philosophies of climate change alarmism and an image that adorned the cover of Al Gore’s An Inconvenient Truth - the contention that global warming causes deadly hurricanes – has been completely discredited by the expert who first proposed it.
Hurricane buff and professor of Atmospheric Science at MIT Kerry Emanuel asserted for over 20 years that global warming breeds more frequent and stronger storms and he shot to prominence just one month before Hurricane Katrina in 2005 when he delivered the "final proof" that global warming was already causing extreme weather events and wrecking livelihoods.

Emanuel was subsequently acknowledged with a place in Time Magazine’s "100 People Who Shape Our World" list.

Al Gore was so inspired by Emanuel’s research that he devoted the iconic front cover image of his 2006 movie An Inconvenient Truth to his warning, portraying a hurricane emerging from a Co2-belching smokestack.


An inconvenient cover image – Al Gore’s depiction of global warming’s contribution to hurricanes has been completely discredited.

Unfortunately for the church of environmentalism, who ceaselessly profess to have a monopoly on truth and insist that "the debate is over" on global warming, Emanuel has completely recanted his position and now admits that hurricanes and storms will actually decline over the next 200 years and have little or no correlation with global temperature change whatsoever.

http://www.infowars.com/central-plank-of-global-warming-alarmism-discredited/

Here is the latest sampling of studies and scientists debunking Mann's "new hockey stick." Updated as of September 25, 2008.

http://74.125.155.132/search?q=cach...+discredited&cd=5&hl=en&ct=clnk&client=safari

Ocean Fertilization 'Fix' For Global Warming Discredited By New Research

ScienceDaily (Nov. 30, 2007) — Scientists have revealed an important discovery that raises doubts concerning the viability of plans to fertilize the ocean to solve global warming, a projected $100 billion venture.

http://www.sciencedaily.com/releases/2007/11/071129132753.htm

POZNAN, Poland - The UN global warming conference currently underway in Poland is about to face a serious challenge from over 650 dissenting scientists from around the globe who are criticizing the climate claims made by the UN IPCC and former Vice President Al Gore. Set for release this week, a newly updated U.S. Senate Minority Report features the dissenting voices of over 650 international scientists, many current and former UN IPCC scientists, who have now turned against the UN. The report has added about 250 scientists (and growing) in 2008 to the over 400 scientists who spoke out in 2007. The over 650 dissenting scientists are more than 12 times the number of UN scientists (52) who authored the media hyped IPCC 2007 Summary for Policymakers.

The U.S. Senate report is the latest evidence of the growing groundswell of scientific opposition rising to challenge the UN and Gore. Scientific meetings are now being dominated by a growing number of skeptical scientists. The prestigious International Geological Congress, dubbed the geologists' equivalent of the Olympic Games, was held in Norway in August 2008 and prominently featured the voices and views of scientists skeptical of man-made global warming fears. [See Full report Here: & See: Skeptical scientists overwhelm conference: '2/3 of presenters and question-askers were hostile to, even dismissive of, the UN IPCC' ]

http://smarteconomy.typepad.com/sma...issent-over-manmade-global-warming-claim.html

 

[dmtr]

Criticism comes easily to many!

What you gave is a list of 'criticism' papers (and indications that some of them were withdrawn, good science at work!). I was not asking for it. Let's try to make a list of withdrawn papers favoring the climate change.

Some of the papers favoring the climate change should have been erroneous. If there is a healthy criticism, these errors should have been spotted and the papers withdrawn. It would be a good indicator of a good science.

 

[Skyhunter]

Some of the papers favoring the climate change should have been erroneous. If there is a healthy criticism, these errors should have been spotted and the papers withdrawn. It would be a good indicator of a good science.

This is a false assumption.

Each paper stands individually on it's own merits. Papers are submitted to a publisher for peer review. When a paper passes the peer review it is published in the journal. If it does not pass review it can be corrected and resubmitted. I have never heard of a paper being withdrawn.

Take the time to understand the underlying physics, then you won't need to speculate about the science. Basing your judgment on how many mistakes are made is not very scientific.

 

[dmtr]

I have never heard of a paper being withdrawn.

Well. I have. It is a part of the normal scientific process. There are always mistakes and withdrawn papers. I can give you any number of examples in biology, physics, cosmology, etc. Withdrawn papers is a good indicator that errors are being spotted, that some healthy criticism is present.

Basing your judgment on how many mistakes are made is not very scientific.

On how many mistakes have been caught.

 

[sylas]

Well. I did. It is a part of the normal scientific process. There are always mistakes and withdrawn papers. I can give you any number of examples in biology, physics, cosmology, etc. Withdrawn papers is a good indicator that errors are being spotted, that some healthy criticism is present.

Papers are not usually withdrawn merely for being erroneous. To actually withdraw a paper is very unusual, and usually indicates something more drastic; fraud or plagiarism.

I'm not sure how useful it is to look for recognized errors in papers; but it can be an interesting insight into the scientific process. I suggest setting the bar a bit lower.

I can give examples of papers that have had significant corrections acknowledged in print by the authors. These are not merely new improved results, but specific identification of a clear source of error that had a major impact on the result.

This is not particularly unusual, I think; but generally it will involve an isolated unusual claim that turns out to have been overstated, rather than identification of some error which undermines a whole well established body of theory. That is what would be required to show anthropogenic global warming was based on an error.

The examples I am thinking of are not exactly "skeptic" papers, but they did stand as a challenge to conventional ideas of climate, and turned out to have been incorrect, as acknowledged by everyone involved.

• Tropical warming trends in the troposphere were substantially underestimated by John Christy's satellite temperature estimating group at the University of Atlanta Huntsville (UAH). The erroneous measure was a substantial conflict with climate models, but was resolved in 2005 when it was pointed out that they had made a sign error in corrections for a day night cycle. The error was acknowledged and corrected as soon it was pointed out. The UAH group continues to publish, of course, using the new corrected data and suitably revised conclusions.
• Estimates of a sharp rise in Earth's albedo were published in 2004, and again in 2006, based on measurements of reflected light from the Moon by Palle and colleagues. This was presented as indicating an albedo based forcing much larger than the carbon dioxide forcing. However, the rise was actually due to problems with a telescope, and the corrections were published in 2008 by the same group.
• Ocean warming estimates by Josh Willis, based on the network of robotic floats (ARGO), initially indicated significant cooling of the oceans. These results were discovered to have been distorted by problems with the pressure sensors on floats. These floats would regularly sink down and record temperature profiles with depth, then resurface and transmit results. But the sensors meant that the depth information was incorrect, and when corrected in 2008, the cooling effect was discovered to be an error.
• Steven Schwartz in 2007 published a very low estimate for climate sensitivity based on relaxation times in the temperature record. The paper was quickly followed by a rash of rebuttals in the same journal, which Schwartz recognized and in 2008 published a follow up substantially revising the sensitivity estimate upwards.

I am sure it will not be hard to add to this list.

Cheers -- sylas

 

[dmtr]

Papers are not usually withdrawn merely for being erroneous. To actually withdraw a paper is very unusual, and usually indicates something more drastic; fraud or plagiarism.

I'm not sure how useful it is to look for recognized errors in papers; but it can be an interesting insight into the scientific process. I suggest setting the bar a bit lower.

Here is a recent example of a major paper being retracted. I can give you quite a few in biology and chemistry. http://www.nature.com/news/2009/091209/full/462707a.html
This withdrawal is a good indicator that there is healthy criticism in chemistry. Peer review can't spot everything. And it is ok.

EDIT: Yeah, it's an excellent idea to set the bar lower and look for significant corrections as well.

The examples I am thinking of are not exactly "skeptic" papers, but they did stand as a challenge to conventional ideas of climate, and turned out to have been incorrect, as acknowledged by everyone involved.

I'm asking for examples of corrections and retractions of papers that did NOT stand as a challenge to conventional ideas of climate.

 

[sylas]

I'm asking for examples of corrections and retractions of papers that did NOT stand as a challenge to conventional ideas of climate.

Oh, I know. I'm just proposing an easier target for baywax to consider, and demonstrating this is in principle possible to answer. I think he'll still find the weaker challenge difficult. All the examples I have given are the other way around, indicating problems in challenges to conventional ideas.

This is as one should expect; it's the unusual or surprising results that are most often afflicted with errors; and the main body of conventional climate is based on an enormous amount of mutually supporting evidence.

The ball is now with baywax to see if he can find acknowledged errors. Not merely disagreements that are as subject to error as the original work... and perhaps more so.

Cheers -- sylas

 

[dmtr]

Oh, I know. I'm just proposing an easier target for baywax to consider, and demonstrating this is in principle possible to answer. I think he'll still find the weaker challenge difficult. All the examples I have given are the other way around, indicating problems in challenges to conventional ideas.

Sure. It's an excellent idea to look for significant corrections as well.