Water vapour is not the dominant greenhouse gas

OK, so it may not surprise you that I'm going to have to qualify the headline a bit lower down, but the point itself remains.

Why does anyone care about this? Answer, of course, that one of the std.septic arguments is "there is no point in worrying about human emissions of CO2, because water vapour is the dominant GHG". This argument is nonsense (which is why there is no k) but if you don't know the science thats no obvious. So...

Lets start by looking at what fraction of the current GHE *is* caused by water vapour. Its not terribly easy to find these estimates, mostly because scientifically its not an interesting question (see below). The ones I've found I've collected onto the wiki page Greenhouse effect; refs to all of this are available there. Probably the best one is IPCC '90 (first report; sadly not online) which estimates 60-70%. I presume thats a global value. Locally, instantaeously, it would vary wildly according to local conditions. If you start omitting various gases, you can push the numbers up high: Soon and Baliunas quote 88%, considering only WV and CO2. Lindzen quotes 98% (Even if all other greenhouse gases (such as carbon dioxide and methane) were to disappear, we would still be left with over 98 percent of the current greenhouse effect). I don't think thats plausible (incidentally I seem to have misrepresented it on the wiki page... oops). He doesn't quote a source for this value and may well have made it up. But apart from providing word-bites for skeptics to take out of context, there doesn't seem to be much point in these numbers. Because the main point is...

Water vapour is a "reactive" GHG with a short atmospheric lifetime of about 1 week. If you pump out a whole load of extra water vapour it won't stay in the atmosphere; it would condense as rain/snow and we'd be back to where we started. If you sucked the atmosphere dry of moisture, more would evaporate from the oceans. The balance is dynamic of course: humidity of the air varies by place and time, but its a stable balance.

In contrast, CO2 has a long lifetime (actually calculating a single "lifetime" for it doesn't work; but a given CO2 pulse such as we're supplying now will hang around for.. ohh... a century or more). It doesn't rain out (amusing factoid: the surface temperature of the deep interior Antarctica in winter can be colder than the freezing point of CO2; but this doesn't lead to CO2 snow (sadly, it would be fun) because the freezing point is lower because of the lower pressure because its higher up). So if you put in extra CO2 the climate warms a bit; because of this move WV evaporates (it doesn't have to, but just about all models show that the relative humidity tends to be about constant; so if you heat the atmos that means that the absolute humidity will increase). This in turn warms the atmosphere warms up a bit more; so more water gets evaporates. This is a positive feedback but a limited one: the increments (if you think of it that way) get smaller not larger so there is no runaway GH effect.

So: adding CO2 to the atmosphere warms it a bit and ends up with more WV. Adding WV does nothing much and the atmos returns to equilibrium. This is why WV is not the *dominant* GHG; its more like a submissive GHG :-)

[Update: 2005/02/09: http://www.radix.net/~bobg/climate/halpern.trap.html is worth reading]


Peter Hearnden said...

I'll vote for this. Btw, how did I miss this blog??

Anonymous said...

Another vote from me.

Anonymous said...
This comment has been removed by a blog administrator.
Anonymous said...

Have you ever heard of photosynthesis?

tom.brogle@ntlworld.com said...

Water vapour is there all the time being replaced and absorbing heat all the time .What happens to the latent heat of evaporation when it condenses? It must surely warm the air.
I suspect the turn over of CO2 is much the same as H2O since it is exceedingly soluble in water and must be washed out of the by rain.

Belette said...

Latent heat tranport is an important part of the atmos heat cycle.

CO2: no: the turnover time is very slow (lifetime is 100's of years) - rainfall removes very little.

Anonymous said...

Explain how gas molecules cause a greenhouse effect. The mechanism depends on the density of gas molecules per unit atmospheric volume. Once you do that, you will see the entire premise of the argument about the unimportance of water vapor versus CO2 is false and the post is bunk.

Anonymous said...

You say carbon dioxide doesn't rain out! Why not? Carbon dioxide is very soluble in water! Limestone dissolution is a direct result of the carbon dioxide dissolved in rain water (Solubility in water @STP 1.45 kg/m³, from Wikipedia). The formation of caves and the acidification of soils is a direct result of carbon dioxide solution in rain water. Humans have been burning limestones for many thousands of years (pre-industrial time) in order to use the lime to neutralize acid soils for agricultural use.

The only significant carbon sources and sinks are inorganic. The world's carbonate inventories exceed the biological carbon inventories by millions of times. Oceanic carbonate deposits and volcanic carbon dioxide emissions are the primary carbon cycle components.

Please provide a scientific basis for your statement: "CO2: no: the turnover time is very slow (lifetime is 100's of years) - rainfall removes very little." It appears contrived and baseless. Quoting political and eco-agenda bases sources is pointless.

For your interest there is a considerable body of knowledge available for rain water based CO2 chemistry at Speleogenesis (http://www.speleogenesis.info)

Anonymous said...

Natural pH of Rain Water:

David Marshall said...

I am baffled why there are so few atmospheric scientists with a simple education in physics. Water in it's vapour form got that way because of the heat it absorbed. This absorption is unique to water which modifies the blanketing effect of GHG (Greenhouse Gas)and protects our planet from becoming like Venus. There is, however, a titration limit to how much our water vapour protection can protect us. The IGY studies have shown that an "Ice Age" can occur within a few hundred years and take thousands of years to retreat. Get your info straight. CO2 does not absorb heat, it blankets it, much like very thin plastic wrap around your body will trap heat within and make you sweat. It need only be a few molecules thick to create a reflective coating that will trap the most dangerous radiation from escaping to space from our planet. That radiation is Infra Red (IR). The reason for this inward reflection has to do with the nature of CO2. It can absord many wavelengths of light and re-emit that energy very quickly as IR radiation. Water, however, requires massive amounts of heat per gram to turn into vapour. That heat comes from IR directly and from re-radiated heat converted by impurities in water that have absorbed other wave lengths of light. The largest impurity in water at this time is CO2 and that impurity is creating H2CO3, an acid which is, right now, eating the Great Barrier Reefs choral and destroying massive amounts of CO2 absorbing forest and plant life. It's time for facts folks not political "wishful" ideology.

Anonymous said...

Scientists who don't like to speculate are real scientists. They have to stick to the measurable facts and not let cultural trends sway their theories. On that note, of course there's global warming, how do you think we got out of the Ice Age. Geesh, don't people watch historical cartoons anymore (i.e. Ice Age: the Meltdown).

All kidding aside, scientists have to find solid verifiable and measurable link of global warming with GHGs. I don't like the "CO2 increase = global warming" argument. It's so unscientific. Just because something happened concurrent to another, it doesn't necessarily make it the cause. That's like saying "increase in football fanaticism since 1950 = global warming."

One research in particular that I would like to see is regarding the glacial records. Can it be determined if there have been hotter periods than the present? If so, how hot can mother nature get and what was the span of time sustained?

From science, I expect quantifiable, measurable, demonstrable proof. From politics, I expect spin. Let's keep them distinct, people.

Anonymous said...

if anyone knows the answer plz email me ASAP, my email address is maxliu90@yahoo.de

So can anyone tell me why does GHG absorb heat? is it becuase of their bonds? or is it because of their unusally high specific heat? plz help

Anonymous said...

if anyone knows the answer plz email me ASAP, my email address is maxliu90@yahoo.de

So can anyone tell me why does GHG absorb heat? is it becuase of their bonds? or is it because of their unusally high specific heat? plz help

Magnus Andersson said...

Why is water vapour concentration stable? The warmer atmosphere the more water vapour can it hold. This physical rule any child knows of.

So this positive feedback should make the atmospheres water vapour content unstable, and so the temperature. But this unstableness has its limits of curse, as in any complex system/environment. But the limited contribution from additional CO2, why is that more important than large differences in the water vapour content?

BTW: Also the CO2 has its balance in absorbition as well as emmisions from the oceans.

Anonymous said...

Just because water vapor has a short lifetime in the atmosphere compared to CO2 doesn't make it any less dominant. Article makes no sense to me. Sounds like arm waving.

Tango said...

Good blog.

Geoff said...

The transient nature of WV compared with that of CO2 is a mute point. It is the percentage that each contributes to GW and from most objective data I've seen CO2 is a minor player compared with WV.

Anonymous said...

WV accounts for 95% of the GH effect. CO2 less than 4%.

OF all atmospheric gases N is 78%, O is 21%, WV is 0 to 4% and CO2 is .036%

Say again what impact man has?

Anonymous said...

This is a great discussion... I want to add my own question to the mix - but first I want to point out that in my research thus far I have not found a reputable quantified source that shows the WV factor at anything less than 30%! (and up to 99%) All the while, CO2 is always significantly lower... .2%-7%.

Even if we COULD calculate accurately the effects of all GHG's on our atmosphere, and then create an atmospheric AND climatic model that MIGHT give us some insight in to our future temperatures/weather/climate outlook, WHAT KIND OF EFFECT IS THE SOLAR CYCLE HAVING ON ALL OF IT? If it is significant, then our model just got infinitely more complex, because we are now combining climatic/atmospheric weather models of the Earth with those of the Sun... so the variables of uncertainty just keep on growing!!! If you're an advocate for conservation and minimizing fossil fuel consumption/emissions, saving rain forests, preserving habitats, saving animals from extinction, etc., GOOD FOR YOU (I AM), but you may want to re-evaluate your reason. I just love the outdoors, and I like clean air above the city I live in... oh, and I like the idea of giving my hard-earned money to somebody other than an oil company once in a while... so shoot me! As far as Global Warming is concerned, the only noticeable relationship I see between human emissions and Global climate change is the next election.

If there are sources out there for Solar Cycles and the effect on Earths Atmospheric AND Surface temperatures, PLEASE SHARE!

Anonymous said...

I just posted my thoughts, and I had another realization as I continued my research. The question was raised about "positive feedback" created from human emitted CO2 indirectly increasing the earths ability to hold water vapor in the atmosphere, therefore contributing to GW by affecting the levels of Water vapor, the most abundant GHG... I think this is an educated, well-made point by those arguing FOR global warming, and should be considered. So here is my consideration: our overall effect would (mathmatically) still be minor, although not quite as "insignificant." The indirect effect of CO2 levels on Water Vapor increases would have to be proportionally small, relative the the % of effect the (varying) suspect levels of CO2 actually have on the whole climate system. But there is yet ANOTHER variable that contends with the "CO2 Positive Feedback" and its potential to increase Water Vapor levels... (therefore increasing global temperatures)... MORE WATER VAPOR in a warm atmosphere ALSO means more CLOUDS AND RAIN... and the weather model would need to determine this increase as well, because water vapor in cloud form would potentially act as am atmospheric "coolant" thereby reducing (or canceling out... or decreasing) possible temperature changes... I think a qualified atmospheric phd might even find evidence to support the possibility of a GLOBAL COOLING effect (AH, here come the men in white coats?!) thus arguing the possibility of speeding up our entrance in to the next ice age! (afterall, if you look at temperature models dating back 500 million years, there are 2 major points of atmospheric CO2 record lows. Approximately 300 million years ago, and now. (http://en.wikipedia.org/wiki/Image:Phanerozoic_Carbon_Dioxide.png)

When all is said and done, even the argument that "increased CO2 levels could indirectly increase our WV levels, thereby contributing even further to the possibility of a run-away greenhouse effect..." is rendered insignificant. I don't use "invalid" simply because we could POSSIBLY show a MINISCULE amount of additional warming effects under this theory... but I feel it is "cancelled out" until we can model the CLOUD effects of the additional water vapor, and the resulting atmospheric cooling abilities.

Anonymous said...

http://en.wikipedia.org/wiki/Image:Phanerozoic_Carbon_Dioxide.png -- this is the link for the 500 million year model of CO2 levels... a little bit broader look at the earths history then we usually get from the GHG crowd... (less than 1 million years)

Anonymous said...


Anonymous said...

is there anyway to delete this. I think everyone should be allowed a voice to be heard, but that voice must me knowledgeable with data to back it up, none of the BS presented. What started off as perhaps a decent argument turned into a joke.

Captain Mike said...

OK, here are some data to chew on: the ice core record shows that over the last 650,000 years there have been many periods in which both the global temperature and the CO2 levels have been significantly higher and lower than today. The record also shows that when global temperature rises it is always FOLLOWED by a rise in CO2 some 800 years later.
It turns out that the oceans are also CO2 absorbers, soaking up CO2 in inverse proportion to their temperature. (As the temp goes up, the ability to disolve CO2 goes down.) So...the earth warms up, over the next 800 years the oceans gradually warm, releasing CO2. Then the earth cools, and 800 years later the oceans gradually cool and absorb some of the CO2 out of the air.
If the old rule of effect following cause still holds then GLOBAL WARMING CAUSES RISING CO2 LEVELS - not the other way around.
What causes global warming? Well if your house is getting warmer do you immediately look at that tiny bit of insulation in the north corner of the attic, or do you look at your furnace and the thermostat?
The Earth gets warmer (along with all the other planets in the solar system) when the sun's output increases, and cooler when it decreases.
This whole "debate" over global warming is a scam perpetrated by disgruntled leftist upset over the fall of communism. It just a swindle by anticapitalist jerks.

Rolan O. Clark said...

I think I understand the very basic concept of Radiative Forcing but what I am trying to reconcile is the property of water vapor to possibly dissapate heat to the cold sink of space because water vapor is so short lived (a few days?)and that it because it rises as it warms, then cools as it rises because it radiates heat to the cold sink of space and if so does the heat transfer of water vapor exceed the 'trapping' of CO2 and will more WV result in more clouds, more cooling, more blocking of the suns energy, more snow, more refelctions back to space, less absorbed by earth to radiate as IR?? Does CO2 really 'absorb' and if so at what point will it not accept any more energy from IR earth radiation then does it 'repel' and how efficient is CO2 to 'absorb' IR, for example, if I have 10 photons of IR that 'intercept' CO2 molecules, how many of those photons will impart their energy to the CO2 molecule and what percentage of the energy will be transfered? Then when the CO2 radiates that energy does it cause more water vapor and on and on?

What is the ratio of water vapor molecules to CO2 molecules, say at 15 deg C over middle America. I realize that water vapor is an elusive target, minute by minute almost.

Does this make sense??


JamesB said...

In all the research I’ve done I have seen no mention of human generated heat. I agree that once heat is generated it has to go somewhere. It is usually absorbed bythe earth or atmosphere but once absorbed it should raise the temperatures.
We all know that when we turn on the heater in our home we raise the temp to the desired level. If you turn off the heater eventually the temp will fall back down until it reaches the outside ambient air temp. Everything in the house from walls to furnishings absorbs heat and holds it.
If you heat your home to 75 when the ambient outside temp is 30 it can take well over 24 hours for your house to cool to the ambient temp when you remove the heat source. We also know that if the heat source remains rather constant the house will not cool. The earth operates the same way. A constant heat source however small must have an impact on average temps.
The heat generated by 6 BILLION human beings each giving off somewhere between 40-100 watts depending on activity levels. When awake and doing normal daily tasks (not heavy work) most adults generate the equivalent heat of a hundred watt incandescent light bulb. Children generate slightly smaller amounts of heat and all of us generate less heat when sleeping. So maybe we could say the average human heat source equals 75 watts per person or over 6 BILLION 75 watt light bulbs! On the surface that sounds like a huge heat source but when compared to the earth it’s actually rather small. The important thing to remember is that it is a heat source that is on 24/7. Most other man made heat sources are not generating heat 24/7. That much heat being generated every day must have an impact on global temperatures. It is also a heat source that has more than doubled during the same time frame as the global warming. It is still growing faster everyday.
Then we have man as a direct source of CO2. We exhale some amount of CO2 with every breath. Just like our body heat our respiration is a source of CO2. So man himself is a double whamy. We generate heat and our own personal greenhouse gas. Man himself has got to be a factor in global warming. Yet I haven’t seen any mention of this little discussed fact. The simple fact that our numbers have increased by a factor of 2.4 between 1950 and 2000 the same time frame of the most warming can’t be just a coincidence.

JamesB said...

Water Vapor is the single most important greenhouse gas. It accounts for apporx 95-98% of the total volume. It’s effectiveness however is less certain. Depending on who you listen to it can be as low as 60% and as high as 95%. CO2 also has a wide effectiveness window between 3% and 35%. That is for climate science an extremely wide window of uncertainty. With such a huge error factor on the effectiveness of the two primary gases how can anyone possibly claim that man made CO2 is the cause of the current warming trend? Now add to the uncertainty window the fact that man made CO2 only accounts for
approx 5% of the total atmospheric CO2 levels and the error factor expands. Another factor has been detected that affects earths temperature and that’s sun spot cycles. Sun spots run in an 11 year cycle. The higher the sun spot number the more energy reaching the earth and the temperatures rise. There are three other lesser known sun spot activity cycles that cover much longer time cycles. These cycles are now being studied to try and determine their effect on our planet. Right now the sun spot data more closely tracks the temperature curve than CO2 leading some scientists to believe that sun spots and not greenhouse CO2 may be responsible for the current warming trend. Here is a web site discussing sun spots and global warming.

In the paragraphs below I have used my meager math talents to try and determine mathematically the effectiveness of man made CO2. I determined that even using the highest effectiveness values for CO2 from pro global warming web sites the math doesn’t support the theory of man made global warming. I think my math is correct and logically arrived at and I challenge the members of this web site to verify my results. It would be much easier to explain the math in a classroom but I gave it my best shot using words.
I also calculated for both extremes of the effectiveness values just to make sure my conclusions were correct. I also realize that I have over simplified a very complex problem but sometimes that is the best way to look at the data. The more factors you try and include in your calculations the greater the likely hood for error.

If all CO2 contributions equal only 3.6% of the greenhouse effect and man made CO2
is only 5% of that we are left with .18%. Man made CO2 is responsible for .0018 of the
total greenhouse effect. Since 1958 CO2 levels have risen by 66 ppm or a 21% increase.
That figures out to be approx a .75% increase in overall greenhouse effect when factored with the other greenhouse gases. Now let’s assume that all of that is man made CO2. Now depending on who you wish to believe the earth’s average temperature since 1958 has increased by around 1 degree C. The quoted average mean temperature of the earth is around 14 degrees C. A one degree increase equals a 7% change. A 7% total increase in the earth’s temperature cannot be accounted for by .75% increase caused by CO2. Even if total CO2 doubled it would not account for such a large increase in temperature. If total CO2 levels quadrupled during that time period it’s effect might equate to such an increase but that didn’t happen. If the math is correct the rising CO2 levels should account for less than one hundredth of a degree. Now remember that assumes that ALL the increase in CO2 is man made which is unlikely so that one tenth of a degree could be and probably is even smaller. Now let’s assume the numbers are off by a factor
of 10. Let’s further assume that the error is all on the warming side. We then have an increase of .075 of a degree or less than a tenth of a degree. An error on the scale of a factor of 10 is unheard of in science. An error value of +- 10% is closer to the norm. An error factor of ten is one hundred times larger than +- 10%! Let’s go one further step and use the highest CO2 effectiveness figure I’ve seen quoted- 40%. That is CO2 accounts for forty percent of the greenhouse effect when factored in with water vapor and the other gases. That makes mans contribution much more significant. Man made CO2 is usually quoted at 5% so that makes it 5% of 40% or .02 or 2%. Even using the highest figures man’s contribution is only 2% of the CO2 or .8% of the total greenhouse effect. The 1958 levels were 315 ppm in 45 years the CO2 levels increased to 381 ppm a 21% increase. Man’s share 2% of the 1958 levels was 6.3 ppm. That means that to account for the 66 ppm increase man’s contribution would have had to increase by a factor of 10.47 in 45 years! That’s using the worst case figures that are not widely accepted by
science. These figures also assume that natural CO2 levels remained constant an unlikely happening. Also water vapor would have had to remain constant which it did not do. In fact the measurement of water vapor shows a steady increase of 1% per year during most of that 45 years. If the increase of 66 ppm in CO2 levels accounts for the 1 degree C rise in temperature man’s CO2 output would have had to be slightly over ten times higher than 1958. I have seen no data that suggests that man’s CO2 output has increased 10 times in the last 45 years. The world population has only increased by 2.4 since 1950. In fact one graph I saw showed that man’s CO2 output has been fairly stable since 1975 with no significant increases. I will admit that there has to be some cumulative effect and some portion of the CO2 not absorbed by nature stays in the atmosphere from year to year. Unfortunately my scientific abilities do not extend to that subject nor do I have any detailed knowledge of wave length and sun energy spectrum absorption of the
different greenhouse gases. Then there is the little known factor of inner reaction of the different gases. In other words what happens in the atmosphere when CO2 levels rise. Does that rise directly or indirectly affect the levels of water vapor and if so how and vice versa. The above figures also do not take into account any non greenhouse warming factors. Nor does it try and account for changes in the sun’s output that being considered a constant. A few web sites I’ve looked at claim that the earth without the greenhouse effect would have an average temperature around -18 C. That means that the greenhouse actually accounts for a 32 degrees C temperature raise. That means that a 1 degree C rise in temperature equates not to an impressive 7% average increase but a less impressive 3.1% increase. Since the total greenhouse effect is 32 degrees C, one percent equals .32 degrees C and a .75% increase caused by CO2 should equate to a .24 degree C increase in the average earth temperature. That small a temperature change isn’t even as large as the normal temperature fluctuations. I also suspect a number that small would fall within most normal error ranges IE: +- 5%. In fact even a very close tolerance error factor like
+-1% would still cover the temperature increase claimed to be caused by CO2.

I ask the reader in all honesty if anyone of you think that weather and climate research is exact enough to even claim a 1% tolerance? I don’t think that even now scientists have a complete global wide data set to work with in respect to world temperatures. There are large portions of the earths surface where scientists have no temperature data and are forced to estimate from the closest weather reporting station that may be hundreds of miles away. There are places on the earth where temperatures not only haven’t gone up they’ve actually dropped during the last 50 years. When ever man is forced to average anything there is an error factor of some amount. The larger the data area being averaged the higher the error rate should be. For instance how do the scientists average out the fact that a large number of weather reporting stations are in or near large metropolitan areas? Scientists know that temperatures are abnormally higher in urban areas. So before they even start to average out world wide temperatures they first have to determine the urban error and correct for it. Next they have to add in the rural temperatures and determine a recorded average. Now the hard part which is estimating the temperatures from areas with no reporting facilities. They have to in effect create data when none exists! So we now have a combined and corrected data set with three built in errors. The first error rate is the urban correction factor. The second is the normal error found whenever you average any group of numbers. The third and possibly largest is the error rate created during the estimation process that accounts for areas with no data. Actually there is a fourth data error rate which happens when the researchers combine all the data together and estimate an average. All these possible errors could result in a rather large error factor. I’m well aware that error factors can work both ways which is why they are expressed as a plus or minus value. In truth the earth could actually be slightly warmer than what we think. However since the historical average is quite a bit cooler than the temperatures today I suspect the error would most likely be cooler rather than warmer, but I could be wrong. The truth is the scientific research the global warming folks are basing their predictions on in all likely hood has a built in error factor quite a bit larger than the claimed temperature increase they are pointing at to prove their theory! That my friends is bad science!

So if the figures are correct there is no way man made CO2 or for that matter total CO2 increases could possibly account for a one degree C rise in earth’s temperatures. In fact man cannot be responsible for the increase in CO2 since 1958. No doubt man is a contributing factor but we are not the global warming demon. In fact if my figures are correct man isn’t even carrying the pitch fork! I know a one degree C rise doesn’t sound like much and it’s easy to point at the corresponding increase in CO2 and draw the conclusion that CO2 is the cause. Also keep in mind that the way figures are presented have an impact on those viewing the data. For instance if you look at a graph of CO2 levels from 1900 to 2000 the slope of the increase is very pronounced. It has a visual impact factor. If you graph CO2 from 1970 to 2000 that same slope goes from a steep mountain side to a much more gentle slope. Yet those 30 years are when man’s CO2 output has increased the most. If you look at most CO2 graphs the CO2 scale doesn’t go from 0-500 it normally goes from 260-380. This presents the data in the most visual impressive format designed to catch and hold the eye. If you change the scales the impact changes yet the data being displayed remains constant. If the CO2 scale on the graph or chart was increased to include the highest and lowest readings it should be 150-400. If you were to graph CO2 levels using that scale which is more historically accurate the slope would flatten out and be less visually impressive. Is this cheating-no and yes. The data presented is 100% accurate within the chart/graph so there is no cheating on the data. The cheating comes in when you deliberately design the chart/graph to give it a higher visual impact than the data warrants. Graph a child’s growth in two different ways and you’ll see what I mean. Set the scale in years to height. If you present the graph over the first 25 years of life it appears to be a fairly constant growth rate with a few blips here and there. Now use the same data but change the scale in years from 0-25 to 8-16 while keeping the height in inches constant and the entire visual impact to the viewer changes. Because you have compressed the years scale while keeping the height scale constant the slope becomes much steeper. Now take that a step further and also change the height scale and you might end up with close to a 45 degree or greater slope depending on the child. The data hasn’t changed but it’s impact on the viewer certainly has. My point is the viewer has to look at the whole graph and not just the data line. Look at the scales and determine if the impressive data line is in fact impressive at all. Look at the scales and change the values in your head and try and visualize how the data line will change. It isn’t easy to do but with practice you can become fairly accurate in your mental estimates. It doesn’t take very long before you can determine if the graph is an accurate visual presentation of the data or a deliberate attempt to manipulate the data in the strongest possible format in order to visually impress the viewer and thereby enhance the creators point. This type of data manipulation only works with a layperson as experts will see right through it. This visual manipulation of graphed data is done by any number of researchers. Many times the reason is to impress the data visually on the viewer and not necessarily to cheat. It is only the viewer that can really determine if the graph’s creator is attempting to portray or significantly manipulate the data for the sole purpose of furthering an agenda or theory. All of us want to see our ideas put forth in the best light. But to manipulate the data in such a way that the only conclusion the viewer can make of the data supports your theory then you are misrepresenting the data.

Carrick Talmadge said...

William, to clarify it, most of the greenhouse gas effect is in fact from water vapor. That is indeed what the science says. Of the remaining greenhouse gases, about half the effect is from CH4 (methane) CFCs and so forth. These are in the atmosphere only in trace amounts, so it would be relatively easy to cut the anthropogenic greenhouse gas effect in half.

Detractors from the commonly held view on human-generate global warming are actually correct as far as they go with respect to CO2 as a greenhouse gas. It is totally ineffective in our atmosphere, given the presence of water vapor, without going into the details on the physics of why this is so. But this is an established fact, first worked out in the 1860s by the physicist John Tyndall.

What they (like you apparently) don't understand is that CO2 acts as a "greenhouse gas accelerator" in our atmosphere. As usual, Wikipedia has an excellent discussion of the real effect, which has nothing to do with the traditional greenhouse effect.

Anonymous said...

JamesB, you usually don't hear about the human heating effect. But in reality, it's well known among climate scientists, and is called the Urban Island Heat Effect. Scientists, when working with Global Warming data, attempt to compensate for it by subtracting a factor from the data. Unfortunately, this doesn't appear to be the right way to go about it, at least not if the fact that many towns haven't gone up by much in temperature since 1850, but New York City and Tokyo have gone up by about 4 degrees Celcius, with some of the steepest slopes I've seen on any climate graphs. If this is supposed to be a global phenomenon, why does NYC go up while Albany goes down? They're not that far apart. And presumably, Global Warming affects the globe equally. In theory. THis doesn't appear to be working out.

Anonymous said...

Graeme Bird sez:

One of the many faults in this analysis is that it is not water-vapour OR CO2 that is the most important greenhouse gas.

The most important greenhouse gas is LIQUID WATER.

Actually it is water in all its manifestations that keeps this planet warm. Even ice keeps this planet warm.... Except for land ice which only then becomes a force for cooling.

This is one of the many ways the alarmists are coming off the beam. Greenhouse science was developed with reference to the other planets. So they do not think of the oceans except as an afterthought.

Yet it is the oceans and the oceans alone that can store energy long enough for cumulative warming.

Stoat is particularly glaring in his blinkered nature with regards to oceanic heat content. He is a gas and radiation fetishist.

As totally bigoted comments at Roger Peilkes site make clear.

Tomazo said...

I have a BS in Chemistry and an MS in Chemical Engineering. I have all the training required to be a "climatologist" and as such, I must agree that this is the WATER PLANET: its ability to attenuate climate change is no doubt the MOST IMPORTANT impact on our atmosphere and this, in fact, enables a CO2/O2 balance in the biosphere. LeChatlier's principle (and indeed controlled expermiment) informs us that increasing CO2 levels stimulates plant growth, acting to counter heating as does cloud cover created by increased WV. Indeed the climate that produced the abundant fossil fuels we consume were largely in high CO2 environments. Where does one think all that carbon fixation came from???
Yes, I realize I must "produce my facts for scrutiny" by the "stop the world crowd, but I figure if they can avoid doing so, I can as well.

Anonymous said...

This is a great discussion. Thanks to the folks who started it, I have really learned a lot.

One of the most impressive and simple statements IMHO was about the rule of cause-and-effect. Thus, blaming CO2 and methane emissions for Global Warming is like blaming an umbrella for the rain.

As it is commonly agreed, the earth's oxygen-rich atmosphere creates the Greenhouse Effect that allowed the protean enzyme soup to initially evolve which lead to all sorts of plant and animal life evolution.. etc. In my limited understanding this is agreed upon by nearly everyone, and also explains why there is no life at this time on other planets in the solar system.

If we follow this line of thinking, it would mean that the Greenhouse Effect would need to have existed on earth before ANY life. Indeed the composition of the earth after formation would have been the chemical rich rock expelled by volcanic activity and lots of H2O. All life would have followed.

If this is the case, we MUST rule out from the Greenhouse Effect formula any gas that is not biologically produced. Meaning a majority of CO2 as well as Methane and other gasses were simply not present in any significant quantity during the formation of the planet and have not contributed to the initial Greenhouse Effect that facilitated life on earth. CO2 may enhance the reflection of radiation back to earth, but it is clearly not the core mechanism responsible for the process of warming the planet surface.

While CO2 does naturally occur due to geothermal activity, the frequency of such activity is not sufficient to sustain current CO2 levels in the atmosphere. Hence CO2 presence in trace amounts in the atmosphere (some 0.038%) is likely an indication that it is a byproduct of activity by living things, and does not naturally occur in even the quantities described.

Meaning that if CO2 was to be subtracted in whole from the planet's atmosphere, the Greenhouse Effect would still be in place.
And if this is the case, there must be ANOTHER Dominant Greenhouse Gas OTHER then CO2. Hence if our air is also comprised of Nitrogen, Oxygen and Argon it is likely that atmospheric condensation (vapor) is the real force behind GHG. If pure CO2 content led to surface warming, planets such as Mars that have a higher percentage of CO2 in the atmosphere then earth, would be a lot warmer. But Mars is so cold that Co2 condenses into Dry Ice clouds. So clearly mere presence of CO2 does little to affect GH effect.

I believe this simple exercise upholds the comments about cause-and-effect. CO2 and Methane levels increase as a result of global warming and not the other way around.

The actual cause of Global Warming is not your SUV.. and its pretty arrogant of us to think that we have that much sway over the planet's weather system, which in essence is self correcting and experienced many cycles of cooling and warming in the past.

itsnotnicetofoolwithmothernature said...

Only God has the answers my Children.

Ice ages come and go.

So did Dino's, so will we....

It's useless to resist mother nature.

We are all doomed..... Deal with it!

Anonymous said...

Thin wispy atmosphere, dominated/buffered by massive liquid oceans. The entire mass of the atmosphere is duplicated in the first 33 feet of our oceans. In any thermal battle between our thin whispy atmopshere and our oceans, I'm putting my money on our oceans. Within ten feet of the ocean/atmopshere interface, there is alot of ocean and a little atmopshere.

It's the Sun, folks. CO2 is a rider, not a driver. It is along for the ride, period.

Where is the increased temperatures at elevation(ie, in weather ballon and satellite sounder data)predicted by 'inreased greenhouse effect' theory--whether caused by H20 or CO2? Nope. Mainly at the surface--consistant with a solar variability effect, not an 'increased greenhouse effect.'

NASA quietly announced 'accelerated polar ice cap metling on Mars(ironically, of frozen CO2.) What the Cargo Cult scientists would have us believe: this obvious solar effect(Mars has no molten core, it's a rock), is bypassing earth and its 'anthropomorphic warming' and jumping straight to Mars.

Scary squiggles in Northern Ice cap record...not so scary squiggles in Souther Ice cap record. In fact, record coverage. If the effect is solar based, then exactly what we should expect(differences in Northern/SOuthern experience), given the fact that the earth's orbit around the Sun is eccentric. Winter freezing or Summer melting? Which is more important a factor? Pick a number, take a guess. Or, invent a magical form of Maxwell's Demon parked at the Equator(and ignore all those inconvenient water vapor images.)

Hurry, while we still have a chance to scare the kids with this 'socio-political' science.

Take science by the throat, indeed. Soft science.

Joe Ignorant said...

I'm trying to separate out the issues.

Was some CO2 was part of the original atmosphere of the earth? (I believe this is true, but am no expert, and would have to know more about the formation of the primordial atmosphere. I believe CO2 is emitted by volcanic action. Any "original" CO2 might be exchanged between the oceans and the atmosphere, but that would be a response/feedback to temperature changes sparked by other causes/forces.)

Would there be a Carbon cycle if organic processes were factored out?
(I believe there would be. CO2 in the atmosphere - combined with rain? - interacts with minerals and metals in exposed rock as part of the weathering process. These carbonates are washed into the oceans. Tectonic movements push them into the earth's mantle. Volcanic actions spews it back into the atmosphere.)

Can CO2 produced by human activity be factored out from CO2 produced by other organic processes? (This has to be self evident. Photosynthesis can take CO2 out of the atmosphere. Some of this is released again when plant organisms die. Others became fossilized in petroleum or natural gas. Marine life used carbonates from the ocean - some from eroded mountaintops - to build shells and skeletons, some of which become fossilized in petroleum or natural gas).

To what extent is non human generated CO2 a response/feedback to climate change? (It would have to be a feedback, but I'm not sure how that works. A warming climate might cause the oceans to release more CO2 into the atmosphere, but warmer temperatures might cause more plant growth - which might sequester much of this newly released CO2 ???)

To what extent is CO2 released by human activity a force for climate change?

And if the burning of fossil fuels is forcing climate change, to what extent can we rely on other other responses (negative feedbacks) to counter its effects?

My understanding is that our current science cannot account for observed global warming without recourse to human activity (deforestation, burning of fossil fuels, and production of methane from agricultural activity).

My understanding is that, when CO2 produced by human activity is factored in, then the climate models used by scientists can account for current trends in global warming.

Joe Very Ignorant said...

I think the point is that humans (and maybe the entire life process of the planet) is not really affecting the amount of water in the water cycle.

What's changing is the quantities of other Greenhouse Gases like Methane and Carbon Dioxide.

It's the human contribution to rising CO2 levels which is driving much of the global warming debate.

Anonymous said...

Atmospheric scientists cannot tell if it going to rain on Friday. Global what?

reduce water usage said...

Water vapour is indeed the most dominant greenhouse gas. The radiative forcing for water is around 75 W/m2 while carbon dioxide contributes 32 W/m2 (Kiehl 1997). Water vapour is also the dominant positive feedback in our climate system and a major reason why temperature is so sensitive to changes in CO2.

Unlike external forcings such as CO2 which can be added to the atmosphere, the level of water vapour in the atmosphere is a function of temperature. Water vapour is brought into the atmosphere via evaporation - the rate depends on the ocean and air temperature and is governed by the Clausius-Clapeyron relation.

If extra water is added to the atmosphere, it condenses and falls as rain or snow within a week or two. Similarly, if somehow moisture was sucked out of the atmosphere, evaporation would restore water vapour levels to 'normal levels' in short time.

Great post!

Anonymous said...

Burn fossil fuel and what do you get, CO2 and ????? yes water vapour.....!!!!

If CO2 is not dominant GHG then what should we be concentrating on really coming out of the tailpipes of our power stations and cars ?

The answer may be in the question, what a fascinating thread.

Rockbiter said...

Wow...what a spin. Water vapor stays in the atmosphere for a week? So, what you're saying is that water vapor only evaporates one week? Yes, it condenses as rain, but what I seem to remember as a CHILD (even before the global warming hoax -- its a hoax in that sheeple like you say that it's all man-made)is that it's a cycle -- water on the ground or in bodies of water is heated, then evaporates into the air, then cools and condenses as rain, then falls to the ground, then is heated up, then evaporates, etc. Does it condense at the same time, giving us rain everywhere at once, leaving us with NO water vapor in the air, at least until it evaporates again the following week? Water vapor is ALWAYS in the air, and there is more of it in the air than CO2, and it DOES warm the earth through its blanketing effect. And, yes, CO2 does come down with the rainfall, as it's very soluble in water -- ever heard of limestone? Ever heard of all of the carbon locked up in the oceans? While we're at it, how do you explain warm periods in the past? Did we somehow send all of our automobiles and CO2-bellowing factories in a time machine back to those eras simply to warm up the earth? Climate change has ALWAYS been around -- we go from ice ages to warm ages (sometimes ice-free!), at least 20 times in the last few billion years. Get your facts straight instead of trying to push your political agenda with junk science and hysteria.

Reality_Check said...

This discussion boils down to one thing. When you are speaking about predicting global warming over the next 10 to 100 years is water vapor an independent variable ( called a forcer by some ) or is it a dependent variable ( called feedback by some ).

In order to be a dependent variable there must exist an equation which defines the value of water vapor in terms of other variables in the global warming model.

This is very important to those defending any particular global warming prediction because if water vapor can be defined as a dependent variable of say CO2 in combination with other variables it WATER VAPOR, AS AN INDEPENDENT VARIABLE, CAN BE IGNORED when considering what effect say Carbon Dioxide or Methane or Ozone has on Global warming.

In mathematics and computer modeling in order to make a variable dependent in terms of another or several others you must have an equation to do that.

Most global warming models do have A SET OF EQUATIONS which attempt to calculate how much Water Vapor is in the Atmosphere at any one time; however, those folks promoting the accuracy of long term global warming predictions try very, very hard not to tell you what those equations they are.

To define water vapor in the atmosphere as dependent you must define mathematically how it get's there and how it returns to earth. There is another name for that set of equations - it is called a global computer model which predicts future weather.

The most accurate weather models in the world use arrays of the fastest computers in the world to predict accurately out maybe ten days. Accurate prediction to within one, two or three degrees pushing out over a year are still a dream.

Yes water vapor is not an independent variable ( not a forcer ) if, and only if, you believe they have the ability to accurately predict the weather to within 2 or 3 degrees 10 years from now and 100 years from now.

Toni said...

Tut, tut, tut...

All I read here is the chatter of overblown egoes, incapable of civilised debate without descending into point-sscoring.

That alone persuades me this is not the forum for serious debate...
Anoymous et Al... Grow up!

Toni said...

PS Those who have the least to say mostly say it at length!

Rmoen said...

The article and much of the discussion misses an important point -- CLOUDS. High clouds trap heat. Low clouds reflect heat. Clouds are made of water vapor.

Ed said...

Real science is in agreement that global warming is caused mostly by water vapor and to a much lesser extent by carbon dioxide. Only political science still claims that carbon dioxide is the problem.
The rising sea levels are also caused mostly by water. Many areas of the world have drilled wells in reservoirs where the water has been for hundreds of years. The many billions of gallons of depleted water have lowered the level of these reservoirs. This water is used mostly for agriculture, quickly evaporates, and within a month or so ends up in the ocean, raising the level.
All agriculture irrigation water, even comes is from rivers, is the major cause of global warming. The many millions of irrigated acres greatly increase worldwide evaporation, increasing the greenhouse effect. Even though this water eventually percolates out of the air, it is constantly being replaced by man-made irrigation. The result is a permanent increase over “normal levels” of water vapor in the air and a hotter climate on the earth.
The percent of water vapor in the air varies from fractional to over four percent. It averages about two and a half percent which in scientific terms is written as 25,000 parts per million. Comparing this number with the 360 parts per million of carbon dioxide in the air and you easily see that there is no comparison. Basic theory, observations and climate models all show the increase in water vapor of around 3 to 4% cause 1 degree Fahrenheit warming of the lower atmosphere.
Clouds should also be included in the water vapor numbers. Clouds cause much of the green house effect, and the higher the water vapor level, the more clouds. In fact, when you add the effect of the water vapor with the clouds, they combine to cause about 95 percent of the earth’s greenhouse effect. The remaining 5 percent is due to carbon dioxide, methane, ozone, nitrous oxide and CFCs.
So what is this cap and trade thing the political scientists are pushing. It is really a tax on everyone that ends up in the pockets of these politicians as bribes, pork barrel and just plane corruption. It won’t do anything for the environment but is just another grab for power and money at the expense of normal people.

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