The central point is that the major absorbing gas in the atmosphere is water, not CO2, and although CO2 is the only other significant atmospheric absorbing gas, it is still only a minor contributor because of its relatively low concentration. The radiative absorption âcross sectionsâ for water and CO2 are so similar that their relative influence depends primarily on their relative concentrations. Indeed, although water actually absorbs more strongly, for many engineering calculations the concentrations of the two gases are added, and the mixture is treated as a single gas. In the atmosphere, the molar concentration of CO2 is in the range of 350â400 ppm. Water, on the other hand, has a very large variation but, using the â60/60â (60% relative humidity [RH] at 60 °F) value as an average, then from the American Society of Heating, Refrigerating and Air-Conditioning Engineers standard psychrometric chart, the weight ratio of water to (dry) air is ~0.0065, or roughly 10,500 ppm. Compared with CO2, this puts water, on average, at 25â30 times the (molar) concentration of the CO2, but it can range from a 1:1 ratio to >100:1. Even closer focus on water is given by solution of the SchusterâSchwarzschild equation applied to the U.S. Standard Atmosphere profiles for the variation of temperature, pressure, and air density with elevation (8). The results show that the average absorption coefficient obtained for the atmosphere closely corresponds to that for the 5.6â7.6-µm water radiation band, when water is in the concentration range 60â80% RHâon target for atmospheric conditions. The absorption coefficient is 1â2 orders of magnitude higher than the coefficient values for the CO2 bands at a concentration of 400 ppm. This would seem to eliminate CO2 and thus provide closure to that argument. This overall position can be summarized by saying that water accounts, on average, for >95% of the radiative absorption. And, because of the variation in the absorption due to water variation, anything future increases in CO2 might do, water will already have done. The common objection to this argument is that the wide fluctuations in water concentration make an averaging (for some reason) impermissible. Yet such averaging is applied without objection to global temperatures, when the actual temperature variation across the Earth from poles to equator is roughly â100 to +100 °F, and a change on the average of ±1 °F is considered major and significant. If this averaging procedure can be applied to the atmospheric temperature, it can be applied to the atmospheric water content; and if it is denied for water, it must, likewise, be denied for temperatureâin that case we donât have an identified problem! http://pubs.acs.org/subscribe/journals/ci/31/special/may01_viewpoint.html No one questions global temperature fluctuations, temperature fluctuations have been occurring on earth since the beginning of time. The question is rather they are anthropogenic in nature or not. If water vapor is ignored as it often is the conclusion becomes humans are causing global warming. However when water vapor is factor into the calculations C02 accounts for less that 4% of the total green house effect. http://www.geocraft.com/WVFossils/greenhouse_data.html
Wow, where to begin. Let's address this mechanical engineer's obviously incorrect opinions on climatology: 1) CO2's contribution is not minor due to a "low concentration" as it is one of the most efficient gases for absorbing infra-red radiation -- and has the bonus of emitting that radiation back out in a random direction. 2) The radiative absorption "cross sections" for water and CO2 are quite different -- CO2 absorbing at the peak of the IR band, and H20 absorbing less at the peak of the IR band: http://upload.wikimedia.org/wikiped...ission.png/595px-Atmospheric_Transmission.png 3) Water vapor is a greenhouse gas but is not a "forcing" gas as it rains out when in too high a concentration. And when it's raining, it's even higher! Again, the stuff falls out of the sky when in too high a concentration. Firstly the SchusterâSchwarzschild formula is called the "SchusterâSchwarzschild approximation" because it's an approximation. Secondly, water rains out. Thirdly, water vapor does a less efficient job (compared to CO2) of absorbing peak IR as shown in the graph above. Fourthly, SchusterâSchwarzschild only approximates monochromatic radiation in perfect cylinders and perfect spheres. But not of IR, which anyone who looks at the graph above can see. Not this guy, but anyone else can see. You can see how the graph of H2O dips in the middle of the infra-red spectrum. The increase in CO2 has already been proven to be from man. Look at the graph above -- CO2 is, by it's nature, an efficient absorber of infra-red energy. There is no question here. Water vapor is never ignored, not by the IPCC, not by current climate models, not by climatologists, not by anyone in the field. Yeah, if you are a mechanical engineer using a "fudge factor" approximation who doesn't understand the IR spectrum.
Actually he was born in Hawaii and raised by his grandparents who were nonpracticing Baptists and Methodists. All Christians are Christians by choice.
There are plenty more sources I can provide. "Carbon dioxide adds 12 percent to radiation trapping, which is less than the contribution from either water vapor or clouds. By itself, however, carbon dioxide is capable of trapping three times as much radiation as it actually does in the Earth's atmosphere. Freidenreich and colleagues [106] have reported the overlap of carbon dioxide and water absorption bands in the infrared region. Given the present composition of the atmosphere, the contribution to the total heating rate in the troposphere is around 5 percent from carbon dioxide and around 95 percent from water vapor." --Energy Information Administration; Official Energy Statistics from the U.S. Government http://www.eia.doe.gov/cneaf/alternate/page/environment/appd_d.html "Over 95 percent of the earthâs natural greenhouse effect is from water vapor, and about 3 percent of it is from carbon dioxide." --Dr. Patrick J. Michaels, Virginia State Climatologist and Professor of Environmental Sciences, University of Virginia http://www.geocraft.com/WVFossils/Reference_Docs/PMichaels_Jun98.pdf "The number one greenhouse gas is actually water vapor. It's something like 98 percent, by volume, of all greenhouse gases. I like the way that my colleague, Jan Veizer at the University of Ottawa, a world-renowned expert on the carbon cycle, lists the relative importance of greenhouse gases when he speaks on the topic. He points out that the number one greenhouse gas is water vapor, the number two greenhouse gas is water vapor, the number three greenhouse gas is water vapor, the number four greenhouse gas is water vapor and CO2 is a distant fifth. Of course, this list is somewhat facetious as there is only one type of water vapor. However, he lists the relative importance of greenhouse gases this was to indicate just how insignificant the tiny carbon dioxide cycle is to the water vapor cycle that it piggybacks on." --Dr. Tim Patterson, Professor of Geology-- Carleton University http://www.tcsdaily.com/article.aspx?id=010405M "The Environmental Protection Agency is seeking to classify water vapor as a pollutant, due to its central role in global warming. Because water vapor is the dominant greenhouse gas in the atmosphere, accounting for at least 90% of the Earth's natural greenhouse effect, its emission during many human activities, such as the burning of fuels, is coming under increasing scrutiny by federal regulators." http://www.ecoenquirer.com/EPA-water-vapor.htm "The most important among these 'greenhouse gases' is water vapor, which is responsible for about 96 to 99 percent of the greenhouse effect. Among the other greenhouse gases (CO2, CH4, CFCs, N2O, and O3), the most important is CO2, which contributes only 3 percent to the total greenhouse effect.11, 12 The manmade CO2 contribution to this effect may be about 0.05 to 0.25 percent.13" http://www.geocraft.com/WVFossils/Reference_Docs/sci_and_techn-glacial_expansion_03-04.pdf EPA Director of the Department of Pollutant Decrees, Ray Donaldson, said, "Back before carbon dioxide was dangerous, we simply assumed that water vapor was also benign. http://www.ecoenquirer.com/EPA-water-vapor.htm And we haven't even begun to talk about humans only account for 5% of the total CO2 in the atmosphere.
You're insane cuz after repeatedly saying that just a single year, or only a few years means nothing, you pull up numbers from the VERY recent past. Only a moron or a liar would do that and not look at the bulk of the situation. But this is exactly what you do ALSO when it regards MMGW. When asked about long term temp trends that clearly show that today is cooler than the MWP, you pull graphs from the last 500, or 50, or 25 yrs that support your position cuz they exclude that period. You avoid looking at all available data that can be agreed upon as accurate. Again, the IPCC in 1990 clearly showed the MWP, and the LIA. This is also confirmed by earth borehole measurements that also clearly show higher temps during the MWP, and lower temps during the LIA. http://www.uoguelph.ca/~rmckitri/research/McKitrick-hockeystick.pdf It is inescapable that at the very least, you must admit that at one time, the IPCC agreed that there were warmer temps during the MWP, and that to base your temp trends starting during the LIA is deceptive at best. Face it, the IPCC decided to take a political stance about using fossil fuels. So they changed their mind and the MWp and LIA disappeared. Then the hockey stick came into being, which is also flawed due to incorrect weighting of just one set of tree ring data, which when dropped from the final set as described in that pdf, resulted in a flat temp curve. It's all explained eloquently by this guy as why that data set shouldn't have been used in the first place: "I am fairly well familiar with the area where those Bristlecones were assessed. It is in a microclimate within the already quite unusual general climate at the western edge of the Great Basin. It is located on an overall range of mountains, second only to the Sierra Nevada, in which rainshadow they lie. Many of the typical rules applicable to "Mid latitude" climate do not apply there. For example, the Sierra Nevada interdict vast percentages of "straight on" moisture - e.g. that riding on cyclonic disturbances coming in on a standard Westerly. And that Westerly is often blocked by the Pacific High, during short periods during our Rainy Season and almost 100% of the time during our (late Spring - Mid to Late Fall) dry season. The seriously heavy dumps of snow come in the winter when a "Siberian Express" gets set up and the far more rare summer dumps of rain are almost entirely the result of the typical Monsoon (e.g. moisture coming up from the Gulf Of California and more rarely the Gulf of Mexico when the Pacific High retrogrades further off shore). I reckon the trees grown more when the snowpack has been more massive, again during years when the Siberian Express has been dominant. So, bottom line is, they used as a proxy trees which are an unusual species living in a highly unusual climate, where growth would not tend to follow the pattern seen in forests located in truly Continental or Maritime climates such as is the case of Gaspe and Arkansas. Let me say that using Bristlecone proxies is utterly ill advised under any normal rules of selection of proxies broadly representative of conditions affecting a broad areal distribution of flora." But it's not your fault Dave. You just don't know any better. I feel sorry for you.
case in point: Dave responds to a statement that Antarctic ice has been increasing since the 70's with an article that deals with only 3 years. By his own standards, this is irrelevant. But somehow, this standard doesn't apply to the MMGW believers.
Because he's released his birth certificate, because the director of the Hawaii Department of Health, Dr. Chiyome Fukino, stated that he personally saw and verified the birth certificate, that the Governor of Hawaii, Linda Lingle, stated that it was a valid birth certificate, and that there were birth announcements published when he was born publically announcing his birth in local newspapers. And that, as they say, is that. If that's not good enough for you there's nothing I can do for you. It's silly. Being Christian is a choice. I haven't seen any evidence that he even saw that sermon (not that I would care anyway since it's guilt-by-association, and wrong.) But let's get back on topic. What's your opinion on global warming's birth certificate?
Nobody's arguing that water vapor isn't a greenhouse gas, it is. However it is not a "forcing" gas because it rains out at increased concentrations. Now, please address my actual points.
Another example: In response to drj about cosmic rays and their effects on temp for a time scale in the hundreds of years, Dave responds by mentioning solar cycles, which have a cycle of 11 years. Again, irrelevant by Dave's standards, but it doesn't seem to apply to him.