Addendum There were some parts of my previous post that could perhaps have been clearer. I'll clarify these later.
On (1): I don't suggest that CH4 can do the "heavy lifting" as it too will block all it can and there will still be IR escaping from Earth's surface. H2O is a polar molecule and can radiate or absorb almost any IR wave lenths - A rotating permanent dipole radiates with spin rate decreases and speeds up to absorb IR. The main role of the CO2 is to release CH4 more rapidly than it is destroyed; The main role of CH4 is to increase the water vapor in the air which can do the "heavy lifting." But of course the CO2 is also helping make the air warmer to hold more water vapor. Probably the reason why floods are more frequent now (and winter snows deeper), assuming they are, is that there is more ocean evaporation with the greater air temperature that is now mainly due to the increasing CO2 concentrations. I.e. CO2 is still blocking more IR escape than CH4 is, but CH4 is catching up and will pass CO2, but I don't know how many decades before CH4 dominates the CO2. On (2): Clouds are small water drops that mainly refract and scatter, but absorb little. They are NOT water vapor, but do indicate there is saturated water vapor near them. The net effect of clouds is complex. What their net effect on IR escape rate from Earth surface is generally to slow it - certainly that is the case during the night. During the day, I think the net effct depends on altitude, but am not sure. Not all agree what effect the clouds have and to some extent it depends on the size of the water drops and whether or not the cloud is ice crystals. I once knew more - about the Mie scattering function vs. wave length - it gets very complex for wavelenths near the droplet diameter.
BillyT, It is good to recall my thread earlier about Stephen Hawking's comparisons between the Earth's atmosphere and that of Venus'. It may interest readers to peruse the following link, whose abstract summarizes neatly what you said about the magnitude of warming being as great in magnitude as the "largest global changes" in the past 65 million years, but "orders of magnitude" greater in rate of change: http://www.sciencemag.org/content/341/6145/486 Also interesting is an alternative viewpoint given by James Hansen, who writes that the oceans may not necessarily boil, but may come close with temperatures that cannot be tolerated by the human body even at rest: http://www.columbia.edu/~jeh1/mailings/2013/20130415_Exaggerations.pdf
That was one of the parts that I was referring to in my addendum. When I re-read it I realized that what I had communicated wasn't quite what I had intended communicate. I note you've avoided the two stronger points: Why should the top of the terrestrial stratosphere (200k in the paper) be hotter than the top of the venusian stratosphere (250k obsv) Why should they examine pressures greater than 270 bar when getting that high involves the total evaporation of earths ocean and it's already higher than venusian surface pressure (90 bar). According to google that paper has 308 citations. In the first five pages of results I found one that discussing criteria for habitability that derived numbers relating to the oneer edge of the habitable zone using that pape, and then proceeding to discusss whether or not Gl 581 would be a good target for TPF or Darwin. That paper dates fcrom 2007 and was accepted for publication in "Astronomy and Astrophysics". The second paper dates from 2009 and also uses the paper you're dismissing as fundamentally flawed to set habitable zone constraints and the delivery of water to planets in the habital zone. This paper was also accepted for publication. 308 ctations including positive citations in the last 5 years. Face it Billy T it's not the paper that's wrong, it's your interpretation of it, for the reasons I have already pointed out.
In the past we have had far higher concentrations of both CO2 and CH4 - and all the water we do now. (Probably more, actually, due to constant dissociation of water in the atmosphere.) We didn't get the "steam death" then. So unless you propose some new additional mechanism to get a massive increase in retained heat beyond those three it's going to be a hard sell. Link to albedo chart: http://en.wikipedia.org/wiki/File:Albedo-e_hg.svg Summary: Snow 40-85% Clouds 35-75% Water 5-8% Land 10-43% More moisture in our atmosphere = more clouds. More clouds = lower albedo. There are exceptions but they are exceptions, not the rule. Consider this. We get about 1300 watts/sq m in direct sunlight hitting the planet. ALL our climate change gases have added up to a maximum of about 3.5 watts more per meter retained; a small but measurable percentage of the total. Changing from open ocean to cloud changes the incoming energy number by ~600 watts per square meter. That will dominate.
Yes to most of your post, but there is no reason to think that cloud cover fraction will increase - but the volume of rain falling surely will. Actually the cloud cover fraction is expected to DECREASE as CO2 concentrations increase: More important, I think, is the melting snow and ice with very high albedo changing to water's very low albedo. (Also when Greenland is ice free, the ocean surface will be greater - some of land's 10-43% albedo will become water's 5-8%) Also note the oceans do not need to boil to kill everyone. If the "web bulb" temperature goes to 40C for a few weeks most, if not all*, will die. Humans, with body temperature of 37C, even just resting or sleeping, need to dump ~100 watts to their environment. They can not cool by evaporation in a 40C wet bulb environment. Even now, "heat waves" kill the weaker people. Again, I am not predicting earth will switch to its hot stable state - only discussing that it may be possible, until confidently proven to be impossible, (which no one has yet done, IMHO) so that people understand we are flirting with extinction of humanity and most other creatures**, so we should switch to solar energy ASAP rather than continue to burn fossil fuels. Brazil*** has largely done this and in post 1436 of the "Apocalypse Soon" I show how the entire world could switch to a sugar cane based energy system in a decade or so. - It will take that long to replace / convert gasoline powered cars. * The wealthy, can afford air condition, but that just speeds the killing of others and is not sustainable in the long run. ** Birds, have higher body temperatures than humans as to fly, which requires high power levels, they need higher metabolism rates. They will become extinct first, except for ducks and a few others that can "water cool." *** Less than 5% of Brazil's electrical energy comes from fossil fuels. ~85% is hydro-power, more than 5% is thermal steam made by burning the sugar cane after it has been crushed and supplied the distillation of alcohol heat requirements, wind and solar PV make a few percent each and Brazil's one nuclear site makes about 1%. The sugar cane alcohol not only fuels Brazilian cars but also now Braskem is making 400,000 TONNES of plastic annually from sugar cane, not oil, at lower cost than oil at $90/ brl or greater.
One of two things MUST happen. If the temperature of the upper atmosphere remains the same, more moisture will result in more clouds, since the normal processes of adiabatic cooling will result in more water condensing into clouds as it rises. This will tend to reduce albedo of the planet. If the temperature of the upper atmosphere rises, then you can have an increase in moisture without an increase in clouds. In that case total emissivity of the planet goes up commensurate with the increase in upper atmosphere temperature. In both cases, increasing water vapor will tend to cool the planet. Agreed. In some cases, agreed. This is due to a drier atmosphere. (Hotter temps = less water retained in soil = drier land = drier air overall.) Agreed. However this is happening at the poles where the amount of radiation received is already very low due to the oblique angle of the sun coming in. A square mile of cloud at the equator has a MUCH larger effect than a square mile of ice at either pole. Agreed. Fortunately even the worst case IPCC climate models do not predict anything close to that. And no one has confidently proven that warming will not stop dead next year and then return to the 1850 average. So until then, no need to do anything about climate change. (No I don't really think that, but it makes as much sense as your statement above.)
I don't now if that last sentence is correct or not. I just defer to the experts who seem to agree that more CO2 in the air means fewer clouds, but admit that is very counter intutitive. Must be some complex dynmics, hard to simply understand. I agree that clouds tend to increase the albedo, so with less of them the albedo, we agree, decreases - i.e. more solar energy is absorbed and less reflected back into space. Thus I tend to think your last sentence is false if CO2 in air is increasing as it is annually at 2ppm and slightly increasing. Another reason to think it is false is that water vapor is the most effective green house gas. I don't recall the numbers, but think each H2O molecule added would have more effect than ten CO2 molecules added, not only because H2O has a stronger effect but also because CO2 is already near it max IR blocking capacity, while water vapor is far from that. I suspect that the last sentence just reflects your earlier false statement that there would be MORE clouds with more water vapor in the air. Another fact to consider if there is more water vapor in the air: It will be harder for humans to keep cool by perspiring - human extinction is easier to achieve with global warming. That is a very weak, if not completely false analogy. No one has offered any even slightly plausible reason why or how global warmimg could "stop dead next year and then return to the 1850 average." but how the Earth could heat enough to kill all humans has very well described, physically plausible, mechanisms. In fact my concern is it may be in the process of doing just that.
It is only a greenhouse gas if it is not condensing. If it is (i.e. clouds) it cools the planet. Thus you need to postulate a scenario where 1) water vapor increases, 2) clouds do not and 3) upper atmosphere temperatures do not. Since those requirements are contradictory, I'm not too worried. EVERYTHING ELSE BEING EQUAL there would be. Climate change will tend to make land areas warmer. This will decrease relative humidity. Thus overall relative humidity will go down, at least in places where people live (i.e. land.)
I don't intend to argue with you. I already said I defer to the experts and admit it is very counter intuitive that increasing CO2 DECREASES the cloud coverage but as the air warms it can hold more water vapor without saturation. - Perhaps that is why there are less clouds. I.e. the warmer air "evaporates" the water droplets we call clouds. I don't know what your point 3 (upper atmosphere temperatures do not) is stating or why. You did agree that with greater water vapor in the air there would be more rain, yet now you say the land would be more dry - that seems self contradictory to me. The relative humidity INCREASES in the rain. Air above recently rain-wet soil tends to have INCREASED relative humidity too. Areas with little rain, called deserts, is where the relative humidity tends to be low. BTW I don't need to postulate anything - I just accept the expert's POV that with CO2 increasing there are less clouds and thus a lower Earth albedo and thus more solar heating of earth - I.e. another positive feed back system, but with, as we agreed, more rain. Possibly the "more rain" come at night as the air temperature cools? In Sao Paulo there is often a very fine rain, called "Grazola" or something like that but probably spelled differently than I have. It is so tiny drops that you don't get wet - body heat evaporates it as fast as it falls. Point is that clouds are not necessary for rain. I think the only requirement for rain is water vapor saturated air. We have a lot of air pollution. Perhaps microscopic air particle nucleate fine drops with no clouds.
So Billy, I notice that you're ignoring me (again). Does that mean that you concede the point? Are you admitting that the paper was correct and it was your interpretation of it that was flawed?
If upper atmosphere temperatures rise we radiate more heat, thus cooling the planet. If upper atmosphere temperatures do not rise it is very difficult to come up with a scenario where more water vapor does not mean more clouds. Overall, increasing temperature on land decreases rain on land. Water is evaporated more rapidly, allowing more complete drying after rains. Dry land then produces no water for storm formation. However, increasing temperatures on water increase rain over the water, because evaporation is more rapid - and the ocean will not run out of water. Storms that transition between the two (like hurricanes) will tend to bring more water overall to land. But in more land locked areas (Midwest, Soutwest) the trend will be drier.
To further illustrate my point, I'm going to quote the part Billy T has referred to repeatedly, however, I will place it in context. The bolded portion is the portion that Billy T is effectively cherry picking and basing his claim that the assumptions force the conclusions: (d) Thermal Structure The present model is similar to the model of Pollack (1971) in that the temperature structure of the atmosphere was assumed rather than calculated. This assumption is motivated primarily by expedience. As discussed by KPA, the Newton-Raphson iteration procedure used in their steady-state radiative-convective model fails to converge at high surface temperatures (>110 °C) because of strong coupling between surface temperature and pressure. This problem can apparently be overcome by using a model that adds or subtracts grid points as the surface pressure changes (Y. Abe, private communication, 1987). The present model, on the other hand, is much cheaper to run. Fortunately, it can also be demonstrated (see below) that this assumption results in no significant loss of generality for the results. By contrast, KPA, Waterson et al. (1984) and Vardavas and Carver (1985) all calculated temperature profiles self-consistently. KPA is an abbreviation Kasting uses to refer back to a previous paper that he co-authored: Response of Earth's atmosphere to increases in solar flux and implications for loss of water from Venus. I can not currently access it as it is behind a pay-wall. So while Billy T is correct in that they assumed the stratosphere of venus was isothermic, the temperature they assigned to the stratosphere is not an unreasonable one (based on observations of venus) and the fact that the model fails to converge at high temperatures appears to be a resolution issue rather than a reflection of reality as Billy T would have us believe. That's without pointing out the fact that Kasting, at least, seems to believe that his assumptions are reasonable in light of other papers on the matter.
No, and No. In earlier post you said: "How magnaminous of you. Letting readers wade through around 700 posts to find the one post you're referring to." I was some what confused and offended as I gave the specific post number and thread name. Exactly as I did when suggesting that the reader look at my post 1436 telling how it was feasible for the entire world to switch to a sugar cane energy based system. When writing a post I can not easily go into another thread to copy the link without losing what I have written so I either post the incompleted post (as I first did this one) or give just the post number and thread , which I have written on paper. Based on the following (and other recent, more accurate and studies, not making the two false simplifying assumption of your link, and including several important aspects, like cloud effects, which your link does not) I now think it is 99% certain that the oceans can not boil, although some others including a widely respected NOAA scientist / climate expert / (James Hansen) also gave condition (burn all the economically available fossil fuels in the next few centuries) in which the models then used (and much more complete and accurate than the old model of your link) did predict the oceans would boil. None-the-less the extinction of humanity and most life forms seems likely according to the latest and most complete models. The following is Hansen's 15 April 2013 POV: Thus my efforts to show it is essential to switch, as outlined in post 1436 of the "Apocalypse Soon" thread to a non-fossil fuel energy system ASAP will continue, but I will no longer (as Hansen has also stopped), suggest that the oceans may boil. - Only that the present fossil fuel based energy system is likely to lead to human extinction, if not greatly suplimented with some solar (or nuclear) energy system. BTW, "storms" refers to Hansen's book Storms of our Grandchildren written several years ago, when he too (falsely) expected the oceans to boil.
So then address the rest of the post. Discuss the point. Ignoring arguments against your hypothesis and then raising the same point in thread after thread after thread is, according to Fraggle Rocker at least, intellectual dishonesty. Yes, you told them which thread it was, and what post it was, that's great The thread is furrently and 1541 posts. Readers would have to go back through 400 posts (oops, my bad) to find the specific post you're referring to. I run at 20 posts per page and I had to go back to page 59 of a 78 page thread to track down the posts in question. The simple fact is that your objections are unfounded and based on misunderstandings of the paper.
A Common source for low level Hum's can be found at Landfill Sites, Oil Wells, Mines and Silo Storage tanks (Chemical/Fuel). The usage of Flaring placed into a "Shrouded" environment to conceal the flame can cause a hum. Usually when the flares are fitted it's suggested to also place mounds of earth to aid in projecting the sound up rather than out and placing dampner's on the Shroud itself. The sound is made from Gas being burnt at Mach speed and then amplified by the "Shrouding" echoing it. Flares are often used to reduce both the pollution of migrating gases and lower the chances of build up that could result in explosions. Migrating gases can cause most of the underlining conditions mentioned e.g. "Sufferers complain of headaches, nausea, dizziness, nosebleeds..." Incidentally in the UK, it's the EPA that measures the level of audible sound outputted from a Flare. There is actually a limitation on the level allowed, should you hear a low hum then it's best to contact them and identify where you are so they can work out what nearby might be causing it. Alternatively the local councils might also be able to help. (The US EPA also measures that I believe, although I'll have to confirm that) As for Climate change, don't even get me started on how Open-Pipe flares aren't efficient due to their fixed designs which in turn leads to pollutants that can actually be more harmful than just the gas being Vented.
First the claim that one needs to look at 700 or 400 posts to find and read a post with given post number is NONSENSE.* Secondly you posted before I completed my post, in which Hansen and others tell several faults with your link specifically (and others work from that era). I don't need or intend to discuss your link's flaws more, as it is a very crude early effort. Imagine assuming wide layer of constant 200K air next to the surface and that the surface pressure is some fixed arbitrary constant despite ocean water evaporating and changing the atmospheric pressure and density, totally ignoring cloud effects, which even the more recent and vastly superior computer models have trouble with accurately modeling plus totally ignoring the positive feed back interaction between CO2 release rates, CH4 and it destruction rates, and I think H2O and the other GHGs decomposing in the UV. If that is not enough "discussion" for you, I'm sorry but will not give more reasons why after more than an hour of careful study of your link, I totally reject its conclusion, as the more modern studies have done too. *PS I did my undergraduate work at Cornell, which is a "land grant" college and thus ROTC was required of all males, in my era. I did learn one thing in the class, when told how to quickly zero a mortar shell on target: Fire first very long then intentionally some what short. Don't be silly and just incrementally change the range setting. I.e. in your case, jump twenty pages, note the post number and fall back 10 pages if you have gone too far. With modest intelligence you can then guess the page number the post you seek is on with no more than one page error. That ROTC grade was included in my GPA and I was dangerously close to 85 below which I would lose my full needs scholarship and need to go home (as I was very poor - washed dishes for my meals etc.). The ROTC instructor offered a grade of 100 to anyone who could take apart the M1, blind folded, naming each piece while doing so and re-assemble it in 60 seconds, total. I borrowed one and practiced - I got the 100 grade. Main trick is to have a definite place on the table where your always place the pieces as you take it apart, so no groping is needed during the reassembly. The ROTC course was only one credit hour, but it pulled my GPA up to almost 90. (I was not in as much danger as I feared.) My experimental five-year program in "Engineering Physics" was the toughest Cornell has ever offered, with many graduate level classes. So tough that more than half my class mates transferred out to easier four-year programs, like EE, ME or CE and soon after I graduated Cornell terminated the program. It was 5 years as it met every requirement of both the engineering and the liberal arts divisions.
Good, you're backing away from that; a good move. Now your challenge (should you decide to accept it) is to demonstrate why you are right and why the IPCC - who has spent decades and hundreds of millions studying this exact topic - is wrong. Because they HAVE taken clathrate releases, anthropogenic methane etc into account in their models.
What I am "backing away from" is the suggestion that it might be possible for the oceans to boil as some models of a few year ago had also suggested. I never claimed, and frequently stated that I was not claiming, that the oceans would boil, usually in the form that I was not predicting earth would switch to its hot stable state. My impression is that the IPCC has and is still making significant changes in its expectations, and gives several different ranges. Can you give a link to their latest and most probable POV of our future? Thanks.
Right, and that's what I was saying was a good move. Sure. Link to prediction ranges from the 2007 assessment below. http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg3/081.htm Basically they posit four scenarios - A1, A2, B1, and B2 - with different assumptions for cultural change and efforts towards sustainability. These scenarios result in a year 2100 temperature change of +1.1 to +2.9C (best case) to +1.4 to +6.4C (worst case.)
