On (1):... Correct. (1) And even when its concentration was almost 1000 times higher it did not cause "steam death." ...
(2) Really? A cloud covered planet would absorb more total energy? Can you think of any reason that might be an erroneous assumption?
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.We must agree to dis agree, but I will respond to this part of your post.
The authors themselves admit (Bottom of page 475.) and now red text in my post 133: (1) they made that constant 200K temperature thick layer next to Earth surface assumption to make the calculation affordable with the computers they had back when it was done (before 1986) AND
(2) They note that the prior calculation efforts which did try to work thru the radiative / convective structure of the lower atmosphere blew up - had unlimited temperature increase.
According to google that paper has 308 citations.It is also suggestive of error that no one seems to be quoting them that I can find. Perhaps that is just my lack so searching skills. Do you know of any recent published papers that cite them with approval?
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, assuming they are, is that their 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.
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:...
(Albedo) 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.
http://www.columbia.edu/~jeh1/mailings/2013/20130415_Exaggerations.pdf said:We use the Russell model in our paper to show that the tropopause rises in response to the global warming that occurs with larger and larger CO2 amounts (Fig. 7 in our paper4), and cloud cover decreases with increasing CO2. In consequence climate sensitivity initially increases as CO2 increases, consistent with the upturn of sensitivity found in more complex global climate models11.
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 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.
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)
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.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. ...
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.And no one has confidently proven that warming will not stop dead next year and then return to the 1850 average. ...
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.Another reason to think it is false is that water vapor is the most effective green house gas.
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.
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.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. ...
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.)
If upper atmosphere temperatures rise we radiate more heat, thus cooling the planet.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.
Are you admitting that the paper was correct and it was your interpretation of it that was flawed?
No, and No. In earlier post you said: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?
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.http://www.columbia.edu/~jeh1/mailings/2013/20130415_Exaggerations.pdf said:The concept of a runaway greenhouse effect was introduced (12) by considering a highly idealized situation with specified troposphere-stratosphere atmospheric structure, a simple approximation for atmospheric radiation, and no inclusion of how clouds might change as climate changes, as is appropriate for introduction of a concept. More recent studies (13) relax some of the idealizations and are sufficient to show that Earth is not now near a runaway situation, but ...the studies do not provide a picture of where Earth is headed if all fossil fuels are burned.
An alternative promising approach is to employ the fundamental equations for atmospheric structure and motions, i.e., the conservation equations for energy, momentum, mass, and water, and the ideal gas law. These equations form the core of atmospheric general circulation models and global climate models. However, today's global models generally contain representations of so many additional physical processes that the models are difficult to use for investigations of extreme climatic situations, because invariably some approximations in the scores of equations become invalid in extreme climates.
In contrast, my long-term colleague Gary Russell has developed a global model that solves the fundamental equations with the minimum additional physics needed to investigate climate sensitivity over the full range from snowball Earth to a hothouse uninhabitable planet. The additional physics includes accurate spectral dependence of solar and thermal radiation, convection, and clouds. Although the precision of the results depends on the representation of clouds, we suggest that the simple prescription employed is likely to correctly capture essence of cloud change in response to climate change.
We use the Russell model in our paper to show that the tropopause rises in response to the global warming that occurs with larger and larger CO2 amounts Fig. 7 in our paper (4), and cloud cover decreases with increasing CO2. In consequence climate sensitivity initially increases as CO2 increases, consistent with the upturn of sensitivity found in more complex global climate models. (11) With the more realistic physics in the Russell model the runaway water vapor feedback that exists with idealized concepts (12) does not occur. ...
One implication is that if we should "succeed" in digging up and burning all fossil fuels, some parts of the planet would become literally uninhabitable, with some time in the year having wet bulb temperature exceeding 35°C. At such temperatures, for reasons of physiology and physics, humans cannot survive, …
The picture that emerges for Earth sometime in the distant future, if we should dig up and burn every fossil fuel, is thus consistent with that depicted in "Storms" -- an ice-free Antarctica and a desolate planet without human inhabitants. … At least one sentence in "Storms" will need to be corrected in the next edition: even with burning of all fossil fuels the tropical ocean does not "boil". But it is not an exaggeration to suggest, based on best available scientific evidence, that burning all fossil fuels could result in the planet being not only ice-free but human-free.
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 will this one) or give just the post number, which I have written on paper.
Here's one for our member andy1033. Since he believes governments have "secret underground labs" to do things to people, including mind control, he will naturally believe this is part of their plan in action.
http://www.nbcnews.com/science/myst...y-around-world-6C10760872?lite&lite=obnetwork
And quite naturally (for him), he'll simply ignore those cases where the source of the hum was actually found. Heh-heh-heh! (grin)
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.*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.
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.
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.Good, you're backing away from that; a good move.
What I am "backing away from" is the suggestion that it might be possible for the oceans to boil . . .
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.