How about people in america stop driving 5.0litre cars on a regular basis? Driving 5 miles less each week in the uk is hardly going to amount to anything. Its these stupid little things that annoy me a great deal.

The fact is if its such a big problem, then do some big things to solve it. Not these stupid things like drive 5 miles less. Drive 5 miles less forever? Will it go up to 10? 20? Drive 50 miles less? Where does it stop? It doesnt provide a long term solution. Therefore its laughable.

Ive also heard that actually if the atmosphere becomes that bad they can fire rockets (ridiclous I know, but so a scientist said) into the atmosphere and balance it out. Sorry I dont know what was in the rockets, it sounded insane. But so does driving 5 miles less.

actual heat loss is going to be the difference between the heat radiated (and evaporative cooling sweat) and heat absorbed by radiative means.

as stated above, stefan’s law is an integration of angle and wavelength of planck’s law.

I don’t know what you mean by seeing telemetry. also, radiative transfer is the only science of substance that those politicians can legitimately claim is fairly well understood.

if its true we generate optimum 100wpsm at 15 C, it’s logical that radiation exiting is a great deal less than 50wpsm. All things earthly would be in the 12-16 micron range, whilst S-B overestimates it 10 times.

Simply stated: Human heat loss is 75-100wpsm. Earth heat loss is much less, otherwise, we’d see it via telemetry, which covers all the *assumed* wavelengths that our venerable climate officials say it is

I’ve just posted on the basal metabolic rate of a human, (in the “A borehole in Antarctica produces evidence of sudden warming” thread) which is an average 85wpsm – equipment calibrated on the SB constant records a higher wattage of emission for normal temperature matter, yet thermal imaging technology records a human at a greater radiate magnitude than normal temperature matter.

I’m not sure what you mean by an s curve or how it applies to sb. sb was first empirical in origins but it is derivable from plank’s equation, integrated over angle and wavelength. emissivity as a single number is merely an engineering approximation but within limits, it works well. There are many commercial products that measure temperature by analyzing the IR signature of normal matter. As for the Sun, it essentially radiates a continuum from a gas that we would consider is a rather good vacuum at around 6000k.

One can get a glimpse of positive or negative feedback by the average sensitivity of the atmosphere based upon how much increase in temperature the average Earth value is over that of a blackbody with the same albedo (33 deg K rise for 150 to 160 W/m^2 power gives a response of around 0.22 K rise per W/m^2. One can also get a glimpse of this value, at least for clear skies, by taking the increase in surface temperature required to overcome an increase of 1W/m^2 in absorption by an increase in a little over 1 W/m^2 in emissions using stefan’s law. In clear skies, one has 390-150 = 240 w/m^2 escaping or a fraction of emitted 240/390 = 0.62. That indicates 1/0.62 = 1.6w/m^2 results in 1w/m^2 leaving the atmosphere. For 288.2 K, that means the 391.2w/m^2 would have to increase to 392.8 in order for balance to be restored, ignoring convection. This corresponds to 288.5 kelvins temperature or 0.3 Kelvins increase in temperature without convection. Note that convection at the surface is close to 100 w/m^2 but reduces to essentially nothing at the tropopause. It is what is needed to overcome all that water vapor located near the surface that is almost nonexistent way high up. Any increase in surface temperature creates an increase in convection that is a negative feedback. The expectation of a large water vapor feedback not only ignores the watervapor cycle but it must be based on a very paltry variation.

The comment you say you don’t understand simply states that the negative feedback is actually what is referred to as a setpoint control using negative feedback. The statement of feedback is not actually correct conceptually.

Assuming an absence of negative feedback is to presume that convection doesn’t occur or isn’t a function of temperature differential or change. You’ll note that the above examples shows the average effect per w/m^2 of 0.22 is less than the 0.3 kelvin rise of the differential temperature necessary for radiative only. It also precludes the presence of some sort of net positive feedback other than more watervapor.

As for climate models showing anything actually related to the real world, they remind me of the old punch card sorting equipment they used to have in the old carnival sideshows billed as computer based fortune telling.

the cloud feedback is simple to explain with a minimal bit of thought. Clouds are high albedo, liquid water at low angle of incidence (wrt to the normal) is tremendously low and makes up most of the surface where there is a low incidence angle. When one develops a high albedo surface condition, such as fresh snow, then one has a totally short circuited situation where the setpoint system no longer functions at all because there’s no difference with and without the clouds – not to mention the liklihood that there is far less h2o vapor present so the actual ghg absorption drops as well so a double whammy of higher albedo and lower ghg absorption occurs. Something like massive volcanic erruptions and/or asteroid impacts and/or massive increase in cloud cover perhaps due to cosmic radiation variations and/or gamma ray burst effects could, especially when combined with milenkovich orbital effects could trigger such a condition and such conditions as a glaciation period could potentially last until precipitation dropped below the sublimation rate and/or the ice/snow cover became very dirty with much lower albedo and/or some event variation with warming (rather than cooling) effects occurred.

Some ofthat power is reflected in albedo and some is absorbed. It doesn’t wind up going to ground. In the tropical areas where there really is significant incoming solar, a lot of that absorbed energy goes into daytime cloud and thunderstorm formation – and the energy is high up in the atmosphere ripe to radiate out.

I’m a little confused at what you are suggesting here. If you are going to claim that this affects the final radiative balance, the argument would presumably have to be that the upper troposphere ends up warmer than the models would expect relative to the surface…and, yet, you have most people here quite insistent that the data actually shows the opposite, i.e., that the amplification in the tropical atmosphere is not occurring, or at least not the degree predicted by the models. I think that this is probably mainly a data quality issue (along with correctly taking into account the errorbars on the model predictions), but still the idea that the upper troposphere is actually significantly warmer relative to the surface than the models predict seems like a bit of a stretch!

Changing the cloud cover fraction can result in changing the balance point without changing temperatures.

I agree.

Another little tidbit there is the implicit suggestion that there is a strong feedback mechanism (actually a setpoint control mechanism using negative feedback) that determines the average cloud cover because otherwise there would be no common average temperature as it would randomly drift around.

I don’t understand this claim at all. Actually, I am not really sure what you are saying exactly anyway. However, to the extent that you think that the lack of negative feedback would cause too much change in temperatures, it seems to me that this would then be apparent in the climate models…i.e., they would exhibit too much variability in temperature relative to the observations. However, I don’t think this is actually found to be the case.

And, with a strong negative feedback mechanism from clouds, it becomes difficult to explain the ice age – interglacial cycles without proposing some very big additional forcing that is currently being left out.

one of the problems is when you start to talk about truly serious cloud cover – as in low overcast clouds rather than thin semi transparant stuff near the stratosphere that has little to no effect on albedo anyway – is that you can lose 90% + of the incoming solar power. Remember that there is more power in the SW incoming in the near IR than there is in the visible as well. Some ofthat power is reflected in albedo and some is absorbed. It doesn’t wind up going to ground. In the tropical areas where there really is significant incoming solar, a lot of that absorbed energy goes into daytime cloud and thunderstorm formation – and the energy is high up in the atmosphere ripe to radiate out.

What you can do is create a couple of linear graphs (x axis is cloud cover fraction 0-1.0) for what could be called an averaged cloud effect. No clouds results in almost 340 W/m^2 incoming while 1.0 cloud cover is around 10% of that. Outgoing can be (back of the envelope estimated) at 390 – 150 = 240w/m^2 for clear skies and then estimated for cloud tops at an altitude around freezing with radiation by stefan’s law being for near 273k. Draw the incoming and outgoing lines as it should be rather linear with surface area. Look for the intersection – it should be in the general vicinity of just over 60% or 0.6 cloud cover fraction. You should also note that the energy balance between in and out is not strictly a function of ghg absorption but rather is also a function of cloud cover fraction. Changing the cloud cover fraction can result in changing the balance point without changing temperatures. Another little tidbit there is the implicit suggestion that there is a strong feedback mechanism (actually a setpoint control mechanism using negative feedback) that determines the average cloud cover because otherwise there would be no common average temperature as it would randomly drift around. Unfortunately, it doesn’t really suggest what that mechanism is though one can infer that it is the water cycle at work – power heats surface, heat of evaporation taken into air, lighter warmer parcels rise, radiating out energy, forming clouds, dropping precipitation cooling off, dropping out h2o content, falling down due to higher density etc etc etc. – classical cycle just like what one sees inside an individual thunderstorm or rainstorm.

I gather you’ve been too busy to work your way through my post above.

Yeah…A combination of too busy and it going off into more details than I wanted to get into. My basic point was that, while cloud feedbacks are certainly a large source of uncertainty, things aren’t poised quite as sensitively to clouds as one might think very naively.

For example, I once had a person tell me that a 1% change in cloudiness would produce as much radiative forcing as doubling CO2. This was presumably obtained, sloppily from the idea that a change in albedo by 0.01…and without any change to the outgoing longwave radiation…would amount to about a 3.5 W/m^2 change. And, my point is that it is not really nearly that sensitive both because a change of 0.01 in albedo would amount to about a 5%, not 1% change in the albedo due to clouds…and also that there will tend to be partly-compensating effects from clouds effects on the outgoing longwave radiation.

You seem to be suggesting by your back-of-the-envelope calculations that the value for the net radiative forcing of about -18 W/m^2 for clouds computed from the ERBE data by Ramanathan et al. may be somewhat on the low (in magnitude) side. Perhaps that is the case; I would have to look into the literature more to see what the range of current best values is. But, at any rate, for the sort of very basic qualitative point I was making, it would not make a huge difference. Clearly, it would make a difference if one wanted to get very quantitative about it.

That statement shows an awful lot more about you than it does about Jim … and not in any positive light whatsoever.

I gather you’ve been too busy to work your way through my post above.

By the way, I took the liberty of following your link to your “FreeRepublic” page (which may say something about you!) and I would note that your label of that graph as “incoming solar radiation” and your statement that “Earth radiates 160,000 times less than the sun” are both somewhat subject to misinterpretation. First, while it is true that the amount that the sun radiates per square meter of its surface is ~160,000 times the amount the earth radiates, the earth actually intercepts only a small fraction of this because by the time the radiation from the sun reaches the earth’s orbit, that radiation is spread out over a sphere of radius ~223 times the radius of the sun, which means the irradiance in W/m^2 is down by a factor of ~50,000 from what it is at the sun’s surface. And, thus your plot showing the “incoming solar radiation” is not correctly normalized if, by incoming you mean incoming to the Earth.

Of course, to a very good approximation, the amount that the Earth radiates is in fact equal to the amount of radiation that it receives (i.e., absorbs) from the sun because even with the current increases in greenhouse gases, the Earth is still only a fraction of a percent out of radiative balance relative to the amount of incoming radiation.