Guest post by Bob Irvine
ABSTRACT
The Earth’s feedback response to warming is independent of the nature of the forcing that caused that warming. The question I intend to examine is whether the nature of the forcing will have a significant impact on the initial warming or the response time of the earth’s system. I looked at changes in three different types of forcing and their effect on the earth’s temperature response.
1. Changes in solar forcing caused by variation in solar output at the sun’s surface that may cause changes in Cosmic Ray flux or other solar multiplier effects.
2. Changes in solar forcing caused by changes in the earth’s milankovitch cycles (Last Glacial Maxima, LGM) and volcanic activity that do not affect cosmic ray flux.
3. Changes in Anthropogenic Green House Gas (AGHG) concentrations.
The IPCC and others assume that climate sensitivity derived from #2 (Last Glacial Maxima, or Milankovitch cycles and volcanic activity) also applies to #1 and #3. This paper attempts to show that this is unlikely to be the case when the best available data is compared.
For #1 we found the climate sensitivity to be between 1.0°C and 1.8°C per Watt per Square meter of forcing. For #2 we found climate sensitivity to be approximately between 0.4°C and 1.2°C per W/M2 and for #3 we found climate sensitivity to be between 0.1°C and 0.36°C per W/M2.
INTRODUCTION
Climate sensitivity is the temperature increase at equilibrium for each Watt per square meter of forcing or “X” in the following equation. X°C/WM-2 .
Generally as the planet warms it activates various feedbacks. A negative feedback will decrease the earth’s system response time at the top of the atmosphere and a positive feedback will increase this response time. For example, a decrease in sea ice will slow the return of energy to space and can, therefore, be considered a positive feedback to warming.
Not all feedback’s, however, are a response to warming. For example, if the cosmic ray effect is real then it can be considered a positive feedback to increased solar activity that is not related to warming. Similarly different types of forcing can have different response times at the top of the atmosphere. I intend to show in this paper that changes in long wave GHG forcing have a considerably shorter response time than changes in short wave solar forcing and, therefore, can be expected to have a lower climate sensitivity.
I, therefore, intend to show that the IPCC’s climate sensitivity based on #2 above should not be applied to AGHGs.
I have used the IPCC’s climate sensitivity derived from #2 above to calculate the current equilibrium temperature due to AGHG’s already in the system and compared this with the NOAA actual temperature since 1880 in Fig. 1. The calculations done to produce the graph below are set out in Appendix “1”.
Basically the IPCC’s agreed CO2 concentrations were used to calculate expected equilibrium temperature which was adjusted using the IPCC’s 3rd and 4th assessment reports figures to include all AGHG’s (i.e. NO2, CH4, Halogens etc.). All calculations used to produce this graph (fig. 1) are generally agreed and accepted and used by the IPCC.
The inconsistency of the IPCC central prediction and upper limit with the actual data (blue line) is immediately apparent. It is possible that the lower IPCC limit might be compatible but even this becomes untenable when climate sensitivity to changes in Total Solar Irradiance (TSI) which include any solar multiplier effects, #1, is taken into account. This sensitivity, #1, will be estimated in section “A” below. Section “B” will show how the IPCC derived their climate sensitivity for #2 above.
The IPCC’s position is that industrial aerosols have artificially cooled the planet masking the warming effects of the AGHGs and that equilibrium temperature is approximately 1.5 times transient or current temperature. Section “C” will show that even these are not enough to avoid the conclusion that climate sensitivity due to changes in AGHGs, #3, is considerably smaller than both #1 and #2.
Fig. 1 AGHG Forced equilibrium temperature using the IPCC’s sensitivity based on #2 (LGM and volcanic) and compared to actual temperature as measured by the NOAA since 1880. The upper IPCC limit assumes a climate sensitivity of “X” = 1.2, the IPCC central prediction assumes “X” = 0.8, and the lower IPCC limit assumes “X” = 0.4.
#1. SECTION A We used two methods to match TSI (Total Solar Irradiance) changes as Watts/Square meter at the earth’s surface with the best temperature data available. These TSI changes will affect the cosmic ray flux and possibly have other solar multiplier effects as they are caused by changes in solar activity at the sun’s surface.
If these changes in TSI lead to greater temperature changes per unit forcing than solar changes that do not result in changes in the cosmic ray flux, such as Milankovitch cycles or volcanic activity, then this would lend some credence to theories suggesting that cosmic rays have a significant effect on the earth’s surface temperature.
The two methods we will use are a) compare solar irradiance changes over the last millennium with temperature records, and b) compare temperature and forcing for the 11 year sun cycle.
a) The TSI variations are taken from Swingedouw et al (2011) who used the Bard et al (2000) reconstruction and are the same as those used by Crowley (2000). The scaling used is from Lean et al (1995). Lean et al (2002) and Foukal et al (2004) suggest that long term irradiance changes could be considerably less which would imply a higher temperature sensitivity to a given forcing.
Fig. 2, W/M2 at the earth’s surface due to changes in Solar activity for the last millennium.
Fig. 3, Solar activity for the last 1100 years.
I have used the temperature reconstructions of Mann 2008 EIV, Moberg 2005, Loehle 2008 and Ljungqvist 2010 to represent temperature change over the last millennium. They are, I believe, the best available series at the time of writing. These temperature reconstructions are reproduced in Appendix “2”. An approximation of the range of temperature over this period is then compared with the range in solar forcing at the earth’s surface.
With considerable uncertainties, this comparison will give us an approximation of the climate’s sensitivity to changes in solar forcing at the earth’s surface that include any cosmic ray effect and/or other solar multiplier effects .
Fig. 4, Maximum and minimum temperatures for 4 different temperature reconstructions over the last 1500 years. The warmest three decades and the coolest three decades from each reconstruction are shown.
From fig 2 and fig 3 the range in solar forcing at the earth’s surface over the last 1000 years excluding the 20th century is approximately 0.6 w/m2.
From fig 4 the range in temperature in each of the four reconstructions can be seen. It is then possible to calculate “X” where X is the change in the earth’s surface temperature in degrees Celsius that results from a one w/m2 change in forcing.
From Fig 4 the range in temperature for Mann 2008 EIV is approximately 0.75°C, for Moberg 2005 is approximately 0.9°C, for Loehle 2008 is approximately 1.1°C and for Ljungqvist 2010 is approximately 0.9°C.
Climate sensitivity is described by the equation X°Celcius / wm-2. .
The value of “X” will change, with time from equilibrium, and with any other changes in the earth’s feedback systems etc. For the purposes of this paper, however, “X” will be considered to be linear for a given forcing. This paper is considering the possibility that “X” will change considerably depending on the nature of the forcing that drives any change.
The value of “X” is then derived for each of the four different temperature reconstructions.
For Mann 2008 “X” equals 1.25 (0.75/0.6)
For Moberg 2005 “X” equals 1.5 (0.9/0.6)
For Loehle 2008 “X” equals 1.8 (1.1/0.6)
For Ljungqvist 2010 “X” equals 1.5 (0.9/0.6)
These values of “X” should approximate the equilibrium response since the data is taken over a millennium or more. There are considerable uncertainties in these estimates of climate sensitivity that derive from the max/min method used and the error margins of the various temperature reconstructions used.
It is worth noting that if the max/min method used overstates the temperature response then it is also likely that max/min method also overstates the solar forcing at the earth’s surface causing some of the possible error to be cancelled.
It is beyond the scope of this paper to estimate these uncertainties other than to say that the climate sensitivity, as calculated from current knowledge by this method, probably lies in the range 1.25°C/wm-2 and 1.8°C/wm-2.
b) The 11 year solar cycle will also include changes in cosmic ray flux as it too results from changes in solar output at the sun’s surface.
Camp and Tung (2008) use the 11 year sun cycle to derive transient sensitivity of between 0.69 and 0.97°C/wm-2. They also estimate equilibrium temperature as being 1.5 times higher than this which is consistent with the IPCC’s position in their 4AR.
This gives an “X” value for climate sensitivity calculated by this method of between 1.04°C/wm-2 and 1.46°C/wm-2
Combining a) and b) we get the likelihood that climate sensitivity for TSI changes that include changes in cosmic ray flux and/or any other solar multiplier effect will probably lie between 1.0°C/wm-2 and 1.8°C/wm-2.
#2. SECTION B The second type of forcing is one that causes changes in solar energy reaching the earth without effecting cosmic ray flux. These include the Milankovitch cycles and volcanic activity that occur at the earth’s surface and, therefore, are not due to changes in TSI at the sun’s surface.
Annan and Hargreaves (2006) looks at climate sensitivity derived from observation of volcanic activity and the Last Glacial Maxima (LGM).
They studied the literature and concluded that volcanic activity indicates that climate sensitivity would be between 1.5°C and 6°C for a forcing of 3.7w/m2 at equilibrium with the upper limit constrained to 4.5°C after the 20th century temperature record and evidence from the Maunder minimum are considered.
Volcanic activity, therefore, gives a climate sensitivity of between 0.4(1.5/3.7)°C/wm-2 and 1.2(4.5/3.7)°C/wm-2 to 95% confidence.
A & H (2006), after studying the literature, concluded that LGM measurements support a climate sensitivity between 1.3°C and 4.5°C for a 3.7w/m2 forcing to 95% confidence. The upper limit was constrained for the reasons outlined above.
This gives a value for “X” between 0.4 and 1.2 derived from evidence taken from both volcanic activity and the LGM. This agrees closely with the IPCC’s position outlined in all of their assessment reports.
Fig. 5, IPCCs Forcing’s bar graph from their 2007 4AR. Note the large aerosol cooling effect they expect for 2005. Minimum -0.4w/m2, Likely -1.2w/m2, Maximum -2.4w/m2. Note also the large AGHG Forcing of approximately 2.7 w/m2 which at their central sensitivity of “X” = 0.8 should give an equilibrium temperature increase in 2005 of 2.16°C. This is not consistent with actual temperature rise as seen in Fig. 1.
That Milankovich Cycles are overwhelmingly the main drivers of the ice ages, and more particularly the LGM used by A & H (2006) to estimate their climate sensitivity, is shown convincingly by Roe (2006) “In Defence of Milankovich”.
#3. SECTION C Since 1880 an extremely active sun has added directly, approximately 0.5w/m2 at the earth’s surface (Fig. 2). According to our best historical temperature series as seen in section A and after an adjustment to give transient temperature, this active sun should have increased the earth’s temperature by a minimum of approximately 0.33°C to a maximum of 0.6°C since 1880.
According to the NOAA in Fig. 1 the earth’s temperature has risen by about 0.7°C since 1880.
This leaves between 0.1 and 0.37°C plus any industrial aerosol cooling effect to be explained by increasing AGHGs.
This can be summarised by the following equation;
Equation 1; “Y” plus (0.1 to 0.37) = “Z” Where “Y” is the net aerosol cooling in 2010 and “Z” is the total transient warming due to AGHGs in 2010.
At this point we introduce another check on aerosols to get a second simultaneous equation. According to Stern (2006) industrial aerosol production has fallen by over 30% since 1990, Fig. 6. Mishchenko confirms this with satellite measurements showing a drop in sun blocking aerosols since 1990, Fig. 7. Basically, If an increase in industrial aerosols gives a significant cooling as postulated by the IPCC then a drop in aerosols, as has happened since 1990, should cause a significant warming. Here is a supporting quote from the IPCC’s 4AR. “Global sulphur emissions (and thus sulphate aerosol forcing) appear to have decreased after 1980 (Stern 2005)…”
This drop in industrial aerosols can be explained by cleaner combustion techniques forced on people by acid rain and other undesirable environmental effects.
There are other contributors to the earth’s temperature other than Industrial aerosols, AGHGs, and solar, but they are negligible in the context of this paper.
To form a second simultaneous equation we need an estimate of AGHG forcing and an estimate of temperature change since 1990.
Fig. 6 Estimated global SO2 production. Stern 2006
Fig. 7.
The temperature series, Fig. 8, below gives a temperature rise between 1990 and 2010 of approximately 0.2°C. It is uncertain whether natural forcing’s would have increased or decreased this figure so we have approximated this figure to a rise of between 0.1°C and 0.3°C which is an estimate of the anthropogenic temperature change since 1990. The effect of the Mt. Pinatubo eruption in 1991 has also been removed.
Fig. 8 Earth’s temperature 1990 to 2010 according four main temperature series.
AGHGs added 0.82 w/m2 from 1990 to 2010, based on their increase in concentration, which is 28% of the total forcing, attributed to AGHGs in 2010 by the IPCC.
We can now create a second simultaneous equation;
Equation 2; 0.3 x “Y” Plus 0.28 X “Z” = 0.1 to 0.3
Solving for the simultaneous equations 1 and 2 gives total aerosol cooling of between 0.12°C and 0.34°C in 2010 (“Y”). This implies total AGHG forced transient warming in 2010 (“Z”) of between 0.22°C and 0.69°C.
If we assume equilibrium temperature is approximately 1.5 times transient temperature and use the IPCC’s total forcing of 2.9 w/m2 we arrive at an AGHG climate sensitivity of;
“X” = 0.11°C/wm-2 to “X” = 0.36°C/wm-2.
CONCLUSION
To my mind the IPCC’s upper limit and central prediction are not consistent with the NOAA actual temperatures in Fig. 1. If our best temperature series over the last 1000 years are to be believed then the IPCC lower limit in Fig. 1 can also not be reconciled with the actual measured temperatures as has been demonstrated in section A, B and C above.
The IPCC would put 4 possible arguments to explain the discrepancies apparent in Fig. 1.
1. That equilibrium temperature is considerably more than 1.5 times transient temperature which would overturn nearly all the literature on the subject and be inconsistent with all the IPCC’s model assumptions.
2. That industrial aerosols have a massive cooling affect which would be inconsistent with evidence since 1990 (see section C above). They would also need to explain the fact that industrial aerosols generally remain local and are overwhelmingly produced in the northern hemisphere. The northern hemisphere has experienced more warming over the last century than the southern hemisphere.
3. That AGHG sensitivity is not linear. It is initially lower and increases to their published sensitivity at doubling. It is therefore unlikely but possible that the IPCC’s lower limit of “X” = 0.4 could be consistent with the upper limit for AGHGs of “X” = 0.36. This would imply a much larger cosmic ray or other solar multiplier effect (minimum “X” = 1.0, see section A above) than is generally accepted.
4. That temperature measurements over the last millennium are so uncertain that no conclusions can be drawn from them. These are the best series (see appendix 2) that we have. The existence of the medieval warm period and the little ice age have been confirmed by many studies around the world and are not seriously challenged anymore. It can be safely stated that the IPCC’s estimated climate sensitivity range can be falsified by the best evidence that we have at the time of writing.
The IPCC’s position is that climate sensitivity measurements deduced from the LGM and volcanic activity that do not include any solar multiplier effect and are based on short wave solar radiation can be assumed to apply to Long Wave Radiation from AGHGs and changes in TSI at the sun’s surface that include possible solar multiplier effects.
This paper proposes that the IPCC’s position is not consistent with our best millennial temperature records nor is it consistent with Green House Gas Forcing and temperature rise in the 20th century (Fig. 1) without unrealistically large aerosol cooling. The IPCC’s position is particularly inconsistent when it is noted that aerosol levels have fallen over the last 20 years at a time when temperature rise has abated.
All the available data is neatly reconciled and consistent if we are prepared to accept that the earth’s climate sensitivity is different for long wave greenhouse gas forcing than it is for short wave solar forcing. It is, in fact, unlikely that these two would have the same sensitivity and there are good physical reasons why they wouldn’t.
PHYSICAL EVIDENCE
1. The existence of a cosmic ray effect on temperature has been debated for some time now and would explain the different sensitivities described in section “A” and section “B”. This is discussed in Shaviv 2005, “On Climate Response to Change in Cosmic Ray Flux and Radiative Budget.” Certainly the existence of some form of solar multiplier is supported by the evidence of the last millennium (section “A”) when it is compared with the IPCC’s sensitivity (section “B”). The IPCC’s climate sensitivity is derived from LGM and volcanic measurements that don’t include any solar multiplier effects as they are caused by changes at the earth’s surface as opposed to changes at the sun’s surface.
2. The climate response time is the time it takes for the atmosphere to respond to a change in forcing and is dependent on sensitivity and the amount of ocean mixing. Hansen, Sato and Kharecha, “Earth’s Energy Imbalance and Implications”, say “On a planet with no ocean or only a mixed layer ocean, the climate response time is proportional to climate sensitivity. ………..Hansen et al (1985) show analytically, with ocean mixing approximated as a diffusive process, that the response time increases as the square of climate sensitivity.”
If it can be shown that a change in the Long Wave Radiation from AGHGs has a shorter response time than a change in Short Wave Solar Radiation, then this would imply a lower climate sensitivity for changes in AGHGs than you would expect from changes in solar forcing.
It is well known and accepted physics that Long wave radiation from GHGs only penetrates the oceans to a depth of a fraction of a millimetre. Water is almost totally opaque to these wavelengths. Short wave solar radiation, on the other hand, penetrates water to a depth of 10 meters or more and is, therefore, readily involved in ocean heating.
There is clearly a significant difference in response times between Long wave radiation from AGHGs and the Short wave solar radiation used by the IPCC to calculate their sensitivity. Long wave radiation is returned almost immediately to the atmosphere while Short wave solar radiation is largely absorbed by the ocean and takes much longer to find its way back to the atmosphere on average.
It is entirely logical that shorter response times would equate to lower temperature sensitivities at equilibrium. There would quite obviously be less energy in the pipeline as the oceans are not warmed significantly by AGHG’s.
The IPCC and others argue that the warming of the top fraction of a millimetre by AGHGs prevents energy from escaping from the deeper ocean and, therefore, effectively has the same response time as solar radiation. This position is shown to be not correct by the simple experiment outlined in Appendix 3.
3. As you would expect the IPCC’s models and predictions are already starting to fail as a result of them using the wrong wavelength to estimate AGHG forced climate sensitivity. James Hansen’s catastrophic predictions to the USA congress in 1988 are compared with actual temperature in Fig. 9. They clearly don’t correlate.
Fig. 9 James Hansen’s 1988 predictions to the USA congress compared with actual temperature.
Here is a quote from the IPCC’s 2001 TAR, “..anthropogenic warming is likely to lie in the range of 0.1°C to 0.2°C per decade over the next few decades”, and another from the IPCC’s 2007 4AR “For the next 2 decades, a warming of about 0.2°C per decade is projected”. The earth’s temperature has remained level or fallen since both of these predictions were made.
APPENDIX 1
Fig. 1 AGHG Forced equilibrium temperature using the IPCC’s sensitivity based on #2 (LGM and volcanic) and compared to actual temperature as measured by the NOAA since 1880. The upper IPCC limit assumes a climate sensitivity of “X” = 1.2, the IPCC central prediction assumes “X” = 0.8, and the lower IPCC limit assumes “X” = 0.4.
The method used to plot this graph;
1. A preindustrial CO2 concentration of 280 ppm was assumed. CO2 concentrations since 1880 were taken from the IPCC pre 1960 and from Mauna Loa after 1960.
2. CO2 Forcing was calculated using the widely accepted formula ;
rF = 5.35 x ln(C/C0) wm-2
Where “C” is the current CO2 concentration and “Co” is the initial CO2 concentration. This formula is the basis for the IPCC’s position that a doubling of CO2 concentration will produce a Forcing of 3.71 wm-2. i.e. rF = 5.35 x ln (2) = 3.71 wm-2.
3. Based on the IPCC’s TAR and 4AR reports, the CO2 forcing was then multiplied by 1.66 to give the total forcing of all the AGHGs (NO2, CH4, Halogens etc.) See Fig. 5.
4. The IPCC’s equilibrium temperatures were then calculated using the IPCC’s sensitivity factors, 0.4 (lower), 0.8 (central), and 1.2 (upper). i.e. The IPCC’s central predicted equilibrium temperature for a doubling of CO2 is, therefore, 0.8 x 3.71 wm-2 or approximately 3.0°C.
5. All graphs were then zeroed at 1880, the time when relatively accurate thermometer temperature measurements commenced.
APPENDIX 2
The four main millennial temperature series summarised in Fig. 4.
Fig.10 Temperature series for the last 1000 years. Ljungqvist 2010 (Black Line), Loehle 2008 (Blue Line)
Fig 11. Moberg 2005 1000 year temperature record including more recent instrumental records.
Fig. 12 Mann 2008 EIV 1000 year temperature series.
APPENDIX 3
The simple experiment, attributed to Tallbloke, that proves that GHG increases do not significantly warm the oceans.
Konrad: Empirical test of ocean cooling and back radiation theory
Posted: August 25, 2011 by Tallbloke in atmosphere, climate, Energy, Ocean dynamics 68
Some background –
Willis Eschenbach had a guest posting over at WUWT in which he claimed that LWIR could heat Earth’s oceans. Myself and several others on the thread contended that this LWIR was likely to be stopped by the evaporative skin layer and would not slow the exit of heat from the oceans. Numerous requests for empirical evidence to support Willis’s claim only resulted in one inapplicable study used by the “Hockey Team” to support such claims. After several hundred comments without empirical evidence being offered, I gave up reading and designed and conducted an empirical experiment that shows that any effect of backscattered LWIR on the cooling rate of water would be negligible.
What follows is an edited version of the experiment design and results as posted on the WUWT thread. I would encourage others to conduct similar experiments to check my results. The equipment required is not overly expensive and the results can be observed in minutes. The results appear to show the measurable difference between reflecting LWIR back to warm water when it is free to evaporatively cool and when it can only cool through conduction and radiation.
What is required –
– Two identical probe type digital thermometers with 0.1 degree resolution
– Two identical insulated water containers. I used rectangular 200ml Tupperware style containers, insulated on their base and sides with foil and Styrofoam. I cut away the clip on rim from each lid to create a frame to clip down cling film for Test B of the experiment.
– One IR reflector. I used an A4 sheet of 10mm Styrofoam with aluminum foil attached with spray adhesive.
– One IR window. I built an A4 size “picture frame” of 10mm square balsa wood strips and stretched cling film over it.
– One 1 litre measuring jug
– Two small identical computer fans. I used Suron 50mm centrifugal blowers powered by a 6v gel cell battery
– Extra cling film
– Optional extras – kitchen timer, an A4 ”dark cool sky” panel of matt black aluminum with peltier cooling, glamorous lab assistant of choice.
What to do –
– Position probe thermometers in identical positions in both water containers. I placed the tips 10mm below the water line by drilling force fit holes in the sides of the containers.
– Position IR reflector and IR window 50mm above either water container. You may need to build two Styrofoam side walls, but air must be free to move over the surface of the water. (The use of the IR window is to ensure that air flow is similar over each water container.)
– Position the computer fans to blow across the water surface of each container, but do not turn on.
– Fill jug with warm water, stir, then fill each water container from the bucket. I used water around 40C as the ceiling was around 18C not a 3k sky.
– When and equal amount of water is in each container, turn on the computer fans.
– Observe the temperature change over time for each tank. Less than half an hour is required for such a small amount of water. You should observe that both tanks cool at the same rate (TEST A).
– Now the important bit – Repeat the experiment, but this time lay a small sheet of cling wrap on the surface of the water in each water tank. This allows cooling through radiation and conduction but prevents evaporation. You do not need the computer fans on in this test. You should be able to observe that while both containers cool slower than before, water under the IR reflector cools slowest (TEST B).
Interpretation –
In TEST A the water cools more quickly, however the two water containers temperatures remain very close to each other over time. This indicates that backscattered LWIR has a very limited effect on the rate of cooling for water when it is free to evaporatively cool.
In TEST B both water containers cool more slowly than Test A, but a divergence in temperature between the two water containers is readily detectable. The container under the foil sky cools more slowly than that under the cling wrap sky. This indicates that backscattered LWIR from a warm material can slow the rate at which that material cools, if radiation and conduction are the only methods for cooling.
Test A represents the evaporative cooling conditions in the real oceans. Test B represents how the climate scientists have modeled the oceans with regard to backscattered LWIR. From what I have observed, backscattered LWIR can slow the rate at which substances cool. However in the case of liquid water that is free to cool evaporatively this effect is dramatically reduced. It would appear that including the oceans in the percentage of Earth’s surface that could be affected by backscattered LWIR may be a serious error. Earth’s oceans cover 71% of the planet’s surface. If backscattered LWIR cannot measurably affect liquid water, then CO2 cannot cause dangerous or catastrophic global warming.
I have conducted further tests using a “cold sky” panel cooled with ice water over the top of the cling film IR window. While the temperature divergence in the evaporation restricted test B does not appear faster, it does appear to diverge for longer.
I would encourage others to conduct similar empirical experiments and share their observations. I would be interested in comments in further experimental design, or empirical evidence related to the LWIR question.
Typical TEST A
| Time | Cling Wrap Screen | Foil screen |
| 0 | 37.1 | 37.1 |
| 5 | 33.2 | 33.2 |
| 10 | 29.4 | 29.4 |
| 15 | 27 | 26.9 |
| 20 | 25.5 | 25.5 |
| 25 | 24.5 | 24.5 |
Typical TEST B
| Time | Cling Wrap Screen | Foil screen |
| 0 | 38.2 | 38.2 |
| 5 | 36.3 | 36.6 |
| 10 | 34.8 | 35.3 |
| 15 | 33.5 | 34.2 |
| 20 | 32.6 | 33.4 |
| 25 | 31.5 | 32.6 |
richardscourtney says (April 6, 2013 at 2:54 pm): “…the energy transfer used by my microwave oven is conducted by electromagnetism. Similarly, the back-radiation to the Earth’s surface is conducted by electromagnetism.
In both cases there is an external source of energy: unless, of course, you want to claim the Sun is not a source of energy?”
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As it so often happens, existence of back radiation is confused with the alleged warming effect of back radiation. Back radiation exists, but it apparently neither warms the source nor slows down the cooling rate of the source.
It is not the Sun that makes the back radiation in question. It is the radiation of the body (source), like Erarth surface or whatever that produces radiation and then this radiation hits a reflector or CO2 or whatever. The result is back radiation. You have been around this debate for years and still won’t get it? It is hard to believe.
I suggest you just stand in front of a mirror or something covered with a nice IR reflecting material and enjoy the heat radiated back to you. Then be so kind and report this scientific experimental experience here, please.
george e. smith says:
April 6, 2013 at 4:56 pm
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George
Thanks your comments. I do not have a copy of G.C. Ewing (ed.), “Oceanography from Space.” so my response is thereby limited.
As I stated in my first comment, the data comes from the Scienceofdoom website article on back radiation heating the oceans. The LWIR absorption data I used is from Figure 7 of their article headed “Ocean Transmission of DLR by wavelength” The zoomed plot can be viewed at: http://scienceofdoom.files.wordpress.com/2010/10/dlr-absorption-ocean-matlab.png . Have a look at that plot.
I presumed (I know a dangerous thing) that their reference to DLR is to LWR in the wavelengths that we are particularly interested, ie., those of back radiation not simply from CO2 but from a composition of all GHGs coming down from on high.
The scienceofdoom article (http://scienceofdoom.com/2010/10/06/does-back-radiation-heat-the-ocean-part-one/) contains in Figure 4 details of a paper by Wozniak titled “Light Absorption in Sea Water”, Wozniak (2007). A zoomed in scan of the relevant plot can be viewed at http://scienceofdoom.files.wordpress.com/2010/10/from-light-absorption-in-sea-water-wozniak-2007-499px.png
This plot, of course, is not the absorption characteristics of long wave EM but rather that of (approximately) vissible light. It is interesting in that in broad terms it appears to give a similar profile to that which you set out for light in the wavelength range of above 300nm (nanometres), ie., maximum transmission is at 300nm, a minima at 400nm, rising again at 500 to 600nm, and then falling from 900 through to 1300nm. I should emphasise that the wavelengths in this plot are expressed in nanometres not micrometers. 300 nanometres is of course 0.3 micrometres, not 3 micrometres.
I find this plot interesting merely because the shape characteristic appears similar to what you are describing from the Ewing book. This leads me to wonder whether you may have (in some way) converted the scaling used in the Ewing plot to which you refer. Have another look at the Ewing plot, and have a look at the Wozniak (2007) plot and compare the same.
Have you by any chance erroneously converted nanometres into micrometres? I do not mean any disrespect but since I cannot check the Ewing book, I just wonder whether there may be something in the point I raise (ie., that 300nm is 0.3 micrometres not 3 micrmetres). Please just clarify.
PS. As you know scienceofdoom is a pro AGW site, so it would surprise me if they made a mistake in the absorption characteristics of long wave radiation which error goes against AGW. It is in their interests to demonstarte that long wave radiation from DLR (I refer to as DWLWIR) penetrates the ocean to greater depth. I seem to recall (but I have not rechecked) that Wikipedia (also known for its warmist stance) contains similar information on the absorption of DLR in water. I seem to recall that it also contains the plot which scienceofdoom set out in Figure 7.
George
Further to my last post, once I had submitted my comment, I consider that I have somewhat misdescribed the Figure 4 plot when describing it as approximately vissible light.
When I gave it that description late at night (it is about 4am) I had in mind the peak between 300 to say around 700nm, thinking that that s broadly vissible wavelengths. Of course, this plot extents beyond vissible light.
Greg House says: April 6, 2013 at 6:11 pm
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This experiment is best done in a hall of mirrors, for maximum effect.
I have been in a curved room with mirrored walls, and i am still here to tell the tale. I was not roasted alive from all that back radiation, even though there were about 30 other people in the room all radiating heat. Those mirrors were sure re-radiating an awful lot of heat in a never ending spiral (to misquote that song The Windmills of Your Mind) of energy.
When people raise space blankets, I often comment to similar effect. A space blanket keeps the user warm because it hinders convection, not because of back radiation.
If a space blanket were to use back radiation as its effective means of keeping the patient warm, it could be constructed like a toilet roll. The roll could have a diametre of say 60cm and be say 2 metres in height with the patient standing inside the roll enjoying the radiation and re-radadiation off the never ending mirrored curved surface. Heck, it would not matter if the diametre were not 60cm but was say 1 metre or 5 metres or even 10 metres. There would still be the same measured back radiation for the patient to enjoy and to keep the patient warm.. But of course, that nasty thing called convention rears it’s ugly head, so in the real world, it just don’t work like that.
Nick Stokes,
Bob Irvine has posted material from an experiment I built in 2011. At the time I wrote “If backscattered LWIR cannot measurably affect liquid water, then CO2 cannot cause dangerous or catastrophic global warming.”
I was wrong.
Liquid water that is free to evaporatively cool does respond very differently to incident LWIR than other materials. However this on its own does not disprove the radiative green house hypothesis. The radiative green house hypothesis would fail for a desert planet as well. Experiments 2 to 5 posted earlier on the tread here –
http://wattsupwiththat.com/2013/04/05/a-comparison-of-the-earths-climate-sensitivity-to-changes-in-the-nature-of-the-initial-forcing/#comment-1267231
– show why the radiative green house hypothesis fails for a moving atmosphere.
Experiment 2 demonstrates the ability of CO2 to radiate energy it has acquired by conduction. Most of the net energy being radiated to space by radiative gases was acquired by surface conduction and the release of latent heat.
Experiment 3 demonstrates that convective circulation in fluid in a gravity field can be driven by removing energy from the top of the fluid. Radiative gases do this in our atmosphere. Adiabatic cooling of ascending air masses does not represent a loss of energy from the air mass and therefore does not create a loss of buoyancy.
Experiment 4 demonstrates two important things. First, the relative height of energy input and output for a gas column in a gravity field determines whether convective circulation develops. Secondly, in box 2 where strong convective circulation does not develop, the average gas temperature is higher. Heated gases rise to the top of box 2 and do not descend. Cooling in box 2 is limited to the speed of gas conduction. The bigger you build the experiment, the better it works. Heating and cooling a gas column in a gravity field a separate locations at the base results in a higher average temperature than heating at the base and cooling at the top.
Experiment 5 demonstrates the folly of treating gas as a static body when calculating surface to gas conductive flux. The two tubes cool at different rates. In tube 1 with the cling film at the top, convective circulation develops, bringing the hottest air against the cooling surface and maximising conductive flux. In tube 2 with the cling film at the base, gravity keeps the coldest gas against the cooling surface, minimising conductive flux. The same effect works in our atmosphere. Gravity moves the coldest gases against the surface during the day, maximising conductive flux into the atmosphere. Gravity moves the coldest gases against the surface at night, minimising conductive flux out of the atmosphere. This experiment also demonstrates why conductive flux between the surface and atmosphere should not be calculated from surface Tav. Land surface Tav may be lower under a non radiative atmosphere, but this does not translate to a cooler atmosphere.
In 2011 I was wrong to claim experiment 1 disproved CAGW. Experiments 2 to 5 however prove that the radiative green house hypothesis fail for an atmosphere in a gravity field in which the gases move. I should also note that the ERL hypothesis also fails for an atmosphere with moving gases.
Radiative gases are critical for convective circulation in the troposphere. Radiative gases act to cool the troposphere at all concentrations above 0.0ppm. An increase in convective circulation speed or tropospheric cooling from the addition of trace amounts of CO2 to the atmosphere would be impossible to detect against natural variability.
In reply to dp
dp says:
April 5, 2013 at 11:31 pm
….Bottom line is energy in the sea has to pass through the atmosphere to get back to space where it came from and any lid you put on it, ice, clouds, CO2, is going to inhibit that.
William:
I would assume you are stating that increased atmospheric CO2 will cause warming as that has been repeated over and over again in the media and by some scientists.
The scientists who have been pushing the AGW paradigm have been holding back information concerning the paleoclimatic record and information concerning the 20th century warming Vs predictions.
There are periods of millions of years when atmospheric CO2 was high and the planet was cold and periods of millions of years when atmospheric CO2 was low and the planet was low. In the geological past CO2 does not correlate with planetary temperature.
Curiously the 20th century warming has not global. The tropics and the Southern Hemisphere experienced almost no warming. The 20th century warming occurred in the high Arctic and high latitudes in the Northern Hemisphere. The CO2 warming theory predicted that the largest amount of warming on the planet due to the increased CO2 would be in the tropical troposphere at around 10 km above the surface of the planet. (The CO2 mechanism will warm the region that receives the most amount of radiation and as water vapor amplifies the CO2 warming the tropics should also warm the most. The tropical troposphere warming at 10 km was then predicted to warm the tropics which would in turn warm the remaining planet. There is no observed tropical troposphere warming at 10 km.
There is a physical reason for that observation and for the observation planetary temperature does not in correlate with atmospheric CO2 in the paleoclimatic record. Certainly a significant reason is the IPCC (GCM) models incorrectly model clouds.
Lindzen and Choi’s research indicates that planetary cloud cover increases or decreases (negative feedback) in the tropics to resist any forcing change. If the planet resists rather than amplifies the warming due to CO2, the warming due to a doubling of atmospheric CO2 will be less than 1C. Negative feedback is likely a significant reason for the lack of correlation of atmospheric CO2 and planetary temperature in the past, however, as the 20th century is not in the regions predicted by CO2 theory (i.e. It is not global.) it is likely there are multiple errors or something is fundamental incorrect reality vs simplified model.
The tropics receives the largest amount of solar radiation, water vapor was predicted to amplify the warming. The lower troposphere is saturated with CO2. Additional CO2 atmospheric therefore was not predicted to warm the lower troposphere directly.
The 20th century warming was primarily in the Northern Hemisphere and in the Arctic. As the region of warming does not match the CO2 mechanism, scientists should have looked for another explanation. Unfortunately any warming has accepted as CO2 warming which is ridiculous, irrational. If we compare a criminal investigation to a scientific investigation, the prosecutor must explain the observations, must prove the suspect was at the scene of the crime, that the suspect has capable of the crime, and so on. In this case atmospheric CO2 is not capable of causing the warming pattern observed.
Curiously there is in the paleoclimatic record cycles of warming and cooling that exactly match the pattern of warming observed in the 20th century, Dansgaard-Oeschger cycles. There is coincidental with the D-O cycle a cyclic change to solar magnetic cycle. It appears the past warming and cooling cycle was caused by the solar magnetic cycle.
What is missing is a full explanation as to how the sun changed in the past and how the solar magnetic cycle like changes caused the planetary warming and cooling.
squid2112 says:
April 6, 2013 at 9:25 am
Greg House says:
April 6, 2013 at 6:11 pm
————————————————————————————
Squid & Greg,
AGW is a failed hypothesis, however getting the radiative physics wrong does not do sceptics any favours. So you can get a better understanding of LWIR I have two simple experiments for you that demonstrate LWIR slowing the cooling rate of materials.
Greg,
On a cold clear night with no wind, go outside and hold a 100mm square of aluminium foil 20mm away from your cheek with the shiny side toward you. As your skin cools in the cold air, one cheek will feel warmer. Outgoing LWIR from your skin is being reflected back, very slightly slowing the cooling rate of that skin.
Squid2112,
AGW believers and sceptics alike are not claiming IR from a cold body can make another body hotter than the cold body. Rather that IR from one body can slow the cooling rate of another. On a cold (10C) clear night with no wind, go outside and hold a coke can filled with 15C water 20mm away from your cheek. As your skin cools in the cold air, one cheek will feel warmer. LWIR emitted from the 15C coke can is slowing the cooling rate of your skin, even though your skin is at a higher temperature.
The radiative green house hypothesis fails not because of problems in radiative physics (although they got the liquid water thing wrong), but because the original calculations involved modelling a static atmosphere or in the worst cases modelling a combined surface and atmosphere. The gases in our atmosphere move and radiative gases, most importantly water vapour, play a critical role in tropospheric convective circulation.
Konrad says (April 6, 2013 at 8:30 pm): “AGW is a failed hypothesis, however getting the radiative physics wrong does not do sceptics any favours. So you can get a better understanding of LWIR I have two simple experiments for you that demonstrate LWIR slowing the cooling rate of materials. …On a cold clear night with no wind, go outside and hold a 100mm square of aluminium foil 20mm away from your cheek with the shiny side toward you. As your skin cools in the cold air, one cheek will feel warmer. Outgoing LWIR from your skin is being reflected back, very slightly slowing the cooling rate of that skin. …AGW believers and sceptics alike are not claiming IR from a cold body can make another body hotter than the cold body. Rather that IR from one body can slow the cooling rate of another.
==============================================================
OMG (shock)!
OK, I should not have allowed me to express my feelings in this scientific discussion. Let me start with your second point: “AGW believers and sceptics alike are not claiming IR from a cold body can make another body hotter than the cold body. Rather that IR from one body can slow the cooling rate of another.”. Yes, they are implicitly. Because if a warmer body has a stable temperature (thanks to an internal heat source, for example), then according to your concept back radiation from a colder body would heat that warmer body up, then the warmer body would heat the colder body even more thus getting from it even more back radiation and so on, and this would lead to more energy produced by the system than it is possible. Here your concept drops dead on the theoretical level.
As for you “experiment”, if you hold something “20mm away from your cheek”, you suppress convection. Provided the air temperature is lower than your skin temperature, it would reduce convective cooling of your skin and your cheek would indeed feel warmer.
Now, it can theoretically be both, but your experiment does not prove it. The same way you could prove that saying “abracadabra” turns your TV on. It goes like that: say “abracadabra” and push the power button on your remote. If your TV turns on, you have proven it, congratulations.
In this thread, a number of well meaning people claim that modern climatological models make predictions. These claims are false. These models make projections. They do not make predictions.
Richard Verney thankfully points out, from time to time, that GHGs radiate omnidirectionally. It is usually said, to make it simple, that half of the photons go up and the other half down.
I hope, that nobody will hold it against me if i now posit, that half of the radiation goes to the right and half goes to the left, or half in front and half backwards – nearly none of it touching the earth. Generosity makes me finally say, one sixth of the photons goes in each of 6 directions – which reduces, to simplify, downwelling radiation to 16.5% of the whole radiation.
Greg House says:
April 6, 2013 at 9:30 pm
———————————————————————
Greg,
try holding the foil in a vertical orientation, and then compare results by substituting a square of matt black card 😉
I will try one last time. The only thing that climate scientists have gotten wrong with radiative physics is the effect of LWIR on the surface of liquid water in contact with a gaseous atmosphere. However the ability of water molecules to undergo phase change to gas at this interface makes this a special case. This mistake does not on its own invalidate the radiative green house hypothesis. The hypothesis is invalid because the linear flux equations they have used do not work for an atmosphere with moving gases.
– Almost all solids and liquids above 0 kelvin emit IR photons
– IR photons from a cooler object impacting the surface of a hotter object can slow the cooling rate of the hotter object.
– IR photons from the surface of a cooling object reflected back to its surface will slow its rate of cooling.
– IR photons incident on the surface of an object with an internal heat source will raise its equilibrium temperature
– IR photons from one object cannot raise the temperature of the receiving object higher than the emitting object, unless there is a further source of energy heating the receiving object.
Greg, radiative physics is fine. I have demonstrated in the empirical experiment that Bob Irvine posted that the cooling rate of materials can be slowed by reflecting IR photons emitted by the cooling material back to its surface.
I have demonstrated the failings of the AGW hypothesis through repeatable empirical experiment. I am sure that I am not the only WUWT reader distressed at you continuing disbelief of radiative physics. You have made repeated claims in this area. It is high time you conducted your own empirical experiments to support your claims. Type is cheap.
There are physical reasons why the 20th century warming occurred. The physical reasons/mechanisms must explain why the 20th century warming has not global. The CO2 warming mechanism predicted/projected (William: A person above had a problem with the term predicted and suggested projected. I am not sure I understand the difference. Please elaborate.) that the majority of the warming should have occurred in the tropics. It did not. The majority of the 20th century and early 21st warming occurred in the Arctic and above the Greenland Ice sheet.
Attached immediate below is a link to a graph that shows how temperature has change on the Greenland Ice for the last 12 thousand years. It clearly shows cycles of warming and cooling which are called Dansgaard-Oeschger cycles. The D-O cycles correlate with solar magnetic cycle changes. Something in the past caused the cyclic warming and cooling on the Greenland Ice sheet. The something, the physical cause is not changes in atmospheric CO2. The past D-O cycles appears to match the 20th century warming. I attempted to present this information and information from a series of published papers that outline how solar magnetic cycle changes and geomagnetic field changes modulate planetary temperature at RealClimate and was told the information was ‘off message’ and I would be blocked.
A disingenuous comment or theory is a theory made or comment made by a person how knows that there is other information that disproves the comment or theory. Our legal system is based on the premise that the prosecution is required to explain and not hide data that exonerates as well as convinces the accused. Science is based on the premise that scientists are interesting in determining the physical cause of what is observed, as opposed to pushing a specific theory for personal motives.
http://climate4you.com/images/GISP2%20TemperatureSince10700%20BP%20with%20CO2%20from%20EPICA%20DomeC.gif
This is the site where the above graph is located.
http://climate4you.com/GlobalTemperatures.htm#Recent%20global%20satellite%20temperature
http://www.agu.org/pubs/crossref/2009/2009JA014342.shtml
If the Sun is so quiet, why is the Earth ringing? A comparison of two solar minimum intervals.
Observations from the recent Whole Heliosphere Interval (WHI) solar minimum campaign are compared to last cycle’s Whole Sun Month (WSM) to demonstrate that sunspot numbers, while providing a good measure of solar activity, do not provide sufficient information to gauge solar and heliospheric magnetic complexity and its effect at the Earth. The present solar minimum is exceptionally quiet, with sunspot numbers at their lowest in 75 years and solar wind magnetic field strength lower than ever observed. Despite, or perhaps because of, a global weakness in the heliospheric magnetic field, large near-equatorial coronal holes lingered even as the sunspots disappeared. Consequently, for the months surrounding the WHI campaign, strong, long, and recurring high-speed streams in the solar wind intercepted the Earth in contrast to the weaker and more sporadic streams that occurred around the time of last cycle’s WSM campaign.
The following paper shows planetary temperature tracks the parameter Ak (Ak measures how much the geomagnetic field changes in a 3 hour period. Ap measures how much the geomagnetic field changes in 24 hours. Large, lumpy changes to the solar wind cause the greatest changes to Ak.)
http://sait.oat.ts.astro.it/MSAIt760405/PDF/2005MmSAI..76..969G.pdf
Once again about global warming and solar activity K. Georgieva, C. Bianchi, and B. Kirov
We show that the index commonly used for quantifying long-term changes in solar activity, the sunspot number, accounts for only one part of solar activity and using this index leads to the underestimation of the role of solar activity in the global warming in the recent decades. A more suitable index is the geomagnetic activity which reflects all solar activity, and it is highly correlated to global temperature variations in the whole period for which we have data.
In Figure 6 the long-term variations in global temperature are compared to the long-term variations in geomagnetic activity as expressed by the ak-index (Nevanlinna and Kataja 2003). The correlation between the two quantities is 0.85 with p<0.01 for the whole period studied.It could therefore be concluded that both the decreasing correlation between sunspot number and geomagnetic activity, and the deviation of the global temperature long-term trend from solar activity as expressed by sunspot index are due to the increased number of high-speed streams of solar wind on the declining phase and in the minimum of sunspot cycle in the last decades.
William: The solar wind changes create a space charge differential in the ionosphere which in turn affects the global electric circuit.
The review paper linked to immediately below discusses two mechanisms by which the solar magnetic cycle changes modulate planetary temperature:
1) Modulation of galactic cosmic rays GCR by the solar heliosphere. GCR are mostly high speed protons which are believed to accelerated by magnetic fields created in super nova) by which solar magnetic cycle changes are believed to modulate planetary temperature. The solar heliosphere is the name for a region of space about the sun that changes as the solar magnetic cycle progress. Pieces of the solar magnetic field are carried off into space by the solar wind. The pieces of magnetic field in the solar heliosphere deflect the GCR. GCR strike the planet’s atmosphere creating ions. Ions affect the formation of clouds, albedo of clouds, and the lifetime of clouds. Modulation of GCR is one of the mechanisms by which solar magnetic cycle changes affect planetary climate.
2) Modulation of the Global electric circuit by solar wind bursts. As noted below, solar wind bursts create a space charge differential in the ionosphere which removes cloud forming ions. Solar cycle 22 and 23 had an increase in solar wind bursts at the end of the solar cycle. These solar wind bursts removed cloud forming ions, so even though GCR has high there was a reduction in planetary clouds which caused the planet to warm.
http://www.utdallas.edu/physics/pdf/Atmos_060302.pdf
See section 5a) Modulation of the global electrical circuit in this review paper, by solar wind bursts and the process electroscavenging. Solar wind bursts create a space charge differential in the ionosphere which removes cloud forming ions. As the electroscavenging mechanism removes ions even when GCR is high, electroscavenging can make it appear that GCR does not modulate planetary cloud if the electroscavenging mechanism is not taken into account.
The above review paper summarizes the data that does show correlation between low level clouds and GCR.
2. CORRELATIONS OF CLOUD PROPERTIES WITH DECADAL GCR AND SUNSPOT VARIATIONS
Among the many reported decadal timescale correlations of meteorological parameters with solar activity, one of the least ambiguous as an effect of space particle fluxes on clouds is that shown in Figure 2.1. This is a correlation of precipitation and precipitation efficiency with GCR flux in the Southern Ocean that is greatest at the highest geomagnetic latitudes, where the amplitude of the GCR flux variations and the associated vertical current density (Jz) variations are greatest [Kniveton and Todd, 2001].
The location of the geomagnetic pole is marked by an X. The precipitation data were from the Climate Prediction Center Merged Analysis of Precipitation (CMAP) product. The amplitudes of the precipitation and precipitation efficiency variations were 7-9% at 65-75 Degree geomagnetic latitudes and at those latitudes the GCR flux and Jz vary by 15-20% over the solar cycle. The statistical significance of the correlation with GCR flux is better than 95% over a large oceanic region as shown in Fig. 2.1. There is a tendency for reversed correlation at lower latitudes.
William Astley:
You request an explanation of the difference between a “prediction” and a “projection.” Good question! An explanation follows.
There is a kind of model that makes a predictive inference. An example of this kind of inference is:
Given that is cloudy,
the probability of rain in the next 24 hours is 30 percent.
Given that it is not cloudy,
the probability of rain in the next 24 hours is 10 percent.
A predictive inference extrapolates from one unspecified state of nature to another. For example, it extrapolates from an unspecified state in the set {cloudy, not cloudy} to an unspecified state in the set {rain in the next 24 hours, no rain in the next 24 hours}. Conventionally, the states in the first type of set are called the “conditions” while the states in the second type of set set are called the “outcomes.” A condition and an outcome are properties of a kind of event in a statistical population. In my example, one kind of event has the condition “cloudy” and the outcome “rain in the next 24 hours.”
A “prediction” is like a predictive inference but the condition is specified. For example, with the condition “cloudy” specified, the prediction of the predictive inference described above is:
The probability of rain in the next 24 hours is 30 percent.
Today’s climate models do not make predictions. They cannot make them, for a prediction corresponds to an event in the statistical population that underlies the model but for today’s climate models there is no such population. However, these models do make projections. A “projection” is a mathematical function that maps the time to the computed and spatially averaged air temperature near Earth’s surface.
People, including professional climatologists, are inclined to conflate predictions with projections through claims that today’s climate models make predictions. However, to do so is to imply that a statistical population underlies each of today’s climate models when there are no such populations.
That these populations are nonexistent has implications for global warming climatology that are perfectly ghastly. One of them is that the scientific method is not being followed in the execution of these studies though professional climatologists claim the scientific method is being followed. That global warming climatology is defective in this way is a reality that should not be obscured by misapplied terminology.
richardscourtney @April 6, 2013 at 2:54 pm
Richard, how could you state that a cool body heats up a warmer one, if you accept an external source of energy in the system, source which supply the whole energy to the heating of the warmer body?
Maybe you was not aware of it, but the whole energy which heated your beacon came from the magnetron; that is, it came from the power grid, NOT from your cold oven frame!
That’s not a thermodynamic heat exchange of the two bodies involved in the oven-beacon system.
squid2112 was right, making the appropriate assessment that I did about the external work/energy inputs to the system.
When you write about the Sun energy you are just making my point. The Sun energy is a third party in the two bodies system, but squid2112 wrote about ONE warmer body which can’t be heated by ONE cooler body.
Massimo
Greg House says:
April 6, 2013 at 6:11 pm
Back radiation exists, but it apparently neither warms the source nor slows down the cooling rate of the source.
Please, som explanation how it is possible that the same surface with the same moisture content and starting at the same temperature cools much faster under open sky vs. under clouds at night?
feliksch says:
April 6, 2013 at 11:22 pm
I hope, that nobody will hold it against me if i now posit, that half of the radiation goes to the right and half goes to the left, or half in front and half backwards – nearly none of it touching the earth.
Nothing against you, but the earth is a little larger than you expect: near halve what is going left and right still is touching the surface, be it over a longer distance, depending of the height of the emitting molecule…
Ferdinand Engelbeen (April 6, 2013 at 1:03 pm) wrote:
“[…] a solar cycle also shifts the jet streams poleward at high solar activity and reverse together with the accompanying cloud and rain patterns (cause: more UV – more ozone – higher temperature in the equatorial lower stratosphere – more temperature difference between equator and poles at that height). The impact on regional climate in general is huge […]”
Earth’s climate and the heliosphere share a common decadal structure & cadence.
Earth’s climate and the heliosphere share a common multidecadal structure & cadence.
Earth’s climate and the heliosphere also share a common centennial structure & cadence. (new illustrations forthcoming)
The dark agents of ignorance &/or deception mess with the choice of markers, aggregation criteria, & inferential assumptions to make sure the public remains ignorant &/or deceived about this.
The sensible thing to do is straight up reject and shut down darkly ignorant &/or deceptive intimidation — i.e. tell them go away creep and don’t ever speak to me again. It’s that simple.
@richard Verney
Regarding your no. 10: overturning
I have faced the same question when trying to work out the heat transfer from hot gasses upward to a flat pot. It looks simple to start with.
I was assisted by Prof Snow, Univ of London, who was able to show, once given a correct problem description, that the buoyancy effect of the hot rising fluid was about 30 times the overturning power. This is of course based on the Reynolds Number, the velocities and temperatures involved.
I suggest that you have described the same problem expressed in terms of rising heat (overall) and the overturning forces. The pot is replaced by the sky and the heat source applies the heat via IR, largely.
It seems to me that overturning waves pushed by the wind cause far more and deeper stirring than the day/night effect which might in the end be ignored – not sure yet. But picking up your point about rising and day/night overturning the departure point would be to quantify them both first then consider how waves overpower the net result, and under what conditions.
Ferdinand Engelbeen says:
April 7, 2013 at 3:04 am
//////////////////////////////////////////////
One would expect a difference, if for no other reason than convection.
Putting a lid on a sauspan reduced the rate at which the contents therein cool, not because the lid back radiates heat, but because the lid limits convection thereby effectively traping heat. Clouds play a similar function.
Perhaps you should explain why the height of cloud cover has a bearing on temperature. The height has no impact on the availability of back radiation, or even on the shielding from the ‘cold’ of outter space, but it does have an effect on convection.
Finallty, are you suggesting that back radiation only exists when cloudy? So if cloudiness only exists on average in various regional bands say 30% of the time or 40% of the time, or what have you, then for those bands the amount of DWLWIR should be reduced accordingly to reflect the duration of their average cloudiness.
Massimo PORZIO says:
April 7, 2013 at 2:59 am
squid2112 wrote about ONE warmer body which can’t be heated by ONE cooler body.
As said by others, that is true, but the cooling rate of the warmer body can be slowed down by the presence of a cooler body.
Imagine a warm body in space, without any other body in the neighbourhood. The rate of cooling is the amount of energy emitted in all directions, which is strongly temperature dependent and the heat content of the body mass.
Then bring a cold (anywhere over 0 K) body in the neighbourhood. The radiation of the warm body in first instance doesn’t change, but the radiated energy of the cold body will reach the warm body where no external heat input existed before. If the warm body absorbs any amount of these cold body radiation (thus not 100% reflective), there is less decrease in heat content than without the cold body.
The amount of energy received by the warm body from the cold one anyway is less than reverse, because of the difference in temperature and thus radiative energy transfer per surface area. That means that the cooling rate of the cool body will be more slowed down (even may heat up, if the warm body is much larger and/or hotter) than the effect of the cold body on the slow down of the warm one.
In no case it is possible that a cold body will warm up a warmer one without the use of some kind of IR magnifying glass…
Konrad says:
April 6, 2013 at 11:32 pm
///////////////////////////////////
Konrad
Have you ever measured to see whether any low incident LWIR is reflected off water (or off ice)?
By low incident, I mean LWIR inter-acting at an angle of say 15deg or less to the surface?
It may be that because water is such a good absorber of LWIR, no LWIR is reflected. However, it may be that some small amount of low incident LWIR is simply reflected from the surface.
It appears that you have the experimental equipment. I would be interested in learning the result.
beng says:
April 6, 2013 at 6:15 am
Points:
1. Please get the historical solar forcing right — it’s essentially constant….
>>>>>>>>>>>>>>>>>>>>>>>>>>>>
That like everything else is a point of contention.
This is what the Principal Scientist says, you know the guy with the DATA…
There are plenty of other NASA articles and other papers of a similar nature.
richard verney says:
April 7, 2013 at 4:29 am
One would expect a difference, if for no other reason than convection.
Perhaps you should explain why the height of cloud cover has a bearing on temperature. The height has no impact on the availability of back radiation, or even on the shielding from the ‘cold’ of outer space, but it does have an effect on convection.
Height has direct impact on cloud temperatures, thus also on back radiation.
There were a lot of measurements in The Netherlands about clouds, including upwelling and downwelling radiation of visible and IR spectra. The simple conclusion: the downwelling IR spectra show the base temperature of the cloud and its height above ground. With open sky the IR “temperature” drops below the instrument range of -50°C, thus indicating a huge difference in backradiation. See Fig. 3 in:
http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-85-10-1565
Quite an interesting story…
Finally, are you suggesting that back radiation only exists when cloudy?
No, but water vapour and liquid water are far more effective in backradiation in a lot of wavebands than GHGs. But clouds act in both ways: reflecting more incoming sunlight, thus less insolation at the surface during the day and more backradiation at night. That makes that the diurnal variation is lowest during cloudy days and largest with open skies…
Gail that report was from 2003 and YOU KNOW new information questions, nay reverses, that position on solar trend. You are a respected commenter here. Please question the dates of the articles you link to. New information is gathered all the time. But those who ignore new information, or better understanding of old information, run the risk of becoming irrevelant (just like climate models).
This is what the Principal Scientist says, you know the guy with the DATA…
NASA’s page link has moved to:
http://www.giss.nasa.gov/research/news/20030320/
Ferdinand Engelbeen says:
April 7, 2013 at 7:36 am
////////////////////////////////////
i don’t disagree with all you say, but nothing is that simple. Where I live in Spain, we have these past months had many cloudy days where the temperature struggles around the 18 to 20deg C mark and at night (also cloudy) the temperature is around 4 to 8 degC. So a diurnal range of say about 13degC.
in summer, we will usually experience cloudless days and cloudness nights. The day time temp will typically be about 32degC and the nighttime temp 28degC, so a diurnal range of about 4 degC.
So there can be less range in cloudless conditions; many factors influence the temperatures that one experiences, clouds being just one. I suspect that their blocking of incoming solar far outweighs the effect of any notional backradiation.