Guest Post by Willis Eschenbach
The CERES dataset is satellite data that is based on radiation measurements made from low earth orbit. The CERES data has two parts. The first part is observational data, measurements of downwelling and upwelling solar radiation and of upwelling longwave radiation. It is usually referred as the CERES “top-of-atmosphere” data. The official name is “CERES EBAF-TOA”, and it is available here.
However, the second part of the CERES is not top-of-atmosphere observations from the satellite. Instead, it is calculated surface data based on the CERES TOA observations along with other satellite observations. It’s called the “CERES EBAF-Surface” dataset, and is available from the same location.
As a result, I’ve always been concerned about the accuracy of the CERES surface data. After all, it’s just calculations, it’s not actual observations. So I got to thinking that I could “ground-truth” the CERES surface observations by using the TAO buoy data. It’s not a comprehensive test by any means, but the TAO buoys cover a region of great interest to me, the tropical Pacific. The TAO buoy data is available here.
I started out by seeing how well the CERES surface longwave radiation data agreed with the TAO sea surface temperature (SST) data. Now, the CERES dataset doesn’t have SST data, but we can convert the CERES surface radiation data into temperature by using the Stefan-Boltzmann relationship. First I looked at a string of TAO buoys that run along the Equator. I used the location of each TAO buoy, and compared it with the CERES surface calculated result for that location. Figure 1 shows that comparison for the eight TAO buoys along the Equator which have SST data.
Figure 1. Sea surface temperatures (SST) from the TAO buoys (red) and from the CERES surface data calculations (blue).
I was pleasantly surprised by this result. The greatest bias is ± two tenths of a degree, and the correlation is very high, 0.97 to 0.99.
Having looked at an east-west line of buoys, I then looked at a north-south line of buoys. These are all at 165°E, in the warmest area in the Pacific.
Figure 2. Sea surface temperatures (SST) from the TAO buoys (red) and from the CERES surface data calculations (blue).
Again the correlations are good, although there is one of the seven down at a correlation of 0.92. And the bias is slightly larger, -0.3 to -0.4°C. In this region all of the CERES data is slightly below the TAO buoy data.
Overall, however, if the bias errors are only on the order of a few tenths of a degree and the correlation is on the order of 0.97 or better, I’m more than happy to say that the sea surface temperature is extremely well represented by the CERES surface calculations.
However, that’s the easiest of the variables. Next I looked at something much harder to estimate—the available solar radiation at the surface after atmospheric reflection, absorption, and scattering. Figure 3 shows the available solar measurements from buoys along the Equator.
Figure 3. Available surface downwelling solar after atmospheric reflection, absorption, and scattering from the TAO buoys (red) and from the CERES surface data calculations (blue).
This one surprised me quite a bit. I wouldn’t have guessed that the satellite calculations would come this close. Not only do they get the annual cycles right, but they also get the occasional departures from the annual cycles. Yes, the correlation of some of them is lower, but they still do a good job. And the bias in all cases is less than 2%, a respectable showing.
I then looked at the same group of north-south buoys I’d used above. Here are those results.
Figure 4. Available surface downwelling solar after atmospheric reflection, absorption, and scattering from the TAO buoys (red) and from the CERES surface data calculations (blue).
Again, a very good showing, with correlations from 0.87 to 0.97, and bias of less than 2%.
There is one more overlapping dataset between CERES and TAO, that of downwelling longwave radiation (DLR). Unfortunately, there are only five TAO buoys with DLR data, and one record is very short … but we use what we have. Here is that group of buoys.
Figure 5. Downwelling longwave radiation (DLR) from the TAO buoys (red) and from the CERES surface data calculations (blue).
Of all of the results, I was most surprised by this one. I would say that this one would be the hardest to calculate from the satellite data. But despite that, if we set aside the very short (5-month) dataset in the first panel of Figure 5, the other four have good correlations (0.82 to 0.97), and the three longer datasets (panels 2, 3, and 4) have a bias of well under 1%.
Conclusions? Well, as I said, this is far from a comprehensive test … but I am greatly encouraged nonetheless. The CERES surface dataset, despite being calculated rather than observed, is a very good match to the TAO buoy data in all available respects. Makes me feel much better about using it.
My regards to you all,
w.
PS-If you disagree with someone please have the courtesy to quote the exact words you disagree with. This lets all of us understand the exact nature of what you think is incorrect.
“convert the CERES surface radiation data into temperature by using the Stefan-Boltzmann relationship.”
What was the emissivity used; 1?
DocMartyn,
This came up on Willis’ SURFRAD article a few months back, and IIRC using an emissivity of unity worked rather well.
Emissivity includes a “time” component. If you don’t know the lag between when the energy came in and when it was subsequently emitted, and if you don’t have several days of all these measurements timed to the trillionith of a second, then what is the emissivity?
Heat up an iron bar in a room at room temperature. The iron bar will absorb the energy for quite some time before its starts to emit that energy back. The emissivity is therefore Zero.
After you stop adding energy to that iron bar, it continues to emit energy until it reaches room temperature. Emissivity is therefore infinite and is actually an undefined quantity.
Emissivity has been used as a redirection for far too long. We are talking about objects that absorb energy and re-emit virtually all of that energy within picoseconds. At most, it is a few minutes to an hour. Emissivity can be assumed to be 1.0 unless you can measure all those “time elements” to a pico-second level.
Measure the emissivity of soil throughout a 24 hour day and then come back and tell us assuming 1.0 is not correct. If one actually did so, one would find that the soil is emitting back virtually 99.999992% (0.008 joules/second divided by 1000 joules/second) of the energy it is receiving in any one second. That difference is enough to allow the soil to slowly warm up throughout the day by 15C or so and then slowly release that energy throughout the night so that it is about the same temperature the next morning. I call that close enough to 1.0.
Bill Illis, Willis E.
True, very true. These calc’s “assume” that temperatures are static, are in equilibrium.
But they are not: You’ve made a good assumption for the static (stays in place) soil mass exposed to solar radiation. The steel bat heats up to a static temperature within 15 minutes (1 x 1 x 48 inch, heated at one end by an oxy-acetelyne torch will get that hot. then stay at the same temperature as long s the heat continues to be applied.
BUT.
The heat into the bar (the end being heated) is not “all” going out as radiation. (Which, for an isolated planet in space, or an isolated/insulated/insolated iceberg sitting in space radiated by the sun on only one side, you can “sort of” make that assumption. But the steel bar I heat up with the torch is losing heat by conduction down the bar, by conduction to the clamp and the vise it is held up by, by convection of the air around the bar, and (where it like the iceberg sitting the Arctic Ocean, by evaporation and air flow by the wind across the top and by convection into the water below.
ALL of those heat transfer mechanism go on simultaneously. So, you CANNOT p”calibrate nor even compare the radiated heat out of an iceberg/ice cap to the radiation received. Too much other heat transfer mechanisms are going on.
Reflected thermal SW and IR radiation occurs instantaneously. Conducted heat is lost more slowly. Convection (by definition) is lost to the other moving liquid or gas. That gas must be removed from the surface to be replaced by fresh fluid.
Radiation thermal loss is “instantaneous” but the energy lost is only that which can get transported (usually by convection and conduction) from another area to the radiating area. (Power supply gets hot, power supply heats a radiator, radiator fin starts to get hot and begins radiating. But that fin is not yet as hot as the original power supply was. And it will never get as hot as the original power supply. )
RA Cooke said
“ALL of those heat transfer mechanism go on simultaneously. So, you CANNOT p”calibrate nor even compare the radiated heat out of an iceberg/ice cap to the radiation received. Too much other heat transfer mechanisms are going on. ”
Absolutely right and that goes to the heart of a point I put to Willis and others elsewhere, namely, that if energy is involved in conduction/convection it cannot also radiate at the same time.
That is why I propsed a separate adiabatic energy exchange between surface and atmosphere which is maintained as long as insolation continues whilst new radiative energy coming in flows straight out again through a discrete diabatic energy exchange between surface/atmosphere and space.
The global thermostat can then seen to be the adiabatic energy exchange which varies precisely and oppositely with variations in the diabatic energy exchange.
Convection acts as the regulator between radiation and conduction and duly reapportions energy between those two processes as necessary to maintain thermal equilibrium at any given level of incoming radiation.
.
Stephen Wilde says, February 23, 2015 at 12:32 am:
“(…) if energy is involved in conduction/convection it cannot also radiate at the same time.”
The ‘radiationers’ are seemingly completely blind to this fact. And they have been blinded by invariably looking at cases where such other heat transfer mechanisms for various reasons are not operating, that is, where the heat transfer is purely radiative. So they interpret all the radiation laws as if they were universal. But they are only universal in … purely radiative situations.
Stephen 12:32am, Kristian 4:39am: “..if energy is involved in conduction/convection it cannot also radiate at the same time….The ‘radiationers’ are seemingly completely blind to this fact.”
Radiationers? LOL, please now explain who they would be. Note that CERES only measures radiative energy data. As Stephen notes CERES is blind to energy transport in surface conduction/convection (thermals) or evapo-transpiration at the same time – yet Willis work shows the surface temperature data is reasonably calculable from CERES radiative only data. No knowledge of the energy in thermals or evapo-transpiration is necessary to get the surface temperature from CERES EBAF. Maybe Kristian’s blind ‘radiationers’ are on to something. Is Willis thus a radiationer?
Trick says, February 23, 2015 at 6:03 am:
“Radiationers? LOL, please now explain who they would be.”
People like you, Trick. Thanks for presenting yourself 🙂
“Note that CERES only measures radiative energy data.”
CERES only measures radiances from the ToA to space, Trick. It doesn’t ‘measure’ any UWLWIR flux at the surface, if that’s what you think.
Kristian 8:00am: CERES measures incident radiation at its orbit so if you read top post again understand EBAF calculated reasonable surface temperature from that radiation data as Willis shows. Call it what you will.
Trick says, February 23, 2015 at 8:56 am:
“CERES measures incident radiation at its orbit so if you read top post again understand EBAF calculated reasonable surface temperature from that radiation data as Willis shows. Call it what you will.”
You don’t get it, do you? CERES couldn’t possibly calculate surface temps from its own IR flux readings from space alone. It could only possibly ever do so by determining peak wavelength of the atmospheric window radiation.
Did you notice the part about CERES needing lots of additional input from other sources to its heat transfer model in order to be able to calculate anything at all at the surface?
You can find out about it upthread. Or you can check this out:
http://ceres.larc.nasa.gov/documents/cmip5-data/Tech-Note_CERES-EBAF-Surface_L3B_Ed2-8.pdf
Kristian 9:35am – I know that Kristian, that’s why they call it CERES EBAF-Surface. You should read your own link to learn about the EBAF “radiationer” (Kristian term) processing that Willis writes about in the top post – which does a reasonably “good showing” (Willis term) calculating surface temperature using remote sensing methods when Willis compared to TAO buoy in situ measured sea surface temperature (SST). There are whole books written on remote sensing, recommend Kristian brush up on one.
Trick says, February 23, 2015 at 10:56 am:
“You should read your own link to learn about the EBAF “radiationer” (Kristian term) processing that Willis writes about in the top post – which does a reasonably “good showing” (Willis term) calculating surface temperature using remote sensing methods when Willis compared to TAO buoy in situ measured sea surface temperature (SST).”
Yes, and this has exactly what to do with my original comment about the ‘radiationers’ that you replied to? In none of your responses here have you addressed at all what I actually pointed to. Only performing good ol’ misdirection.
This is a very nice piece of analysis. However, the surface temperature is estimated by observing the LWIR emission through the atmospheric transmission window. There is no connection between the atmospheric LWIR emission from the water and CO2 bands at the top of the atmosphere and the surface temperature. The atmospheric emission to space is rate limited by the water vapor concentration. The water band emission changes in altitude as the heat stored in the troposphere changes.
The troposphere is an open cycle heat engine, not an IR spectrometer. The temperatures in the troposphere are determined by the lapse rate, not the LWIR emission. The LWIR flux is fully coupled to the heat capacity of the troposphere. It cannot be treated independently. The radiative change in temperature is the time integrated change in LWIR flux divided by the heat capacity. Almost of the LWIR flux exchange between the troposphere and the surface takes place within the first 2 km layer of the troposphere and a third to a half of this is within the first 100 m of the surface. The LWIR emission to space is from the middle to upper troposphere. This is the cold reservoir of the atmospheric heat engine. Energy conservation only requires that the net long term emission to space from the cold reservoir and the transmission window balance the absorbed solar flux. Heat is stored and released by the climate thermal reservoirs, and by water evaporation and condensation.
Ocean surface temperatures are determined by the energy balance between the solar heating, the net LWIR emission and the wind driven evaporation. All of the cooling and LWIR absorption/emission occurs within an ocean surface layer less than 1 mm thick. The cooler surface water then sinks and cools the ocean below. Approximately half of the solar flux is absorbed within the first 1 m layer of the ocean and about 90% total is absorbed within the first 10 m layer.
In good round numbers, in the Pacific warm pool, under full tropical sun illumination at a surface temperature near 30 C, the average solar flux of 250 W m^-2 is balanced by 50 W m^2 net LWIR cooling and 200 W m^2 of wind driven evaporation at an average wind speed near 5 m s^-1. A change of 1 m s^-1 in wind speed changes the evaporative cooling by 40 W m^-1. The total increase in net LWIR from CO2 over the last 200 years is approximately 2 W m^-2. In the warm pool this corresponds to a change in wind speed of 5 cm s^-1. This change in CO2 flux is far too small to have any effect on surface temperatures.
The ocean evaporation depends on the difference in ocean and air humidity and the wind speed. This has been investigated in detail by Lisan Yu and coworkers at Woods Hole, http://oaflux.whoi.edu/heatflux.html.
How much heat is removed from the oceans by wind driven evaporation? This is real source of weather and climate change.
Ah, but you use “average” numbers there.
On the water surface near the equator, the ocean actually receives over 1000 watts/m^2 at noon, and 900+ watts/m^2 from 9:00 to 15:00 (pm) .. and near-zero at other times. So, your evaporation rate, and heat up rates for that square meter need to reflect not the average heat received, but the instantaneous heat gain and heat loss.
DOY = 53 LAT Deg = -4 -0.06981317 = LAT Rad Hour Tau Decl HRA SEA SEA Air DIR DIR DIR Cos(SZA) Ocean Watts Watts radian radian degree Mass atten. perp horiz radian albedo absorb refl 0.00 0.895 -0.1829 -3.1416 -1.3180 -75.5 0.000 0.000 0 0 -0.968 0.000 0 0 1.00 0.896 -0.1827 -2.8798 -1.2079 -69.2 0.000 0.000 0 0 -0.935 0.000 0 0 3.00 0.897 -0.1822 -2.3562 -0.7492 -42.9 0.000 0.000 0 0 -0.681 0.000 0 0 5.00 0.899 -0.1816 -1.8326 -0.2437 -14.0 0.000 0.000 0 0 -0.241 0.000 0 0 7.00 0.900 -0.1811 -1.3090 0.2698 15.5 3.706 0.344 479 128 0.267 0.201 102 26 9.00 0.902 -0.1806 -0.7854 0.7845 44.9 1.414 0.666 926 654 0.706 0.066 611 43 11.00 0.903 -0.1800 -0.2618 1.2888 73.8 1.041 0.741 1031 990 0.960 0.066 925 65 12.00 0.904 -0.1798 0.0000 1.4608 83.7 1.006 0.749 1041 1035 0.994 0.066 966 68 13.00 0.904 -0.1795 0.2618 1.2890 73.9 1.041 0.741 1031 990 0.961 0.066 925 65 15.00 0.906 -0.1790 0.7854 0.7846 45.0 1.414 0.666 926 654 0.707 0.066 611 43 17.00 0.907 -0.1784 1.3090 0.2697 15.5 3.706 0.344 479 128 0.266 0.201 102 26 19.00 0.909 -0.1779 1.8326 -0.2442 -14.0 0.000 0.000 0 0 -0.242 0.000 0 0 21.00 0.910 -0.1774 2.3562 -0.7505 -43.0 0.000 0.000 0 0 -0.682 0.000 0 0 23.00 0.912 -0.1769 2.8798 -1.2119 -69.4 0.000 0.000 0 0 -0.936 0.000 0 0 7088 6577 511 Note: Every other hour shown, all 24 used in totals. total total total watt-hr watt-hr watt-hrThis calculation displays direct radiation only, today (22 Feb) for lat -5 south.
Atmosphere attenuation = 0.75 per measurements (Bason, Accra, Ghana 2006. Clear days, no clouds, 5.5 degree Lat N.)
Regarding the emissivity of soil – the description above is of the soil slowly changing temperature with the sun besting down and thus the E value is high, nearly One. A counter argument is that there is conduction of heat into the ground.
Soil has an emissivity of about 0.93, is a poor conductor and the difference in heat gain is probably loss of moisture. Obviously soil is different in colour from place to place, but 0.93-0.95 is a pretty good start for making calculations. Not very many ordinary objects are 0.99. A fresh, untouched, sooty pot bottom is a possibility.
Dry soil heats up Far more rapidly than damp soil. And conducts less. Water and water vapour have a higher emissivity than soil (and most things).
“Approximately half of the solar flux is absorbed within the first 1 m layer of the ocean and about 90% total is absorbed within the first 10 m layer. ”
From the article http://wattsupwiththat.com/2013/10/28/solar-spectral-irradiance-uv-and-declining-solar-activity/ the graphic below indicates his estimate, which varies from yours, where the integrated solar spectral energy ocean penetration looks to equal 50% at about 0.1 meter, not 1 meter. Please correct me if that’s wrong.
http://wattsupwiththat.files.wordpress.com/2013/10/ocean-penetration-by-solar-spectrum1.png
Thanks, Willis – a very informative and useful analysis.
There was a lot of “ground truthing” of this data both before and during the era of the current satellites. We participated in an exercise at the NASA Marshall Spaceflight Center (MSFC) where our satellite would carry narrowband filters at the knee of the curve (3db point for you EE’s), of the absorption features in the visible spectrum. These were the same filters (bandwidth wise [5,7,10 nanometers]) as would have been carried on the Terra and Aqua satellites.
At MSFC they were going to have a spectral radiometer that would have the same filters, thus enabling the establishment of the bi direction extinction coefficients for the principle absorption features in the visible band. While our satellite was never able to do this due to a malfunction in the receiver. This has been done for well over a decade at MSFC and as Steve Mosher pointed out, at LARC as well. NASA JPL also has the AVRISS program which is a high altitude version of the space based sensors.
Thus, there is considerable validation of these measurements.
The problem is that they have not gone back and taken the historical data from the USAF from the 1950’s where this was first measured down to the individual wavelengths to then to a qualitative comparison at the individual absorption/emission line level (especially in the IR), so that we could get the proper calculations done.
Most on the AGW community use Plass’s measurements from the late 50’s and early sixties. (Gavin Schmidt specifically references his papers). However, Kaplan showed that Plass’s measurements were more than a factor of 2 off (exaggerating the effect of CO2) over the actual measurements done by the USAF at the time.
Part of the problem is that we have lost a lot of this old data (technoarchaeology again), and thus this allows FUD to be spread by the pro AGW community that may not be justified.
SOO … you have some nice correlations … but where is the “surface data graph” calculated from this wonderful correlation??
Maybe the woodfortrees guys could add the CERES calculated surface temperature to the mix on their site …. so as to allow comparisons with the other products, … um .. like GISS!! We might just find that NASA has conflicting data within its own offices!!
Eric Worrall February 22, 2015 at 12:49 am
Reply
evanmjones February 22, 2015 at 6:15 am
Thanks, Evan. Those “two satellite metrics” don’t include CERES. They are the UAH MSU satellite temperature data product and the RSS MSU satellite temperature data product.
Reply
See – owe to Rich February 22, 2015 at 2:47 am
And a good question it is. As I said in the head post, the datasets I’m using are the “EBAF” datasets. This stands for “energy balanced and filled”. This means that the datasets are internally consistent and consistent with the actual TOA satellite observations. There’s a flowchart here showing the path from the raw spectrally-resolved radiance data to the 1° gridded EBAF calculated surface output. There’s also an excellent surface data quality summary here.
Now, Eric’s question was
I’d say the answer is that the scientists involved did a good job with the energy balancing and filling. In addition, although the CERES data is not super accurate, it is very precise.
Well … that’s a bit hard to say. The problem with looking just at downwelling LW is that if the planet warms or cools, the atmosphere warms and cools, and so we’d expect the corresponding up/down changes in the downwelling LW radiation.
Lemme take a look … well, that’s interesting. There’s no increase in surface downwelling longwave over the 14 years of the CERES dataset. In fact, it’s gone down by 0.5 ± 0.15 W/m2 per decade, p-value 0.00, over the period March 2000 to February 2014.
However, that may or may not mean that CO2 is not absorbing more upwelling CO2. The measure for that is how much upwelling radiation is absorbed by the atmosphere … hang on …
OK, atmospheric absorption has increased by 0.7 ± 0.1 W/m2 per decade, p-value = 0.00. So there’s another oddity for you … atmospheric absorption of upwelling longwave has gone up, but downwelling surface radiation has gone down.
I would add that both of these represent “porpoising values” that have gone both up and down over the period, and that the data is very short. So I wouldn’t put too much weight on the very slight trends of about half a W/m2 change over ten years … other than to note that half a W/m2 change in ten years is pretty dang stable.
Nothing like settled science …
w.
Willis, thank you for your replies, especially those new trends you calculated. I was beginning to think you had gone away and left us, but looking at the time stamps and considering your time zone, I am presuming that sleep was a good reason for part of it.
Cheers,
Rich.
Willis, very interesting. However, you say:
“OK, atmospheric absorption has increased by 0.7 ± 0.1 W/m2 per decade, p-value = 0.00.”
Where exactly did you get this information from?
I thought it was the oceans that were supposed to hold back the energy, accounting for the (postulated) ToA radiative imbalance over the last decade and a half …
Good question, Kristian. The atmospheric absorption is from the CERES dataset. It’s calculated as the difference between two datasets, as the surface upwelling longwave minus the TOA upwelling longwave.
Best regards,
w.
Ah, I see. Cheers 🙂
Willis: What about the consumption of energy via net primary productivity – like plant growth?
In the paper,
Loeb, Norman G., et al. “Toward optimal closure of the Earth’s top-of-atmosphere radiation budget.” Journal of Climate 22.3 (2009): 748-766.
http://www.nsstc.uah.edu/~naeger/references/journals/Sundar_Journal_Papers/2008_JC_Loeb.pdf
Loeb states ”In an equilibrium climate state, the global net radiation at the TOA is zero.”
… yet I find no mention of energy stored by photosynthesis.
Brian February 23, 2015 at 7:29 am
Interesting question, Brian. While there is energy stored by plants, it’s basically a zero-sum game due to the energy released when the plants die and decay. Overall the two balance each other out.
w.
Readers might first want to familiarize themselves with
http://ceres.larc.nasa.gov/documents/STM/2006-10/0610260830Doelling.pdf
to catch a few definitions.
While browsing that document, I was able to lift these bullet points:
There are 4 main CERES product groups
–
ERBE-like
• Uses ERBE algorithms to derive fluxes
–
SRBAVG Non-GEO
• Uses the CERES ADMs to derive fluxes
–
SRBAVG GEO
• Adds geostationary fluxes to improve temporal sampling
Appropriate Usage:
The CERES SRBAVG GEO product is the most robust CERES TOA monthly mean flux product, and of climate quality.
• Most regions sampled twice a day with either Terra or Aqua
• Terra & Aqua sample the poles up to 14 times/day
• Even after combining Terra and Aqua, 8 hour gaps exist
• PM-AM differences can be ~ 30 W/m^2
• Regional instantaneous differences can be ~ 100 W/m^2
• 3-hourly GEO fluxes adequately samples the diurnal cycle between ±60° latitude
• ERBE temporal interpolation assumes constant meteorology (cloud properties) through out the day
• Over land a half-sine fit is used to model diurnal heating if night time observations exist (Sine fit does not capture peak daytime heating) Boldface added by me.
I was astonished to note that most regions are sampled twice a day, yet morning and afternoon differences can be 30W/m^2 and instantaneous differences can be 100W/m^2 … and gaps between passes of satellites are 8 hours! How many ” instantaneous differences” of 100W/m^2 get ignored? There is a graph of a half-sine wave model-fit, which states that it does not capture peak daytime heating, and the graphic depicts a mismatch on the lower half, too.
I’m a believer that the earth heats up at the equator, and vents heat to space at the poles (a gross approximation, I’m sure…) so I find the depictions that have equator-centered images, a little lacking. That other part of the bullet point – 3-hourly GEO fluxes “adequately samples” between ±60° latitude … what is missed between N60° to N90° and S60° to S90° latitude?
… saving the best for last, they assume “constant meteorology” throughout the day? As little as a 5% increase in clouds would be able to deflect all the “global warming” flux:
Apr 2014: “… a 5% increase of [Stratocumulus clouds’] coverage would be sufficient to offset the global warming induced by doubling CO2”, a conclusion that is also stated by the studies conducted by Randall et al. (1984), Slingo (1990), Bretherton et al. (2004) and Wood (2012).
Lin, Jia-Lin, Taotao Qian, and Toshiaki Shinoda. “Stratocumulus Clouds in Southeastern Pacific Simulated by Eight CMIP5–CFMIP Global Climate Models.” Journal of Climate 27.8 (2014): 3000-3022.
http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-13-00376.1
To anyone interested, read my long rant, models can’t do clouds at http://wattsupwiththat.com/2014/12/11/mixed-signals-from-the-noaa-enso-blog-about-climate-models/#comment-1811783
Willis replied: “While there is energy stored by plants, it’s basically a zero-sum game due to the energy released when the plants die and decay. Overall the two balance each other out.”
I understand the concept, but we’re not in a steady-state condition. Increased CO2 is causing a 9% to 200% increase in Net Primary Production (1) and I wonder what amount of energy is consumed.
CERES will end up counting every erg, joule, and BTU of “fossil fuel” burned, as waste heat. Maybe that is what is cancelled by Net Primary Production.
Wills, this really isn’t for you, but it seems a good time to post my notes on Net Primary Production as my footnote #1. Folks seem to like the links and brief summary…
2009: ”… both gross, and net, primary productivity has likely increased over recent decades, as have tree growth, recruitment, … and forest biomass. … potentially from rising atmospheric CO2 concentrations, is the most likely cause.”
Lewis, Simon L., et al. “Changing ecology of tropical forests: evidence and drivers.” Annual Review of Ecology, Evolution, and Systematics 40 (2009): 529-549.
http://www.planta.cn/forum/files_planta/changing_ecology_of_tropical_forests_evidence_and_drivers_133.pdf
2014 Dec NASA NCAR Press Release: ”… add more carbon dioxide to the atmosphere, forests worldwide are using it to grow faster, reducing the amount that stays airborne. This effect is called carbon dioxide fertilization.” Also known as the β effect.
https://www2.ucar.edu/atmosnews/news/13659/tropical-forests-have-large-appetite-carbon-dioxide
2015: ”Feedbacks from terrestrial ecosystems to atmospheric CO2 concentrations contribute the second-largest uncertainty to projections of future climate. These feedbacks, acting over huge regions and long periods of time, are extraordinarily difficult to observe and quantify directly. ”
”the carbon cycle is second only to physical climate sensitivity itself in contributing uncertainty”
”Our results, however, show significant tropical uptake and, combining tropical and extratropical fluxes, suggest that up to 60% of the present-day terrestrial sink is caused by increasing atmospheric CO2. ”
”Photosynthesis increases with increasing CO2 following a Michaelis−Menton curve, and this effect grows stronger at higher temperatures”
Schimel, David, Britton B. Stephens, and Joshua B. Fisher. “Effect of increasing CO2 on the terrestrial carbon cycle.” Proceedings of the National Academy of Sciences 112.2 (2015): 436-441.
http://reddcommunity.org/sites/default/files/field/publications/increased_CO2_Schimel.pdf
”Rising atmospheric [CO2] … fertilizes plants (Liebig, 1843; Arrhenius, 1896; Ainsworth & Long, 2005).”
Zaehle, Sönke, et al. “Evaluation of 11 terrestrial carbon–nitrogen cycle models against observations from two temperate Free‐Air CO2 Enrichment studies.” New Phytologist 202.3 (2014): 803-822.
http://c-h2oecology.env.duke.edu/pdf/np12697-14.pdf
2012: Plants grown under controlled conditions of 700 ppmv CO2 “increased both root length (35.6%) and root dry weight (39.1%) densities.”
► “Fine root length density in the top two depths increased by 64.5 and 57.2%.”
► “Fine root dry weight density in the top two depths increased by 80.3 and 82.8%.”
Prior, S. A., et al. “Sour orange fine root distribution after seventeen years of atmospheric CO2 enrichment.” Agricultural and forest meteorology 162 (2012): 85-90.
http://www.sciencedirect.com/science/article/pii/S016819231200144X
“…CO2-enriched trees to have consistently sequestered approximately 2.8 times more carbon than the control trees over a period of three full years.”
Idso, Sherwood B., and Bruce A. Kimball. “Downward regulation of photosynthesis and growth at high CO2 levels No evidence for either phenomenon in three-year study of sour orange trees.” Plant Physiology 96.3 (1991): 990-992.
http://www.plantphysiol.org/content/96/3/990.short
“… plant growth and yield have typically increased more than 30% with a doubling of CO2 concentration …may decrease evapotranspiration… if the climate warms, the average growth response to doubled CO2 could be consistently higher than the 30% mentioned above … in nutrient-poor soil, the growth response to elevated CO2 has been large … under [conditions of] water-stress, the CO2 growth stimulation is as large or large than under well-wateredconditions … plant growth and crop yields will probably be significantly higher in the future high-CO2 world.”
Kimball, B. A., et al. “Effects of increasing atmospheric CO2 on vegetation.” Vegetation 104.1 (1993): 65-75.
http://link.springer.com/article/10.1007/BF00048145#page-1
Carrot and Radish plant productivity “significantly increased by a 300 ppm increase in the CO2 content of the air at all temperatures encountered, but with progressively greater effects being registered at higher and higher temperatures. At 25°C, the productivity enhancement factor for radish was about 1.5, while for carrot it was approximately 2.0.” Plants were grown in a 700 ppmv CO2 environment.
Idso, S. B., and B. A. Kimball. “Growth response of carrot and radish to atmospheric CO2 enrichment.” Environmental and Experimental Botany 29.2 (1989): 135-139.
http://www.sciencedirect.com/science/article/pii/0098847289900452
Doubling of atmospheric CO2 concentration “increased agricultural weight yields by [33% – 36%. Doubling of CO2 likely will] “reduce transpiration by 34% … water-use efficiency may double.”
”Greater CO2 concentrations will probably boost agricultural production with less water consumption, which will be a boon to Earth’s ever-expanding population.”
“… the most comprehensive review of CO2 effects on ultimate harvestable yield has been presented by Kimball (1982) who examined more than 70 reports about effects of CO2 enrichment on the economic yields and growth of 24 crops and 14 other species, and extracted more than 430 observations.”
“Elevated CO2 concentrations have had an overwhelmingly positive effect on yield (Kimball, 1982). Of 437 separate enriched samples, only 39 yielded less than their respective controls. Of this group, 20 were flower crops, whose yields were measured by number of flowers rather than by weight.”
Kimball, B. A., and S. B. Idso. “Increasing atmospheric CO2: effects on crop yield, water use and climate.” Agricultural Water Management 7.1 (1983): 55-72.
http://www.uu.nl/faculty/science/EN/contact/depts/biology/research/chairs/Palaeoecology/projects/AzollaProject/intranet/literature/AzollaandCO2/Documents/Kimball1983.pdf
Trees grown in 700 ppmv CO2 concentrations ”had grown 2.8 times larger than the ambient-treated trees; and they have maintained that productivity differential…”
Idso, Sherwood B., and Bruce A. Kimball. “Tree growth in carbon dioxide enriched air and its implications for global carbon cycling and maximum levels of atmospheric CO22.” Global Biogeochemical Cycles 7.3 (1993): 537-555.
http://onlinelibrary.wiley.com/doi/10.1029/93GB01164/abstract
“… cassava will respond with increased biomass accumulation in response to raising atmospheric CO2 levels …”
Further experiments with nitrogen fertilizer showed the toxic effects of the form of nitrogen, but that doesn’t change the conclusions of enhanced growth from CO2.
”The challenge is to determine how to manage NH4 + fertilization so that the photosynthetic benefit observed in the initial phase may persist throughout the crop cycle.”
Cruz, Jailson L., et al. “Effect of elevated CO2 concentration and nitrate: ammonium ratios on gas exchange and growth of cassava (Manihot esculenta Crantz).” Plant and Soil 374.1-2 (2014): 33-43.
http://link.springer.com/article/10.1007/s11104-013-1869-8#page-1
“Elevated CO2 stimulated plant growth by 10.8% [to as much as] 41.7% for a C3 leguminous shrub, Caragana microphylla, and by 33.2% [to as much as] 52.3%for a C3 grass, Stipa grandis, across all temperature and watering treatments … C4 grass, Cleistogenes squarrosa, 20.0% [to as much as] 69.7% stimulation of growth occurred with elevated CO2 under drought conditions.”
Xu, Zhenzhu, et al. “Effects of elevated CO2, warming and precipitation change on plant growth, photosynthesis and peroxidation in dominant species from North China grassland.” Planta 239.2 (2014): 421-435.
http://link.springer.com/article/10.1007/s00425-013-1987-9#page-1
Enhanced growth of spring wheat (Triticum aestivum L.) under 550 ppmv CO2 were found to be “cultivar dependent” with an increase in productivity of 42% to as much as 53% for the cultivar called Yitpi, but less for the H45 variety.
Thilakarathne, Chamindathee, et al. “Intraspecific variation in leaf growth of wheat (Triticum aestivum L) under Australian Grain Free Air CO2 Enrichment (AGFACE): Is it regulated through carbon and/or nitrogen supply?” Functional Plant Biology (2014).
http://www.publish.csiro.au/view/journals/dsp_journals_pip_abstract_scholar1.cfm?nid=102&pip=FP14125
“…current carbon-cycle models underestimate the long-term responsiveness of global terrestrial productivity to CO2 fertilization. This underestimation of CO2 fertilization is caused by an inherent model structural deficiency…”
“Global carbon cycle models have not explicitly represented this … and underestimate photosynthetic responsiveness to atmospheric CO2.”
“This increase represents a 16% correction, which is large enough to explain the persistent overestimation of growth rates of historical atmospheric CO2 by Earth system models. Without this correction, the CFE for global GPP is underestimated by 0.05 PgC/y/ppm. This finding implies that the contemporary terrestrial biosphere is more CO2 limited that previously thought”
Ying Sun et al. 2014
“Impact of mesophyll diffusion on estimated global land CO2 fertilization”
Ying Sun, Lianhong Gu, Robert E. Dickinson, Richard J Norby, Stephen G Pallardy, Forrest M Hoffman
doi: 10.1073/pnas.1418075111
http://www.pnas.org/content/early/2014/10/10/1418075111.short
http://www.pnas.org/content/early/2014/10/10/1418075111.accessible-long
A special note, the authors comment about model deficiencies: “In C3 plants, CO2 concentrations drop considerably along mesophyll diffusion pathways from substomatal cavities to chloroplasts where CO2 assimilation occurs. Global carbon cycle models have not explicitly represented this internal drawdown and therefore overestimate CO2 available for carboxylation and underestimate photosynthetic responsiveness to atmospheric CO2.”
Jun 2013: “Satellite observations reveal a greening of the globe over recent decades. The role in this greening of the “CO2 fertilization” effect—the enhancement of photosynthesis due to rising CO2 levels—is yet to be established. The direct CO2 effect on vegetation should be most clearly expressed in warm, arid environments where water is the dominant limit to vegetation growth. Using gas exchange theory, we predict that the 14% increase in atmospheric CO2 (1982–2010) led to a 5 to 10% increase in green foliage cover in warm, arid environments. Satellite observations, analyzed to remove the effect of variations in precipitation, show that [green vegitation] cover across these environments has increased by 11%. Our results confirm that the anticipated CO2 fertilization effect is occurring alongside ongoing anthropogenic perturbations to the carbon cycle and that the fertilization effect is now a significant land surface process.”
[Note, others have published results in humid areas, like the Amazon rain forest.] “Satellite observations, analyzed to remove the effect of variations in precipitation, show that [green vegitation] cover across these environments has increased by 11%. Our results confirm that the anticipated CO2 fertilization effect is occurring alongside ongoing anthropogenic perturbations to the carbon cycle, and that the fertilization effect is now a significant land surface process.” “…it has proven difficult to isolate the direct biochemical role of[increases in atmospheric CO2 concentrations] in these trends, from variations in other key resources (such as light, water, nutrients [Field et al., 1992]) and from socioeconomic factors, such as land use change [Houghton, 2003].”
Donohue, Randall J., et al. “Impact of CO2 fertilization on maximum foliage cover across the globe’s warm, arid environments.” Geophysical Research Letters 40.12 (2013): 3031-3035.
http://xa.yimg.com/kq/groups/18383638/1708677228/name/grl50563.pdf
PDF link in article: https://groups.yahoo.com/neo/groups/26thIAE/conversations/topics/3529
http://onlinelibrary.wiley.com/doi/10.1002/grl.50563/abstract
…So, while global temperatures have not risen since the turn of the millennium, noticeable changes in vegetation are evident. As stated, the results were not limited to Australia, the researchers found that arid areas all over the globe were reaping the carbon dioxide bounty, as shown in the map below.
“On the face of it, elevated CO2 boosting the foliage in dry country is good news and could assist forestry and agriculture in such areas; however there will be secondary effects that are likely to influence water availability, the carbon cycle, fire regimes and biodiversity, for example,” Dr Donohue said.
This research does not mean that all the world’s deserts are suddenly springing into bloom, but in the affected areas an 11% increase in plant cover was found…”
“we predict that the 14% increase in atmospheric CO2 (1982–2010) led to a 5 to 10% increase in green foliage cover in warm, arid environments. Satellite observations, analyzed to remove the effect of variations in precipitation, show that [green vegitation] cover across these environments has increased by 11%.”
Donohue, Randall J., et al. “Impact of CO2 fertilization on maximum foliage cover across the globe’s warm, arid environments.” Geophysical Research Letters 40.12 (2013): 3031-3035.
[PDF] from yimg.com
Rather than attribute the greening observation to CO2-influenced fertilization of plant growth, Ranga attributes the greening to “… warmer temperatures [that] have promoted increases in plant growth during summer” “…the global carbon cycle has responded to interannual fluctuations in surface air temperature…” Oh wait, is he saying that the warmer temperature produced more CO2? Like from ocean outgassing? Anyway, he presents the point that accelerated plant growth has sequestered carbon from the atmosphere: “plant growth … net primary production increased 6% (3.4 petagrams of carbon over 18 years)” “Amazon rain forests accounted for 42% of the global increase in net primary production, owing mainly to decreased cloud cover and the resulting increase in solar radiation.” Note, Ranga is taking about increases in plant productivity in the Amazon rain forest, while others have emphasized plant growth in arid areas.
Myneni, Ranga B., et al. “Increased plant growth in the northern high latitudes from 1981 to 1991.” Nature 386.6626 (1997): 698-702.
http://ecocast.arc.nasa.gov/pubs/pdfs/1997/Myneni_Nature.pdf
http://www.ias.sdsmt.edu/STAFF/INDOFLUX/Presentations/14.07.06/session1/myneni-talk.pdf
These scientists study “…a hyper-arid land- locked region in northwest China” and observe that the
“…mean growing season vegetation cover has increased from 3.4% in 2000 to 4.5% in 2012.” They think the increased plant productivity is “…associated with increases in regional precipitation.” “We found that the regional fractional vegetation cover fV in the downstream parts of the greater Heihe River basin increased by 25% from 2000 to 2012.”
So much for dry regions getting drier, a mantra of the “Global Warming” crowd.
Wang, Y., et al. “Attribution of satellite-observed vegetation trends in a hyper-arid region of the Heihe River basin, Western China.” Hydrology and Earth System Sciences 18.9 (2014): 3499-3509.
http://www.hydrol-earth-syst-sci.net/18/3499/2014/hess-18-3499-2014.pdf
“Norway spruce and European beech exhibit significantly faster tree growth (+32 to 77%), stand volume growth (+10 to 30%) and standing stock accumulation (+6 to 7%) than in 1960. … mainly the rise in temperature and extended growing seasons contribute to increased growth acceleration …” The 14% increase in atmospheric CO2 (1982–2010) world-wide was not a controlled variable in this study, and its effect was ignored. This study attributes all of the increased productivity to the rise in temperature, and the resultant increase in the growing season.Pretzsch, Hans, et al. “Forest stand growth dynamics in Central Europe have accelerated since 1870.” Nature communications 5 (2014).
http://www.nature.com/ncomms/2014/140912/ncomms5967/full/ncomms5967.html
“… stimulatory effect of atmospheric CO2 enrichment is strongly temperature dependent. … for a 3°C increase in mean surface air temperature … the growth enhancement factor … rises from 1.30to 1.56.” That is a 30% increase, rising up to a 56% increase for a 3°C warmer environment.
Idso, S. B., et al. “Effects of atmospheric CO2 enrichment on plant growth: the interactive role of air temperature.” Agriculture, ecosystems & environment 20.1 (1987): 1-10.
http://www.sciencedirect.com/science/article/pii/0167880987900235
Willis replied: “While there is energy stored by plants, it’s basically a zero-sum game due to the energy released when the plants die and decay. Overall the two balance each other out.”
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How can it possibly be a zero sum game? Is Willis seriously suggesting that growing a tree requires no net energy?
During the life cycle of a tree, it has to overcome gravity. Not only does it have to build a vertical structure may be 25 or more metres high, but it also has to continally ‘pump’ water from below groud level up to the top of its canopy. This must take a lot of energy.
At most, all one receives back when the tree dies, is the mass of material in its structure. One does not get back the energy that was used in the organisation of that structure and its maintenance over the years.
A considerable amount of energy from sunlight must surely be ‘lost’ in the bioshpere.
richard verney February 23, 2015 at 9:59 pm
“Lost” in the biosphere? One of the first things we learn in science is that energy is neither created nor destroyed. So it’s not “lost” in any sense of the world. It just gets transformed into a different form of energy.
The energy utilized by the tree goes into a couple of forms. One, as you point out, is mechanical motion—pumping water up from the ground is a good example. However, that energy is not “lost” somewhere. It’s transformed into both potential energy (water up high has more potential energy than water at ground level) and also into heat (since all mechanical processes are less than 100% efficient).
So while you are right that there is energy expended in “the organisation of that structure and its maintenance over the years”, at the end of the day all of that energy will inevitably turn into heat and be returned to the environment. It won’t get “lost in the biosphere”. By the time that the tree dies and rots back into its elementary constituents, exactly as much energy as was put in during the lifetime of the tree will have come back out again as heat.
Best regards,
w.
Willis, I really learned a lot from your article and the thoughtful responses made by so many familiar names here.
My take on this stems from not eyeballing an increase in trend from 2000-2014 in any of the datasets you plotted, that correspond to the 8% CO2 concentration increase from 2000 to now. Do any of the data you plotted have an upward trend for that period?
I used co2now.org/images/stories/data/co2-mlo-monthly-noaa-esrl.xls, where for 2000 CO2 was 369.52 and for 2014 it ended at 398.55 (annual data).
What does that mean to you or anyone else if there isn’t a corresponding trend in these energy fluxes wrt the CO2 trend? Thanks and that is all.
The answer to my question was covered here last year: http://wattsupwiththat.com/2014/01/13/co2-and-ceres/ where you said “There is no trend (0.01 W/m2 per decade) in the surface downwelling radiation.” Thanks.
Your figure 2 there clearly shows the dropoff in TOA solar after SC23 max in 2003, bottoming out during the minimum in 2008-9, and thereafter increasing again as SC24 reached maximum.
I realize this post is a different subject, so please forgive for going off thread. At this time it’s pretty obvious to me anyway that surface downwelling radiation had nothing to do with the coincident 8% CO2 increase.