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Comments 26451 to 26500:
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scaddenp at 08:12 AM on 10 December 2015How much does animal agriculture and eating meat contribute to global warming?
Sorry, but you are making assertions that not at all supported by the literature. (Ch6 of IPCC AR5 WG1 is index into this).
"AGW methane increases are mostly from mining, natural gas, fracking, melting methane clathrates, melting permafrost etc..." -
Um, no they are not. Those account for <30%. Expansion of paddy and ruminant no.s are the main contributors. Globally megafauna skyrocketed after industrial revolution from 0.2E12 kg to 1.4E12kg (here, fig 5).
Of course methane was produced from animals pre-human even, but it is the vast increase in no.s post industrial rev that is the anthropogenic part of emissions.
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ryland at 08:08 AM on 10 December 2015Betting against global warming is a sure way to lose money
Tom Curtis. You clearly never have heard the phrase "perception is reality." The point I'm making has nothing at all to do with the data per se but only to the perceptions of "foul play" that alterations to the data might have caused. I hope I have now made that clear to you. And I'm not saying or even insinuating there was any foul play. As the altered data showed warming the cool bettor could be suspicious of the result and had it shown cooling the warm bettots might have had their suspicions.
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RedBaron at 07:46 AM on 10 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp
Not just bison also elk deer moose bighorn sheep antelope over 40 extinct species of megafauna, prairie dogs, extinct species of grasshoppers and on and on. You are reading Vegan "exterminate the evil cow" unholy alliance with AGW deniers propaganda again.
But at least you did say at the end "cattle in feedlots". Feedlots being the key component that actually at least is part of AGW.
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RedBaron at 07:34 AM on 10 December 2015How much does animal agriculture and eating meat contribute to global warming?
No no no it is not the lions share. It's not even the cow. Rather in so much as the little bit that did increase is related to animal husbandry, it is the methods by which those cows are raised. AGW methane increases are mostly from mining, natural gas, fracking, melting methane clathrates, melting permafrost etc... Even in agriculture, the haber process nitrogen we spread on fields killing over 70% of the methanotrophs (the only biotic methane sink) has a larger effect than the cow.
I guess you are going to have to trust me on this, because I can't find a scientific study that explicitly states it, but even before mankind existed as a species, animals were belching, farting, breathing and rotting after they died. All of which is "emissions" by that AGW denialist rhetoric.
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scaddenp at 06:27 AM on 10 December 2015How much does animal agriculture and eating meat contribute to global warming?
Everything is AGW is really compared to pre-industrial. Methane concentration in the atmosphere has more than doubled since pre-industrial (0.8 to 1.85) with increase in ruminants taking the lion share. As you point out, CH4 is short-lived so this represented substantial, sustained change of flux. The GWP for methane used to calculate CO2e takes into account the lifespan of CH4 in atmosphere.
Just looking at US rangeland, you think that change from 30M bison (emitting 72g/d CH4) to 90M cattle (emitting 170-240g/d CH4) really supports "methane from ruminants contribute nothing to the current AGW,"? The Follet et al 2001 reference above also notes overall loss of SOC since settlement. This report puts cattle in feedlots at 14%
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Tom Curtis at 01:44 AM on 10 December 2015Betting against global warming is a sure way to lose money
Knaugle, using WoodforTrees, the relevant means for RSS are:
1994-2004: 0.196
2000-2010: 0.225
2004-Current: 0.239
2005-Curent: 0.242
I have included the last as a better approximation to a decadal value.
In any event, with RSS it remains a clear win for the 'warmists', although the margins are not as large.
As an aside, the bet was that each period would be warmer, with a payout to Keenlyside et al if temperatures were tied (had they taken the bet).
As is so often the case with ryland's comments, he adopts a position that retains its reasonableness only by scrupulously not looking at the data. If you play unfair and look at the data, you find all he is left with is empty rhetoric.
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Pete12981 at 01:34 AM on 10 December 2015Sea level is not rising
I wonder how Monkton or anyone with a graph they believe disproves rise would care to explain how come the North Norfolk coast is getting increasingly flooded from the North Sea, and the golf course at Brancaster, just to cite one place, is expecting to lose its course by 2020 as it's close to the sea with just dunes protecting. And as no houses on the seaward side of the coast road can get mortgages.
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Pete12981 at 01:28 AM on 10 December 2015Sea level is not rising
Something has been bothering me for a while, but I've found no mentions in the literature. Maybe someone here has knowledge.
We know with increasing storms and precipitation causing massive flooding, landslides and topsoil degrading, the latter is talked about as harming agriculture. All the soil washed away eventually ends up in rivers and then the sea. It has volume, it is increasing. Archimedes?
Is anyone attempting to estimate the volume of loss and its effect on sea level rise added to all the other causes we know about? There are figures for soil loss annually, which one site claimed was the size of Wales, but no volumes and I know nothing about soil scince or erosion. However small, it's bound to add. Additionally, there's coastal erosion which is also adding annually to the eureka effect.
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knaugle at 23:59 PM on 9 December 2015Betting against global warming is a sure way to lose money
With respect to ryland's comment, looking at Cowtan's temperature plotter and the RSS data since 1994, it is slightly possible that the Real Climate folk would have won that bet as well. Remember the bet was1. 2000-2010 >= 1994-2004 and
2. 2005-2015 >= 1994-2004While it is certainly true some (like Ted Cruz) can point to RSS data and say "no warming" the past 18 years, even RSS clearly shows "no cooling" as well, certainly since 1994. The El Nino years in 2010 and present certainly balance the massive one in 1998 and the period 2001 to 2007 works to the advantage of the Real Climate folk.
So far as Ryland's altered horse track comment, note that RSS does not seem to publish version numbers, but I would be surprised if their methods have been locked in stone since 1994. UAH on the other hand is far more open. Their version 5.6 was much more in agreement with the surface data sets, but version 6.0 moved its data significantly in the direction of RSS data. THAT as well is an altered horse track.
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Kevin C at 23:05 PM on 9 December 2015Betting against global warming is a sure way to lose money
OK, here are the results using both the previous SST dataset (ERSSTv3b), and the one before that (HadR2):
1994-2004 2000-2010 2004-2015
ERSSTv3b 0.492 0.591 0.619
HadR2 0.458 0.557 0.589
SkS 0.451 0.553 0.587I took the dates from the RC post, which claims they are decadal. However the last period seems to be an unusual 11-year decade.
If you want to go further the next step would be to use the SkS temperature calculator to calculate a pure unadjusted record from HadSST3-unadjusted and GHCN-unadjusted. That way we can ensure that no changes in adjustment or calculation method play a role. I've listed those in the final row of the table.I'm not endorsing those numbers - Zeke and I have already provided two independent analyses supporting the existence of a cool bias in the SSTs over the period. They should therefore be treated as a lower bound on the warming over that period.
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RedBaron at 22:19 PM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp
I slept on it and I think I figured our why we are at odds. I believe it is a failure to communicate and I am willing to take the blame. I really failed to express to you what I mean by "net sink". Obviously there is always going to be some methane entering the atmosphere. But we are talking about AGW. In other words how humans have effected that cycle. So when I say net with regards to methane it means something different than when I say net with regards to carbon dioxide.
Methane from animals is the short cycle. There always was and always will be emissions of methane from the short cycle, just replacing what gets oxidized abiotically. So because methane has such a short 1/2 life in the atmosphere, to actually be a cause of AGW, the emissions rate would have to exceed pre industrial emissions rates. Anything with a lower emissions rate than that can be seen as a net reduction. That doesn't mean no emissions, just less emissions. For that reason methane from ruminants contribute nothing to the current AGW, but rather the factory farm production model that removed those ruminants from the land.
This is different than CO2, because CO2 is stable in the atmosphere. It basically does not oxidize abiotically.
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Eclectic at 21:41 PM on 9 December 2015Betting against global warming is a sure way to lose money
Let's hope "the bet" outcome will not be much different, for old versus new, on the Cowtan Totalisator.
I'm expecting that the [Ryland] horse racetrack length will have suffered only a few metres' alteration in toto, over the years. Not enough to worry any genuine punter, anyway.
Plus, we have already witnessed the cumulative race results in recent decades . . . and the stewards have confirmed the results :- It's getting warmer. No pawse, just hoofbeats ~ and let's pray it is not the biblical four horse race :-)
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Kevin C at 21:04 PM on 9 December 2015Betting against global warming is a sure way to lose money
Fortunately GISS still distribute the ERSSTv3b grids, and the software to blend them into a land-ocean record. They're at the bottom of this page. Look for the link labelled "Sea surface air temperature (ERSSTv3b), previously used". So we can easily find out whether the bet would also have been won with the old GISTEMP.
I've got the calculations running now.
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ryland at 20:25 PM on 9 December 2015Betting against global warming is a sure way to lose money
To forestall any criticism, let me say upfront I don't believe alterations to temperature records have been made solely to hide a "hiatus" or "pause "or exaggerate a warming trend. A question-was the bet based on temperature calculations from satellite measurement or ground station observations? In view of the adjustments that have been made to temperature readings for whatever reason, it is probably a good thing the bet was not made. Adjustments to temperature records which did occur after the bet had been suggested, would and quite rightly should, have raised doubts in all of those placing the bet whatever the temperature trend showed. A bit like having a bet on a horse only to find finding the track had been altered after the bet had been placed but before the race had been run.
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scaddenp at 18:54 PM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
foolonthehill. I dont have NZ no.s but grazing/farmland in US takes up CH4 at <1.5kg/ha/yr (the del Grosso reference). 226g/head/day is 82.5kg/head so you should be able to work out from your stocking rate /ha. (which is what by the way? I found it very hard to get info on US stock rates which seem to be 0.2-0.3 on rangeland. NZ intensive dairy goes to 3.5-4 I think.)
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scaddenp at 18:45 PM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
Redbaron, your conjectures are not supported by the actual measured methane oxidation rates, nor (so far) by actual measurements of SOC increase. No SOC increase, no sequestration. Now the results I had were from survey of NZ soils. Prairie soils are a different beast so if you can find comparable multi-decade survey showing SOC rates big enough to offset the number of ruminants, then I would be delighted to see it. The best I could find was Follet et al 2001.
This notes the issue with intensity
" light stocking intensities (1.2 AUM/ha) did not have any effect on the SOC content after 44 years of grazing; however, heavy (2.4 AUM/ha) and very heavy (4.8 AUM/ha) grazing significantly reduced the SOC in the foothills of southwestern Alberta. They believe the heavy grazing intensities “jeopardized the sustainability of the ecosystemby reducing the fertility and water holding capacity."
However, the study mostly considers the potential for increasing SOC and its recommendations for practise look truly excellent. Overall,
"We estimated ... that 10.2Mha of U.S. pastures use improved grazing management systems, with sequestration rates of 300 to 1300 kg C/ha/yr and total sequestration of 3.1 to 13.3 MMTC/yr. "
While this is good news, a dry-cattle low-end emission is 170g CH4/day, = 62kg/year or =1737 kg Co2e/year. So the stocking rate is vital. 0.29 head per ha is 500kg CO2e/ha/yr. At that rate, SOC can keep ahead. No way if stocking rate is even 1/ha. Increased SOC seemed to come from better grazing management, fertilizer and water inputs which I would also associate with higher stocking.
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Tom Curtis at 18:39 PM on 9 December 2015Scientists' open letter to the Wall Street Journal re: Ridley and Peiser
Charlie A @51 draws attention to three purported sources of "erroneous conversion from emissions to forcing", one of which (different estimate of radiative forcing relative to change of concentration) is valid and is discussed at 48 above. It represents an 18% overestimate of FAR radiative forcing for change in concentration relative to current estimates for CO2 forcing, although less than that for all WMGHG. It is the major factor as to why scenario B rather than scenario D is the closest relevant factor.
To that valid concern, he adds two specious concerns. The first is an assumed overestimate of the retained fraction of CO2 in the atmosphere. However, the IPCC FAR BAU scenario represents a retained fraction of 55% of the specified emissions. Those emissions are industrial emissions, as argued @48 above, for which the retained fraction on modern observations is also 55%. The retained fraction would be too high if (and only if) the CO2 emissions specified in the scenarios were intended to be the combined industrial plus LUC emissions, a possibility contradicted by the fact that the states emissions in 1990 are well less than the combined emissions averaged over the preceding decade as specifice in the FAR.
The second specious concern is that the model used for the prediction did not incorporate aerosols as a forcing. That could be a valid concern if anthropogenic aerosol forcings increased significantly from 1990-2015. Unfortunately I cannot test that, but from the IPPC AR5 Figure 8-18 (below), it can be seen that anthropogenic forcings in addition to WMGHG has decreased by 2.4%. Furthermore, overall forcings have decreased relative to WMGHG as well. The IPCC FAR included only anthropogenic WMGHG because rates of change in other anthropogenic forcings, and in natural forcings, was expected to be small relative to anthropogenic WMGHG, a supposition born out by AR5 data.
Finally, Charlie A lets forth with a rhetorical cannard, suggesting we are comparing IPCC FAR predictions by applying their two box model to historical forcings. Of course, nothing is further from the truth. What we are doing is comparing historical forcings to the four IPCC scenarios to see which one most closely matches history. That is what we are supposed to do. That is the whole point of constructing different scenarios and generating a range of projections instead of just one prediction.
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MA Rodger at 18:22 PM on 9 December 2015Scientists' open letter to the Wall Street Journal re: Ridley and Peiser
Charlie A @51.
You actually signal four objections to the FAR. Objecting to the abilities of the FAR climate models to provide anything useful does rather trump all that goes before. Do you feel the predictive abilities achieved by FAR to date are then just coincidental?
But let us be "instructive" and begin by addressing initially your first point. The Airborne Fraction AF (as it is referred to these days) has remained remarkably steady over period of Atmospheric CO2 instrument data, something that wasn't that clear a quarter of a century ago. Another difficulty facing the FAR was the emissions from LUC which they greatly underestimated. Thus the numbers used to calculate the AF were not the ones we would use today and would indeed suggest a rising AF. However, these data problems do cancel each other out over initial decades.
Also note that the FAR did not begin by defining emissions. That was not a part of the "Task A" brief required of WGIII whic was more to check that the climate forcings in their brief were realistic. Some of the numbers they considered were extreme by today's standards but those were generally averaged out of the final scenarios.
Given this situation, your position on this first point is not clear. Are you then actually arguing that the scenarios, presumably specifically Scenario A is some form of straw man?
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Charlie A at 17:12 PM on 9 December 2015Scientists' open letter to the Wall Street Journal re: Ridley and Peiser
#49 MA Roger. "you suggest there was "erroneous conversion from emissions to forcing" within the FAR scnarios. Could you expand on that comment?"
1. Errors in calculating concentrations that result from given emissions.
I have not calculated the specific impact of this, but it appears that FAR overestimated the fraction of anthropogenic CO2 that would remain the atmosphere.
2. Errors in calculating radiative forcing for given concentrations Is CO2 radiative forcing 3.7W/m2/doubling or is it 4.3W/m2/doubling. Obviously, if one uses 4.3 (as did FAR) instead of 3.7 one calculates higher forcings than if one uses the currently accepted 3.7 number.
3. Ignoring aerosols. Yes, FAR radiative forcing calculations completely ignored aerosols. I have not caclulated the specific impact of this. In 1990 the was uncertainty as to whether aerosols were even a positive or negative forcing: "In view of the above uncertainties on the sign, the affected area and the temporal trend of the direct impact of aerosols, we are unable to estimate the change in forcing due to troposphenc aerosols. " Page64 FAR WG1, forcing chapter.
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The goal of governmental policies are to control emissions, since that is the human "input" to the ecosystem.
First, from emissions we make assumptions, and calculate concentrations. Secondly, from those calculated concentrations we then calculate radiative forcings. In a third step, from the radiative forcings we then calculate expected temperature changes.
While it is instructive to ignore errors in the first two steps and then see if the calculations from forcings to temperature changes are correct, it sheds very little light on the overall accuracy of FAR predictions/projections. This is particularly true since the FAR predictions are the output of a simple 2 box model. While many seem to assume that the GCMs were used to make the FAR predictions, in reality they were done by an extremely simple two box model.
Provided that I get to choose my forcings, I can do a very accurate projection of global temperatures using a simple multiplier and a single exponential lag. Even the two box model is overkill. Of course, my projections become exceedingly accurate if I get to adjust the forcings to those observed, as others have done in their comments.
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Some further details, .....
A crude examination of assumed emissions vs project PPM CO2 leads me to believe that FAR assumed higher percentage of anthropogenic CO2 would remain in the atmosphere than actually remained. I haven't bothered to see where the discrepancy comes from, but I did note that the FAR expected a "saturation effect" to take place which would lead to a rise in the percentage of anthropgenic CO2 remaining in the atmosphere (about 1/2 stays in atmosphere and 1/2 is absorbed into biosphere and oceans).
Another error is simply the radiative forcing formula used for CO2. Yes, this is basic physics, but the consensus has changed as to the correct value. For example, the TAR (2001) uses delta-F = 5.35ln(C/C0). (This leads to the more often used 3.7W/m2/doubling of CO2)
In 1990 the FAR used delta-F = 6.2ln(C/C0).
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foolonthehill at 16:15 PM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
This is why they are superior at soil building to other types of herbivores.
Until the arrival of cattle in 1814, New Zealand was devoid of ruminants. Would you expect our soils to be low in carbon? Do you think that the arrival of cattle would have improved the carbon content of our soils? Bear in mind that our cattle are almost all pasture fed and always have been.
The measured amount of enteric methane release from 26 month old steers in New Zealand averages 222g per head per day. Could you give me a percentage of this methane that you think is being consumed by the methanotrophs and converted into soil carbon. I know my stock numbers so if it is all being captured at source I should be able to get a handle on how much my soil carbon mass will increase by.
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RedBaron at 15:07 PM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
OK great. Now for an even bigger factor, pore space in the soil. This is the habitat the actual methanotrophs colonize. As that surface area increases it both increases the habitat for the methanotrophs and increases the flow of methane from the atmosphere to them by increasing the aeration of the soil. The entire soil food web including all the animals, worms, plants, fungi, other soil biota etc can either positively effect that pore space or negatively effect it. As a general rule the more living biomass, the more improvement in soil pore space. Every bit of that living biomass has it's role to play from the predator to the herbivore to the plant to the soil biota. The role of the ruminant is to rapidly start the break down of plant material that is resistant to decay. By rapidly starting that process, which is finished by other trophic levels, it increases that cycle rate, increasing the growth rate of all. A ruminant can do in a day what would take at least a month or more to happen without the cellulolytic microbes found in a rumen, and they leave plenty of food available for everything else. This is why they are superior at soil building to other types of herbivores. The emergent property is that even though the emissions increases, so does sequestration, compared to the biome without a ruminant to start that process of decay. Now it doesn't actually need to be a ruminant, but the advantage a ruminant that makes them even better is that they actually extract comparatively little from that forage. When they start the process, there is an abundance of energy still available for the other trophic levels by compareson. That filters all the way down through the entire soil food web, including those parts responsible creating pore space.
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scaddenp at 13:40 PM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
Okay, I agree that you get more methane oxidation from soils closer to the animal. That still doesnt deal with issue that amount of oxidation/absorption is small compared to emissions. Assuming no methane capture at all in feedlots, that would increase net methane by 1% cf to same animal in grasslands. (Actually more complex than that because feed is different).
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RedBaron at 12:53 PM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp
OK I will walk you through it. From the previous review I gave you: ROLE OF MICROORGANISMS AS CONTROLLERS OF TRACE GAS FLUXES.
"In most upland soils, CH4 production is usually absent or marginal and the CH4 flux is dominated by CH4 oxidation."
Then a discussion about why and exceptions. Then:
"The subsurface location of methanotrophs means that energy
requirements for maintenance and growth are obtained from
CH4 concentrations that are lower than atmospheric."By Fick's laws of diffusion methane from a higher concentration will move to the lower concentration. There it will be used by the methanotrophs for energy requirements, keeping the concentration low. So there is a steady flow unless blocked in some way. Upland soils are generally well aerated. Of course management can effect this, but generally where there is a healthy population of earthworms, arthropods, insects etc.... the soil will be well aerated. So in those healthy soils you have a flow from higher methane concentration to lower methane concentration. As long as the other environmental factors don't restrict it, the methanotroph population will grow rapidly as the flow of methane increases, increasing biotic oxidation proportionately.
But as wideEyedPupil observed, spacial relationships do matter. You can get a flow from the cow to the soil if the cow is right there. Even easier to get a flow from the manure since it is even closer. But you cant get much of a flow from many miles down the road at the feedlot. Also locally at the feedlot, the large concentration of animals constantly there overwhelms the ability for those soils to keep up.
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scaddenp at 11:53 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
Hmm, well firstly, the soil doesnt actually remove much of the airborne methane anyway according del Grosso. Secondly, methane becomes very quickly well mixed gas so soil around the feedlot would do it's bit. I am not convinced that grasslands with ruminants were ever net sinks for methane. CO2 equivalents, yes, thanks to increase in SOC from plant material, but not for just methane.
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RedBaron at 11:20 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
@wideEyedPupil
Absolutely I agree with you observation that spacial relationships matter. Now go from 8" to 8' to 80 miles and you see the problem with the feedlot production model and why what was a methane sink turned into a methane source. One can understand the enteric methane emissions mixing with the atmosphere near the soil surface, but remove those animals from close contact with the soil and you break the link. For the grazer/grassland biome as a whole to be viewed as a sink, those grazers absolutely must be in direct contact with the grassland. What does escape due to being lighter than many other gasses in the atmosphere and diffusing upwards, subject to abiotic oxidation. But in a feedlot the majority of emissions do count as a source. So I am not disputing the IPCCs view currently, only adding the refinement that shows how this can be changed.
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wideEyedPupil at 10:54 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
@redbaron
8" —> 8 feet
you are climaing that in this study you refer to and I'm yet to read that all enteric fermentation dervived methane never enters the atmosphere because it is locked up in soil biota (given a particular pasture managmanet system). Methane being a gas that is lighter than many other gases in the atmosphere it's going to rise, to suggest that 100% is trapped in the soil when it's being breathed out ~1 meter above the soil is counter-intutative to me. I use that phrase because I'm sure it's music to *your* ears :-) -
scaddenp at 10:53 AM on 9 December 2015There is no consensus
What you should be looking for is "stratospheric cooling". It is not an easily understood concept, but there are several attempts around the internet to explain it. At basic level, It falls out of the equations for radiative transfer if you increase a greenhouse gas. Other forcings that change the surface temperature like changing albedo, solar influx, or aerosols do not produce this effect.
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scaddenp at 10:43 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
Redbaron, this still avoids the main points.
1/ microbial soil activity in changing CH4 is insignificant compared to enteric emissions. The very highest rates of CH4 soil oxidation measured by Del Grosso are still an order of magnitude less than ruminant emissions. 2 orders of magnitude for grassland. Are you disputing that measurment? Your reference appears to be hopelessly dated compared to modern sources (eg see the methane cycle in the IPCC from 3rd report onward and the references from which this table is based).
2/ If you want to argue for soils being significant in sinks, then SOC must be demonstrated to be increasing. No matter how complex the interactions going in soil/atmosphere, if SOC is decreasing, then soil is not a sink. Furthermore soil oxidization only accounts 5% of methane destruction so hardly a "controlling" influence.
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wideEyedPupil at 10:42 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
@redbaron
thanks for the responce. I'm quite aware of emergent behaviors in complex systems (and the modeling of such phenomena in theoretical computational simulations), and the general complicatedness in addition to the complextiy of soil biota and any biological systems above the ground that might be active on it and therefore interacting with biota.
as someone challanging the dedicated work of the Land Use Plan that puts land use sector at 55% of emissions (and I've never heard that number challenged in the literature) i think the onus is on you to demonstrate any complexity that undermines 55% of total emissions with data and evidence — the rallying of phrases like emergence, complexity and reductionist science is no doubt music to my ears but data and specifics it is not.
you seem to find a way to build condencension into every second para but what I want to see is evidence, not defensive assessments of whether or not I 'get' your riddles. I understand the importance of soil biota and not destroying the surface vegetation in protecting the soil biota. I understand that your exmaple of ten fat cows and five skinny cows is designed to impress on one the problem of overgrazing (even though intensive over-grazing and recovery is exactly what Savory advocates so you gloss that detail too) but you forgot to I've read a tiny bit of everything from Masanobu Fukuoka's "The One-Straw Revolution" to Permiculture One to sitting in some of Dr Eliane Inghams (USA/Australian biota and fungi expert) online lectures and watched "One-Cow One-Planet".
I've visited many properties where overgrazing is a conceeded fact and others where the reverse is happening e.g. a biodynamic berry farm where the green manure crop of barley was reaching 8" high and still growing. It's clear increasing soil health increases 'carrying' capacity of the land when bio-diversity is encouraged in principle at a sytems thinking level rather than reductive Green Revolution type ag-disaster industrial farming.
But all that is not a substantive proof that methane is neutralised nor is it evidence that intensive grassing on rotational basis is vastly more productive, or indeed that animal intensive agriculture is a prefered responce to climate change. I'm reading a lot of commentary and philospohising in your posts and not much science. Thanks for the references I'l attempt to comprehend the work and get back to you on the science. -
RedBaron at 10:19 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp
I guess maybe where you are struggling is the concept of soil microorganisms as a controller of atmospheric trace gasses. Without that foundational understanding, any new studies lack the contextual relationship for you to understand. So to help you understand, I found an old review from 1996 that explains what we knew and didn't know about how soil biology controlls atmospheric trace gasses at that time. This maybe will give you the context needed to understand how new discoveries are unlocking the mechanisms by which the grazer/grassland biome taken as a whole functions as a methane sink and not an emissions source....managed properly of course.
Soil Microorganisms as Controllers of Atmospheric Trace Gases
(H2, CO, CH4, OCS, N2O, and NO) -
wideEyedPupil at 10:11 AM on 9 December 2015There is no consensus
Thanks for Responce @Rob P and for the link to Climate Cluedo. I get that carbon isotopes are critical in determining CO2 sources and ways of determining concentrations but my question speicifically was what is it about a cooling upper atmosphere in conjunction with a warming lower atmosphere that is unique. Another way to ask this might be, why is the upper atmosphere cooling with increased GHG levels while the lower atmosphere continues to rise at a sharp rate compared to background seasonal oscilations? And how do we know that in the past when the lower atmosphere warmed, so to did the upper atmospthere, or did it just stay the same. (I only found three hits on the Cluedo page when searching "upper atmos" and they were all in comments. no hits for "lower atmos")
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scaddenp at 09:43 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
Michael, I suspect the amount of time that you have available for animal management might be the overriding factor. Sheep need shearing (which is plus if you can get more for wool than cost of shearing), but fattening a few lambs might be good option. Goats climb and like eating things other than grass...
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scaddenp at 09:36 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
RedBaron, I am not disputing the reference. The release of methane to the atmosphere from agricultural use is mostly a/ paddy fields (where there is no oxidizing layer) b/ Enteric emissions from ruminants (nothing to do with soil microbial activity) plus some from manure.
I am just failing to understand how you are linking this idea to position that increasing ruminent intensity even on MIRG isnt putting more methane into the atmosphere. If microbial activity is binding more carbon into soil, then it should show up in SOC measurements. Mostly, we see the reverse - intensity = less SOC, or that enteric emissions overwhelm increased SOC.
And dont forget that areas with increased SOC are counted in GHG inventories. It's not like GHG emission strategists have missed something.
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RedBaron at 08:46 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp
You are definately missing the boat on methane. The reference says even though there was a "dramatic" increase in methane produced, "none" was released to the atmosphere. So other studies that simply measured emissions failed to account for this emergent property. Also I am well aware that current methods of agriculture most commonly used do release methane to the atmosphere. The reason I showed that the natural ecosystem functions as a sink, is because ecoagriculture uses biomimicry to mimic that ecosystem function already evolved in a natural ecosystem (grazer/grassland biome) in order to change what is currently an emissions source into a sink as well. A sink that self regulates. ie when when production of methane increases, none releases to the atmosphere because the biotic reduction of methane also increases. Go back and read that a little closer please. "Nevertheless, no CH4 was released". This is the perfect example of an unexpected emergent property of the system. And do keep in mind we are talking about aerobic soils managed in a certain way. They exchange gasses with the lower levels of the atmosphere ie they "breathe". The CH4 goes into the soil, but none is released. That's why it can be viewed as a sink under those conditions.
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michael sweet at 08:42 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
Scaddenp and Fool on the Hill,
Thank you for your interesting comments and references. I will have to think about methane and see what I can do to minimize my emissions. I have about one hectare of land that would support one or two cattle without suplimentary feed (or a comparable number of smaller animals). Currently there is a sizable population of rabbits that the local coyotes eat.
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scaddenp at 07:10 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
RedBaron, firstly we talking about effect of farming. The effect of grassland expansion on climate in Cenozoic is not that relevant compared to even pre-industrial farming.
If I understand you correctly, you are now saying that CH4 production from increased ruminant density is offset not only by SOC increase (yet to be demonstrated) but also by changes to CH4 sources/sinks in microbial soil activity? My first reaction is to be highly skeptical since biogenic methane budgets are estimated both top down and bottom up. While there is imperfect closure which might be accounted for from microbial changes, this cant be very significant.
Assuming I have understood your argument correctly, I do not really see support for this in your papers. "Methane fluxes from differentially managed grassland study plots: the important role of CH4 oxidation in grassland with a high potential for CH4 production" looked at changes with different fertilizer and water but as you stated, it found no increase in flux due to oxidation in top layer. How does this support your thesis of "large enough to completely offset the CH4 produced"?
The fluxes measured in the experiment are tiny compared to enteric emissions (0.0017g CH4/day cf 140-160 dry cattle).
Methane uptake in upland soils is acknowledged as a sink but the paper suggests to me that this capacity would damaged by agriculture. Indeed, it references del Grosso which surveyed methane oxidation across upland soils and concluded: "The soils used for model testing showed a clear division in CH4 uptake rates among biomes. Grassland and agricultural soils had the lowest annual CH 4 uptake (<1.5 kg C ha-1 yr-1), coniferous and tropical forests showed intermediate CH 4 consumption (1.2-3.5 kg C ha -1 yr-1), and deciduous forest soils had the highest CH4 oxidation rates (4.5-10 kg C ha-1 "
Note also that enteric methane production is at least an order a magnitude greater than highest oxidation rate.
I dont want to be critical of MIRG, especially compared to grain feedlots, but certainly dont see this as answer to CH4 emissions.
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scaddenp at 06:22 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
Michael Sweet, I looked at this quite a while ago and thought that for same amount of forage, production of methane per hectare was pretty similar between sheep and cattle. However, a review paper here suggest greater differentiation than this, with 10 sheep = 1 cow (and less CH4 from manure). This paper based on identical feed gives cattle lower, (8 sheep = 1 cow). I dont have figures for goats easily to hand but I remember them as being very similar to sheep. That said, there are very considerable differences in management of the 3 species for a small lot! Of course you could also look at rabbits or guinea pigs which are much better than ruminants ( but with completely different management and harvest issues).
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RedBaron at 01:57 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
@wideEyedPupil several posts
Your posts while thoughtful and well referenced do hilite the limitations of applying reductionist science to complex self regulating biological systems. Some of the things you talk about do partly take into account some of the unexpected emergent properties of the system, and some view it quite linearly. You really do need to be careful how you build back the reductionist science into a systems view.
Also you answered the riddle wrong, which means you haven't thought that out correctly either. So lets start with that. Overgrazed land produces less forage, less forage means it supports less animals, thus the correct answer is the overgrazed land is the one with 5 skinny cows. Properly managed land produces more forage. Much more. in the field we see 3X more forage, maybe 5X more forage, maybe more, it really depends how badly the land was overgrazed to begin with. The worse it was, the more improvement to be gained by proper management. So more forage means it supports more animals. The 10 fat cows are on the properly managed land in the riddle. I know it is counterintuitive, but once you think it through, hopefully you will understand.
Next, you said, "It's a while since I read it but because I was working with the principle authors I'm aware that they found sufficent evidence for them to reject the hypothesis often possed ... that oxidation of methane by water vapour above grass neutralises the effects enteric fermentation"
That's not the hypothesis, so rejecting that hypothesis doesn't really get you anywhere. That is describing abiotic oxidation. The hypothesis is the soil biota increases, including but not limited to methanotrophs. Increases in methane, in the right environmental conditions causes an explosion of methanotroph populations, and that is what biotically reduces the methane. Those environmental conditions that lead to the explosion of soil biota populations, including but not limited to methanotrophs, being enhanced in a properly managed grazing system. It's biotic, not abiotic.
Next you said, "Nobody has replicated the Savory assertions in a commercial livestock operation any place in the world in a study that can varify the claims around sequestration."
That isn't true. Maybe the ZCA Land Use Report couldn't find anything, but that doesn't mean it doesn't exist. I even posted one here that included several commercial scale ranches. At least I think I did. Just in case, here you go: [1] There are more even larger, but I don't think they have been published yet.
Next you said, "You make this assertion liberally but I can't find your citation 'up above', yet."
No problem. I repeated that citation and added some new in post #84, since people were having problems finding and/or understanding.
Next you said, "the technology to reduce the enteric fermentation in your cattle does exist, fed them some grain. various studies have looked at this and other inteventions. of course the grain also has emissions associated with it and if synthetic fertlizers have been used destruction of the soil biota and therefore short term carbon cycle is part and parcel their use."
This indicates to me you almost kinda understand. Just use that type of thinking, but expanded to include a wider array of emergent properties and interactions. More variables change than just the ones you mentioned and they all have interlocking interdependencies.
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Zambrall at 01:12 AM on 9 December 2015Analysis: the key announcements from Day 1 at COP21
I think that Obama is trying to do great things in the word like trying to help poor countries around the word. But he has not done anything in all time all he is doing is just sitting in the white house in his big chair and just watching the bad things that are happening to our country and not doing anything about it! So like my mom said that she can't watie untill obama is not the president any more. Did you know that my brother Robert is woring for him! That thing that had happen in paris I heard that he was just clebreating that he had just bomed the place were the bad people are and that is why the bad people had bomed paris. My mom also said that the only reason why they are doing this and hurting people is becasue Obama is a mulism. So why isnn't Obama doing anything to help our country.
Moderator Response:[PS]
Thank you for taking the time to share with us. Skeptical Science is a user forum wherein the science of climate change can be discussed from the standpoint of the science itself. Ideology and politics get checked at the keyboard.
Please take the time to review the Comments Policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
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wideEyedPupil at 00:50 AM on 9 December 2015There is no consensus
One of the human finger prints cited in the first week of the Denial course was that the atmospheric warming this century is unique in the fact of warming lower atmosphere and cooling upper atmosphere. What evidence from past warming episodes establises that this is unique to the current warming. How do we know what happened in the upper stmosphere in the past warming/ increased CO2 events?
Moderator Response:[Rob P] - A cooling upper atmosphere and warming lower atmosphere is a signature unique to the enhanced (increased) Greenhouse Effect. If we had a Tardis, we would be able to go back in time to the Paleoecene-Eocene Thermal Maximum (PETM) about 55-56 million years ago, a time of substantial natural global warming, and observe the Greenhouse Effect growing stronger.
The enhanced Greenhouse Effect we are now measuring is a human fingerprint because the source of it is the continued emission of greenhouse gases, primarily carbon dioxide, produced by industrial activity. See the SkS post: Climate Change Cluedo.
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wideEyedPupil at 00:43 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
#78 foolonthehill
the technology to reduce the enteric fermentation in your cattle does exist, fed them some grain. various studies have looked at this and other inteventions. of course the grain also has emissions associated with it and if synthetic fertlizers have been used destruction of the soil biota and therefore short term carbon cycle is part and parcel their use.
I recommend you download the (free) Zero Carbon Australia Land Use Plan as it covers every aspect of Land Use emissions and sequestrations in what I would describe as great detail for anybody who doesn't study emissions in ag system. -
wideEyedPupil at 00:27 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
#69
I would like a reference to that paper you refer to that demonstates ruminet ag is a net sink not a net source of emissions. Many permaculutralists repeat this assertion as an article of faith, so it's not like its a new one for me but I've never seen the convincing evidence and plenty to contradict it.
You make this assertion liberally but I can't find your citation 'up above', yet.
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wideEyedPupil at 00:24 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
#69
Every vegan I ever met except one was completely incapable of making the connection. But this is what needs to happen to turn agiculture from the net emissions source it is now to a net sink. It is also what needs to happen to reduce the deforestation that is happening to support animal husbandry.
I wonder if that's because you make a dubious anaolgy with ten fat cows and five skinny cows and make no attempt whatsoever to decribe any mechanism by which the overgrazing leads to fatter cows! Have they been there longer, were they rotated through fields, so many variables in farming and you talk of riddles. I assume you are attempting a paraphrasing of the Savory assertion, yet to confirmed with science in any commenrical farming system anywhere in the world.
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wideEyedPupil at 00:11 AM on 9 December 2015How much does animal agriculture and eating meat contribute to global warming?
From the systems science POV, when you remove the animal from the pasture and put them in a confinement system, you break part of the methane cycle, causing a nuanced chain of interactions with soil biota, quantifiably decreasing ecosystem function. Net result? You turn a net methane sink into a net methane emissions source. So it is very important to be very precise when discussing "intensive" agriculture. Managed Intensive Rotational Grazing is an intensive agriculture, but is very different than intensive agriculture reliant on expensive AGW causing inputs. Properly done, MIRG can actually help mitigate AGW, not cause it.
@RedbaronZCA Land Use Report specifically rejected this Alan Savory type argument. they found that dietry interventions can reduce methane emissions significant;y, but only can be used in lot feed systems, I've recently read that studies by diary industry have found that small amounts of grain feed eaten in the milking shed or afterwards can reduce enteric fermentaion by some significant amount but not entirely. Another thing they point out about Savory's assertions is that if you had farm workers moving temporay fences every day it would remove profitibility from the vast pasteral operations with large head counts that rarely see humans let alone get daily management in small mobile herds. Nobody has replicated the Savory assertions in a commercial livestock operation any place in the world in a study that can varify the claims around sequestration.
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wideEyedPupil at 23:58 PM on 8 December 2015How much does animal agriculture and eating meat contribute to global warming?
The Zero Carbon Australia Land Use Report published by Beyond Zero Emisisons and Melbourne Sustainable Society Instititue (University of Melbourne) pegged Land use emissions at 55% (using 20 year GWP) of Austrlia's national GHG emissions once complete examination of all flows of emissions and sequestration are accounted for. Their methodology went well beyond the methodology of UNFCCC specification that is typically used for these accounting exercises. Even using 100 yr GWP (which tends to obscure the effects of methane on a climate system that is already set for very dangerous weather) the emissions will approact 50% within years on present trend.
It's a while since I read it but because I was working with the principle authors I'm aware that they found sufficent evidence for them to reject the hypothesis often possed (the source of which is apparently a paper that contained an magnitude of ten error) that oxidation of methane by water vapour above grass neutralises the effects enteric fermentation (highest in pasture fed ruminets not lot animals as someone here seems to be claiming). Most cattle in Australia are lot fed for the last year or two of there lives to increase their weight for profit motive. They also rejected what is often refered to as the Alan Savory method by permiculutre types who like to think that zero emssions ruminent production is realsitic proposition. Of that 55% of national GHG emissions, emissions associated with livestock were calculated to be 90% i.e. 50% of national emissions associated with livestock production. Major emissions sources were land clearing, savanana burning and enteric fermentation.
The Land Use Report began a feasibility study of what kind of reforestation would be requierd in each IBRA Sub-region to offset the emissions assoicated with the predominant agriculutral use for the region.
it's interesting to me that this area of climate science is both one fo the least studied and one fo the most heatedly contested amoughst scientists and others who otherwise accept the general IPCC positions on human induced climate change (even if some of us think the IPCC has been ultra conservative in it's communication of the science).then you have scientist like Dr Elaine Ingham who claim vast potential for organic sequestration if we stoped killing our soils with synthetic fertilizers and exposeur to the sun. by vast she claims equivilent contemproaraeous to human emissions.
my understanding is that the ZCA Land Use Report was supervised within MSSI and peer reivewed, though its publication was by BZE and MSSI not in a journal.
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Tom Curtis at 23:25 PM on 8 December 2015Scientists' open letter to the Wall Street Journal re: Ridley and Peiser
Further to my post @48, based on Figure 9 of the IPCC FAR (below), the increase of temperture in 2015 relative to 1990 is 0.7 C for scenario A (BAU), 0.5 C for scenario B, and 0.4 C for scenario D. These in turn correspond to trends of 0.26, 0.18 and 0.17 C/decade respectively. The Gistemp trend from 1990 to current is 0.169 +/- 0.066 C per decade, ie, closest to scenario D but consistent with all scenarios except A. The less than global HadCRUT4 trend is 0.155 +/- 0.066 C/decade, ie, slightly undershooting scenario D but again fully consistent with all scenarios except A.
It becomes clear why Charlie A is so tenacious in insisting that scenario A is the only one that matters and the "IPCC prediction" despite the clear indication that it was relative to a particular scenario and other projections were also made. Absent the absurd idea that BAU for 1990 was actually what happened, it becomes clear that the 1990 temperature projections stack up very well relative to observations.
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RedBaron at 21:23 PM on 8 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp
OK Fair enough. Here is some evidence that leads me to believe it is not the ruminant at all, but rather the feedlot production system, including both the feedlot and the grainfields supporting the feedlot, and the petroleum derived chemical fertilizers supporting the grainfields, ie that whole "factory farming" system, that is to blame. Even when it comes to methane.
Starting with this comparing nitrogen fertilizers instead of organic fertilizers.
Environmental impacts on the diversity of methane-cycling microbes and their resultant function
"In a temperate agricultural soil, long-term fertilization with ammonium nitrate reduced methanotroph abundance by >70%, resulting a similar decline in methane oxidation rates (Maxfield et al., 2008; Seghers et al., 2003a) observed a similar pattern that was associated with reductions in the abundance of low-affinity type I methanotrophs. Different groups of methanotrophs may show different responses to fertilization, as observed in rice field and forest soils where type II methanotrophs were more strongly inhibited by mineral N fertilization than type I methanotrophs (Mohanty et al., 2006). In contrast, organic fertilizer addition can increase methanotroph abundance and associated rates of methane oxidation (Seghers et al., 2005)."
Here is the evidence that leads me to believe that this really is nuanced enough and the emergent properties of the system large enough to completely offset the CH4 produced when managed properly.
"Under field conditions, heavy autumnal rain in 1998 led to a dramatic increase of soil CH4 concentrations upto 51 microliters l-1 at a depth of 5 cm. Nevertheless, no CH4 was released when soil surface CH4 fluxes were measured simultaneously. The results thus demonstrate the high CH4 oxidation potential of the thin aerobic topsoil horizon in a non-aquatic ecosystem."
And here is the evidence that the whole grassland ecosystem including the animals and the atmosphere can be included in my claim:
IMPACT OF METHANOTROPH ECOLOGY ON UPLAND METHANE
BIOGEOCHEMISTRY IN GRASSLAND SOILS"At a global scale, soil uptake is the most important biological sink of atmospheric methane, offsetting emissions by about 30 Tg y-1 (Denman et al. 2007). Without this sink, Ojima et al. (1993) estimated that atmospheric methane through the 1990‘s would have increased at 1.5x its observed rate."
and
Cenozoic Expansion of Grasslands and Climatic Cooling
"Grasslands and their soils can be considered sinks for atmospheric CO2, CH4, and water vapor, and their Cenozoic evolution a contribution to long-term global climatic cooling."
So rather than blame the animals for the increase in atmospheric methane, rather blame Haber process nitrogen, something that is not needed in a properly managed pasture. From the systems science POV, when you remove the animal from the pasture and put them in a confinement system, you break part of the methane cycle, causing a nuanced chain of interactions with soil biota, quantifiably decreasing ecosystem function. Net result? You turn a net methane sink into a net methane emissions source. So it is very important to be very precise when discussing "intensive" agriculture. Managed Intensive Rotational Grazing is an intensive agriculture, but is very different than intensive agriculture reliant on expensive AGW causing inputs. Properly done, MIRG can actually help mitigate AGW, not cause it.
I believe it was foolonthehill that mentioned drought. Turns out that holistic planned grazing can also have a substantial positive influence on water content of the soil as well, making the system more resistent to drought. Here is that evidence:
Effect of grazing on soil-water content in semiarid rangelands of southeast Idaho
Of course at least in the USA, there is well managed, poorly managed, and non managed land. So even though 95%+ of all animal husbandry in the USA is the CAFO business model which I consider to be poor management, here is the evidence that leads me to believe all the land taken together is a net sink and thus refutes the myth that 'animal agriculture and eating meat are the biggest causes of global warming.'
"Agriculture (9% of 2013 greenhouse gas emissions) - Greenhouse gas emissions from agriculture come from livestock such as cows, agricultural soils, and rice production.
Land Use and Forestry (offset of 13% of 2013 greenhouse gas emissions) - Land areas can act as a sink (absorbing CO2 from the atmosphere) or a source of greenhouse gas emissions. In the United States, since 1990, managed forests and other lands have absorbed more CO2 from the atmosphere than they emit." [1]Finally you asked me about what is considered the active fraction and stable fraction of carbon in the soil. I am using the Soil Food Web model taught by the USDA-NRCS. There are other models like the Century model. Either way the stable or long term cycle carbon is called humus which lasts from hundreds on into geological time measured in millenia, as long as the soil is not disturbed.
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MA Rodger at 20:40 PM on 8 December 2015Scientists' open letter to the Wall Street Journal re: Ridley and Peiser
Charlie A @47.
You respond to TonyW@46 who was accusing "contrarians" generally of happliy "lying about the facts and, of course, cherry picking" as though your comment @42 were the target. This does raise the question as to whether you feel you are here to discuss/argue the science or simply here to argue the contrary position. Do be aware that the latter can very quickly lead to the insincere argument described by TonyW.
Further in #47 you suggest there was "erroneous conversion from emissions to forcing" within the FAR scnarios. Could you expand on that comment? I would add that I recall the FAR scenarios did begin life by being roughly specified in terms of level of forcings by certain dates so the process of their creation could be considered strange. But "erroneous"?
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chriskoz at 20:22 PM on 8 December 20152015 SkS Weekly Digest #49
To further emphasize Tom's point, COP21 will not, does not even intent to solve climate change problem. A modest or medium emision reductions they are going to agree on, is just a start albeit very important one. We know the comprehensive solution, in the implied 200ky timeframe, or even shorter 100y timeframe, is zero or even negative emissions. Future COPs will have plenty of opportunities for more effective solutions.
At the moment, it looks like a long term process, regardeless of COP21 outcome: future generations will have to deal with total emission control. On a long/implied timescale, any sustained positive emissions even 5-10% of current level may still be too fast to stabilise the climate. The level of natural emissions of "old" geospheric carbon by volcanoes is just 1% of current antropo.
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foolonthehill at 15:42 PM on 8 December 2015How much does animal agriculture and eating meat contribute to global warming?
@michael sweet
Jumping in for no other reason than that I can...
I think you will need to narrow down quite a few variables before any quantitative decision could be made. The first would be 'small flock' - your piece of string may be of a different length to mine :-)
What forage is in the paddock? how old are the animals? are you rearing them for milk or meat? will your climate necessitate supplementary feeding in winter? do you intend to use fossil fuel derived fertilisers? Even the breed of animal is another complication to be factored in.
Any reliable calculation will be a very personal one.
It's likely that there will be a tertiary agricultural institute somewhere in your country that will be able to give you information that is better tailored to your situation.
You could take a different route with non-ruminants and get some pigs/chickens... Maybe bacon and eggs can salve a possible guilty conscience?
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