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Comments 26601 to 26650:
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Jim Eager at 00:50 AM on 4 December 2015How much does animal agriculture and eating meat contribute to global warming?
Reason_4: "I am still mystified why fugitive CH4 from fossil fuel extraction or transport seems to be treated in the same way that CH4 from ruminant livestock is treated or accounted for."
Simply because the atmosphere does not care where the CH4 comes from, the additional forcing is the same regardless. -
Jim Eager at 00:46 AM on 4 December 2015How much does animal agriculture and eating meat contribute to global warming?
Saileshrao, sorry, but simply asserting that livestock respiration is anthropogenic does not make it so. It is still atmospheric CO2 in, atmospheric CO2 out. Overgrazing degradation of range land and desertification are serious but separate issues.
saileshrao: "biomass of livestock megafauna today is 5.5 times the biomass of ALL megafauna from prehistoric times!"
Citation please. The pre-European population of North American bison alone was in the order of 20-30 million.
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bjb11213 at 00:19 AM on 4 December 2015Uncertainty is Exxon's friend, but it's not ours
In most legislations, ignorance is no defence.
I wonder if there is a case in US or world courts for suing Exxon for their share of the climate damage done since 1980, when they became aware of the consequence of their actions. I say this with some reluctance as I'm well aware that the primary beneficiary of any action would be lawyers hired by both sides of the argument.
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Tom Curtis at 00:18 AM on 4 December 2015How much does animal agriculture and eating meat contribute to global warming?
CBDunkerson @44, an excellent summary. It is, however, a little over pessimistic. Research is being undertaken into how to reduce methane from enteric fermentation and from rice cultivation. Further, given that amospheric methane concentrations must be near the equilibrium value for current emissions (else the plateau of concentration over the 1990s would not have occured) such measure may feasibly limit future growth in CH4 concentration - although it is dubious, in the face of the need to feed a more than doubling of the human population, that they will permit a decease in concentration. Of greater concern in that regard is NO2, whose longer residence time means it is nowhere near equilibrium, and where reduction of agricultural emissions is more limited in potential scope.
The point remains, however, that the key task in to reduce CO2 emissions. That is not only because it is CO2 emissions alone that will cook us long term, but also because tackling CO2 emissions is likely to lead to the technology to generate slightly negative net emissions of CO2 as a compensation of whatever persistent forcing from CH4 and NO2 exists.
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knaugle at 23:19 PM on 3 December 2015Uncertainty is Exxon's friend, but it's not ours
@One Planet Only Forever
Another way to explain your point would be to consider dam construction. In my area, state law requires dams to be able to withstand a 100 year flood. That would be something like what Hurrican Camille did to Virginia back in the 1960s. However, if climate change makes the 100 year flood more like whatis now a 1000 year flood, then everything we build is rather underdesigned. Even in this case, there well always be someone who thinks a 50 year flood is plenty.
It is not that there is uncertainty in climate, weather changes one year to the next, but that climate change itself quantitatively changes the uncertainty in weather parameters that must be assumed in the design process. It may well be that today's robust design in 50 years is woefully inadequate.
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CBDunkerson at 22:48 PM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
I think we have established that the long term impact of livestock methane emissions is likely to be very low (when we consider that it will decay to CO2), zero (when we consider that the emitted carbon is essentially re-cycled from the atmosphere to begin with), or even negative (when we consider carbon sequestration from waste).
Given this plausible range of 'very little harm' through 'some benefit' it seems clear that we can pretty much ignore the issue. Long term, methane from livestock isn't going to be a problem. The same can probably be said, for similar reasons, of methane from rice production and even landfills. Methane from fossil fuels doesn't have the 'recycling' and 'sequestration' conditions, but it still decays to CO2 and thus will have a small long term impact... especially as it will inherently decline if/when we get the much larger direct CO2 emissions from fossil fuels under control.
Ergo, I would argue that we can all but ignore methane for long term planning purposes. We need only look at its 'short term' (e.g. through 2100) impact. Unfortunately, given Tom's analysis and IPCC flow diagram, there I do see a problem. So long as the human population continues to grow I see very little chance of preventing methane emissions from livestock, rice, and landfills from also growing in response. That will mean continually increasing emissions and atmospheric levels. In one sense, these human activities which temporarily convert some of the CO2 to methane are one of the 'sinks' slowing the growth of atmospheric CO2 levels... which unfortunately results in a net warming increase. That means, short of radical changes to the global food supply and/or waste handling, the 'short term' warming from methane will continue to grow so long as the global population does.
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Dikran Marsupial at 22:17 PM on 3 December 2015Murry Salby's Correlation Conundrum
BTW from figure 1, you can see that the net natural sink has been growing over time, which suggests that the net natural sink is a response to increasing anthropogenic emissions. If you extrapolate backwards I suggest you will find that the net natural sink would hit zero sometime in the 19th century. In reality a small net natural sink has been in existence for rather longer, but the rate of increase isn't exactly linear, so the extrapolation doesn't give a precise estimate.
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Dikran Marsupial at 22:08 PM on 3 December 2015Murry Salby's Correlation Conundrum
"If the earth system is a net sink for CO2, and if human contribution prior to the industrial revolution was insignifigant, then shouldnt the long term trend of atmospheric CO2 prior to that point in time be headed towards zero ? "
No, the carbon cycle has feedback mechansims that tend to increase the amount of CO2 in the atmosphere and others that tend to decrease it. So if you leave the carbon cycle to its own devices, it eventually finds an equilibrium atmospheric concentration and stays fairly constant (which is what we observe in the ice core records, during interglacials, the level returns to more or less the same level each time). However, if you do something to upset the balance (e.g. fossil fuel emissions), then the various feedback mechanisms tend to act to try and return the atmospheric levels back to normal (this is apparently known as LeChatellier's principle). The reason natural emissions and uptake are out of balance is because anthropogenic emissions have perturbed the previously stable equilibrium. In pre-industrial times, natural emissions and natural uptake were approximately balanced, and so atmospheric CO2 levels were relatively stable.
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Reason_4 at 22:01 PM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp and Jim Eager @ 34 and 35
I'm well aware of the difference in warming/forcing potential between CO2 and CH4.
I am still mystified why fugitive CH4 from fossil fuel extraction or transport seems to be treated in the same way that CH$ from ruminant livestock is treated or accounted for.
Yes, both have the same forcing potential, but one is at least carbon (not forcing) neutral while the other ... isn't.
Let me try another way. We have yet to raise ruminant animals on our mini farm, but more from lack of knowledge and unwillingness to be tied to the property 365 days a year than for any environmental concern. But it is in the long term plan.
When we do I want to be well armed to defend our choice against those that say we are destroying the planet by keeping cattle or sheep. I will hopefully convince someone from the local Uni to take some before and after soil samples to demonstrate the increased carbon sequestration nutrients from large animal manure helps create. If we can point to greater carbon sequestration than is likley to be emitted, and there is no need for externally sourced feed or fertilisers, we would be justified in stating the meat we produce is carbon negative ... right?
If we can justifiably make that claim ... again, just why is fossil fuel sourced methane treated exactly the same as livestock sourced - because if that is all that is counted, our carbon negative cattle ... are anything but. Right?
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Dikran Marsupial at 21:53 PM on 3 December 2015Murry Salby finds CO2 rise is natural
The first factual error he makes is at 1:15 and is the first piece of scientific information given in the talk. He says:
"The IPCC position is exclusive; the increasing CO2 results from anthropogenic emissions entirely"
This isn't actually true, in AR5 says (page 493)
"With a very high confidence, the increase in CO2 emissions from fossil fuel burning and those arising from land use change are the dominant cause of the observed increase in atmospheric CO2 concentration"
The reasons they say "only "dominant" is because there are also emissions from cement production, but also to allow for the possibility of some component due to ENSO (I know this because I asked for clarification). So Salby misrepresents the IPCC in the very first statement. Not a good start.
The fact that the natural environment is a net carbon sink is, somewhat ironically, established by the equations he gives on the slide from 5:12. If instead of plugging in the IPCC estimates for natural fluxes, you use the observed growth rate to infer the difference between natural emissions and natural uptake, you find that natural uptake is always greater than natural emissions. This directly refutes Prof. Salby's conclusions, and he has been informed of this, but he contines to ignore that and doesn't mention in in his talks. You can find an explanation of why in my article on an earlier talk (I sent him a copy for comment before publishing it, but recevied no reply).
My article also explains his mathermatical error that starts with the following slide (note he never states exactly how he gets the data for that graph, and ignored my request for clarification).
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saileshrao at 20:08 PM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
Jim Eager @ 35,
Livestock is NOT in equilibrium with the environment as the accelerating desertification of grasslands and pasture lands clearly shows. Indeed, the biomass of livestock megafauna today is 5.5 times the biomass of ALL megafauna from prehistoric times! Therefore, the breathing contribution of livestock is an anthropogenic contribution to the imbalance in the Earth's carbon cycle.
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saileshrao at 20:00 PM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
Tom Curtis @28, HK @ 33,
Pierrehumbert's argument is that methane concentrations in the atmosphere will decay exponentially with a short half-life of 12.4 years. That is clearly not the case in reality as we continue to pump fresh methane into the atmosphere year after year, while pretending that methane is benign compared to CO2.
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RedBaron at 19:53 PM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp #39
That is an excellent point. Sometimes people, even great scientists, get so wrapped up in the minutia of detail, they overlook the the bigger picture. The same thing that can be asked about rice paddys can be asked about meat production. How is it that the grassland/grazer biome responcible for long term global cooling on the planet, is now contributing to warming? (see post #21) What has changed since the industrial era? If you approach the problem from that perspective, I think the science is where the change in production methods might change the fundamental balance in the carbon cycle. That's where your interesting research can be found. What are the differences between a grassland/grazer biome and a cropland biome where the animals have been removed and instead raised in CAFOs? Rather than blame the animals themselves for AGW, I personally think the only conclusion anyone can make is the production methods have changed.
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bozzza at 16:05 PM on 3 December 2015Uncertainty is Exxon's friend, but it's not ours
@4, uncertainties change. The problem is no one can put their finger on any solid numbers with enough certainty to warrant investor panic.
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bozzza at 16:00 PM on 3 December 2015Uncertainty is Exxon's friend, but it's not ours
@1 the point you raise is, I suspect, even more poignantly significant, if not terribly ironic, than you first thought.
Ignorance of the law is no excuse: but of the moral law apparently not so!
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scaddenp at 12:12 PM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
What matter with paddy production though is how much is it changing? Absolute emissions arent as interesting as how much change has occurred in 20-21 century.
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Digby Scorgie at 11:01 AM on 3 December 2015The Road to Two Degrees, Part Two: Are the experts being candid about our chances?
Tom Curtis, I think your final paragraph is the one that's really relevant. It relates to the very first graph in the above article, from which we see that we only have about two decades in which to make drastic reductions in fossil-fuel use. And there are some parts of the fossil-fuel system that are built to last quite a bit longer than two decades — ships, aircraft and coal-fired power stations are some that come to mind.
Anyway, Tom, I don't know about you, but I find myself in the position of someone having an interesting philosophical discussion on the deck of the Titanic — after the ship has hit the iceberg. But then, being an old man, I can afford to take a dispassionate view of the whole catastrophe.
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Mal Adapted at 10:47 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
Thanks to scaddenp for the reference to table 6.8 (not 5.8, sorry), on page 507 of the AR5 WG1 report. It shows that in the interval 2000-2009, rice cultivation contributed 36 Tg/year to the total 331 Tg/year of anthropogenic methane emissions, compared with 89 Tg/year for ruminants. I'm not surprised that vegans aren't calling for an end to rice production, however.
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scaddenp at 10:22 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
RedBaron, i am in no way claiming that ruminants are only source of biological methane. I am really claiming that if you increase the number of ruminants (in particular since pre-industrial benchmark), then you are getting more methane into the atmosphere than if you had left them at preindustrial level. Increase in methane from any source is a concern, but the to-date, increase in ruminants is a major source. Numerous papers on this cited in IPCC report and working groups on methane. A review paper here could be starting point. Other sources of anthropogenic methane including paddy agriculture, landfills, manmade lakes/wetlands and waste treatment are considered in CH4 inventories. Table 5.8 in IPCC AR5 WG1 report lists source of methane with references. (Ruminants contributing 89 Tg/year of the total anthropogenic source of 331). The same table also lists natural sources but for consideration of change in methane level (and hence warming), it the change from pre-industrial at matters.
Note also that 2/3 of methane production from cattle is enteric rather than from manure.
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RedBaron at 09:48 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
@scaddenp #34
Please supply some citation showing that this statement "there is more GHG effect than you would have if you had no animals (or no ruminants)." has been properly analysed and is true. Methanogens are microorganisms that produce methane as a metabolic byproduct in anoxic conditions. That certainly is true. But they are certainly not unique to ruminants. In fact methogen archaea are ubiquitous in the environment and soils. In some areas for example termites far exceed the methane production of any ruminants. Nor are methogen archaea the only source of methane produced by decomposition and incomplete oxidation of the products of photosynthesis. Nor is methane oxidation in the atmosphere the only way to reduce methane to CO2 as methanotroph prokaryotes are also ubiquitous in many environments. I have yet to see any documentation of any analysis of methane production that proves ruminants increase atmospheric methane over other forms of decomposition or incomplete oxidation of organic material except in the artificial feedlot/cess pool production model. And even then the methane can be collected and used as a biofuel.
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Jim Eager at 08:52 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
Reason_4, CO2 from respiration is not counted because it is 100% carbon neutral: the C respired into CO2 came from the plant matter eaten by the livestock, which came from CO2 in the atmosphere. There is no new CO2 and thus no additional forcing.
The methane emitted by ruminants also came from the same source (atmosphere CO2 > C in plants), but it is counted because it is emitted as CH4 rather than as CO2, which produces a greater forcing than the original CO2 until it is oxidized into CO2.
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Riduna at 07:40 AM on 3 December 2015G R A P H E N E
MA Rodger @ 18 suggests that graphene technology has yet to leave the lab. However, graphene technology is leaving the lab and being commercialized. Evidence of this is provided by the decision of Grapheno to produce batteries using graphene polymer in electrodes at a new 7,000 m2 factory in Spain(1). The batteries are reported to be ~5 times more efficient than existing batteries.
(1) http://www.graphene-info.com/graphenano-announces-launch-manufacturing-plant-graphene-based-batteries
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scaddenp at 07:07 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
Reason_4. Carbon is cycling all the time. Plants absorbs it CO2, plant decays and returns CO2 to atmosphere. Animals/humans eating plant and emitting CO2 is slight variation from this schedule. Breathing by any animal is carbon neutral -none of this changes net CO2 in atmosphere (unlike releasing fossil carbon). Ruminants are slightly different. A portion of plant carbon is released as CH4 instead of CO2 and it takes time for the CH4 to be oxidized to CO2. Over the time period before oxidization, there is more GHG effect than you would have if you had no animals (or no ruminants). The calculation of greenhouse gas potential for agricultural emissions is not a trivial calculation.
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scaddenp at 06:50 AM on 3 December 2015Models are unreliable
Model predictions for a parameters with a huge amount of unpredictable internal variability like surface temperature do take time to validate. However, the models predict a great many other variables with far less internal variability (eg OHC, clear sky surface radiation etc) and can be tested on that. Have you read the IPCC chapter on model validation?
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How much does animal agriculture and eating meat contribute to global warming?
Saileshrao #26:
"....where methane concentrations in the atmosphere have been monotonically increasing year after year."Really?
Not between 1999 and 2007, and much less after 2007 than before 1992!
Also note that the forcing growth rates from GHG’s other than CO2 decreased rapidly in the 1990’s.
So, when it comes to methane, I’m more worried about emissions from thawing permafrost and other possible feedbacks than directly from human activity that we can control.
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Tom Curtis at 06:02 AM on 3 December 2015There's no empirical evidence
blue65 @304:
1) The incoming radiation is for the most part, Short Wave radiation to which CO2 is transparent. Hence there is not significant redirection of "... energy by the increased CO2 before it reaches the lower atmosphere". It is the contrast between transparency to incoming radiation, and relative opaqueness to outgoing radiation that it is the key feature of greenhouse gases, and which makes them greenhouse gases.
2) Changes in the landscape are a factor, and are itemized by the IPCC as Land Use Changes (LUC). Overwhelmingly the effect of LUC is to reflect more solar radiation back out to space (increase albedo), thereby cooling the planet. However, the effect is small relative to the effect of changing concentrations of greenhouse gases and aerosols. The effect is itemized on the chart below as "Albedo change due to land use":
3) The temperature effects of cities relative to countrysides are a combination of changes in albedo but that is variable (concrete has reduced albedo but ashpalt has increased albedo); changes in thermal inertia, with most modern construction materials having low thermal inertias relative to plant matter (probably due to limited water content); and a large number of sources of industrial waste heat in cities (the "urban heat island effect"). Changes in albedo from cities also result from increased aerosol production which also effects countryside downwind from cities (an effect that has been detected). The net effect can be to warm or to cool cities relative to the local countryside. The total globally averaged effect is small relative to the forcing from greenhouse gases.
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John JMesserly at 05:53 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
TomR was spot on about the weight mistake the EWG chart makes. Consider the FAO report "Tackling Climate Change through Livestock" (2013), page 16, figure 3 where you will find a chart graphing against protein content. What may surprise some vegetarians is that Milk is hardly one of the lowest as indicated in the EWG graph, but actually is higher in CO2e per kg of protein than some meats like pork or chicken. This is due to the previously discussed massive amount of methane produced by ruminants- a byproduct of cellulose breakdown by methanogen microbes in their guts.
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Reason_4 at 05:44 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
Dana @29
I appreciate that, although as a permaculturalist I also understand the reverse is also possible (you can take already degraded land and dramatically improve carbon sequestration in a system that may well integrate raising animals to further enhance this aspect).
But I'm still curious about the first point - why some animal emissions are tallied (eg methane from ruminant animals) and others not (CO2 respiration from any animal) and then listed as equivalent to the same emissions from fossil fuels (either burnt or fugitive) when one is effectively carbon neutral in the short term carbon cycle ... and the other definitely isn't.
We (of course) dismiss deniers who suggest humans need to stop breathing/belching/farting ... why are some livestock emissions treated differently?
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Models are unreliable
reuns - You open your comment with an incorrect statement: "the best model is a will stay for a long time the linear interpolation of past observations". This is completely wrong when looking at non-linear forcings applied to (in this case) climate. If the behavior is non-linear, a linear projection will be wrong.
'Signal processing', or more appropriately statistics, is fine for analyzing past behaviors of a system. But projecting ahead in a SP approach requires (gasp) actual physics, and looking at the input/output relationships involved.
The rest of your comment is essentially a claim that the climate is too complex to model and project, which I believe has been sufficiently addressed by the fact that observed temperatures and for that matter regional patterns are indeed reproduced within expected variation by GCMs.
It's physics all the way down - if modeling does a reasonable job of reproducing the physics, we don't need to test an infinite variety of cases. That's just a call for delay, which turns into a continually moving goalpost fallacy where there will never be enough information (in the opinion of the delayers) to make any kind of decisions...
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blue65 at 05:33 AM on 3 December 2015There's no empirical evidence
The problem I see with this theory is that it seems to discount the effect of redirected energy by the increased CO2 before it reaches the lower atmosphere. Insulation works both ways. Put a dark background behind a 2 way mirror and almost light is reflected: put a light source behind it and it becomes see through. Changes to landscape are as much a factor as any in my belief. My imperical evidence is easier to prove; just check out the daily high and low temperatures of any metropolitan area and the rural areas next to them and see the contrast.
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Tom Dayton at 05:14 AM on 3 December 2015Satellites show no warming in the troposphere
Eli has a great post on UAH's flaws, by a satellite engineer who gives lots of details: UAH TLT Series Not Trustworthy.
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foolonthehill at 04:41 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
RedBaron @27 - Re: Savory - plausability is nice but reproducability is better.
'Holistic management does not permit replication. Because of this fact we can only validate the ‘science’ used and monitor or document ‘results achieved’. Note: This point is critical to understanding the great difficulty reductionist scientists are experiencing trying to comprehend holistic planned grazing – because no two plans are ever the same even on the same property two years running, planned grazing cannot be replicated which reductionist scientists do to try to understand the ‘science.’
If one replaces 'holistic management' with 'homeopathy' then maybe you can understand my scepticism.
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Rob Painting at 04:29 AM on 3 December 2015Satellites show no warming in the troposphere
We will know if the current super El Nino is affecting the satellite record like the super El Nino of 1997/1998 when the December & January data come in - assuming the behaviour is similar to past El Nino.
As for Kevin Cowtan's Skeptical Science calculator - note the error bars are orders of magnitude larger than the trend, so there is no statistical basis for any claim that it has cooled. The time period is too short and the interannual variation (standard deviation) too large. We would need a longer time period in order to establish statistical significance. Note that contrarians never attempt this, they simply make a claim without supporting evidence.
It would be interesting to find out why the satellite data 'overreacts' to El Nino and La Nina though. Is this a real phenomenon occurring in the lower troposphere? Or is this an artefact which all the processing fails to remove from the microwave soundings?
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dana1981 at 01:43 AM on 3 December 2015How much does animal agriculture and eating meat contribute to global warming?
Reason_4 @ 23 - you have to consider what the land would be used for if it weren't being used for livestock pasture land. For example, when forest land is replaced by pasture land, that's actually a decrease in natural carbon sequestration.
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One Planet Only Forever at 01:11 AM on 3 December 2015Uncertainty is Exxon's friend, but it's not ours
ryland@4
Thinking a little more about your question the following may be the answer you were asking about.
The typical design basis for structures and water run-off is not the range or variation of weather conditions for a location, it is the statistical expected extreme of a design condition such as the maximum large-field wind speed expected to occur once in a 50 year period. My use of the term large-field is meant to differentiate the wind speed experienced concurrently by all of a large structure vs. the faster wind speed and resulting larger local forces a structure.
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knaugle at 01:09 AM on 3 December 2015Satellites show no warming in the troposphere
I agree with the RSS showing long term warming. However, the claim from the "skeptics" is no warming since 1998. If you throw out 1998 and look at the past 15 years, 2000.9 to present (that "escallator thing", RSS and now UAH 6.0 show cooling). So long as that is the case, politicians like Lamar Smith will simply claim NOAA is fudging the numbers. I do find it curious that UAH has adjusted its data about as often as any other entity out there with a temperature data set while RSS seems rather mum on versioning. Yet whenever NOAA adjusts its data set, it's called "fraud".
Note also that back in 2013, RSS was very unapologetic in declaring that most all the climate models are "wrong" and their graphs claim the breakout occurred around 2000, not 1998.
http://www.remss.com/research/climate
Finally from Dr. Cowtan's temperature plotter, the warming from the satellites is
0.122 C/decade since 1979 as was shown,
but 20 year and 15 year trends show
0.037 C/decade since Dec. 1995 and
-0.017 C/decade since Dec. 2000.
So interestingly while deniers bank all on the 1998 El Nino, we do need to avoid the mistake of expecting much from the current one as a fix. -
One Planet Only Forever at 00:55 AM on 3 December 2015Uncertainty is Exxon's friend, but it's not ours
ryland@4
The climate affected design values for any region are based on the past history of gathered observations and the associated related understanding of the weather effects at a location.
Rapid Climate Change and the uncertainty of how any specific location's weather extremes will be affected reduces the certainty of appropriate design values because the observation history is a less certain basis for determining appropriate design values.
So my reference to Climate Change is to the current term being applied to the more rapid climate changes now better understood to be caused by human impacts. Climate has always changed ... rather slowly.
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reuns at 00:39 AM on 3 December 2015Models are unreliable
the best model is a will stay for a long time the linear interpolation of past observations :
physical sub-models with many parameters are useful to predict events which vary importantly and are testable,
but by defintion the global warming is not : it is a very small increase of temperature (of energy) resulting from very small increase of many parameters (the 1st one being CO2 concentration),
so forget the physics and study signal processing instead !signal processing says that :
the more the model is complicated and not testable and the more the observations are random and not pure signal (signal to noise ratio), the the more the simpler model will be the best (linear interpolation)
the only way to overcome that problem is to get enough datas to model many sub-paramters which vary a lot and ARE testable :
such as a huge change in rainfall somewhere, a big and suddent change in somewhere in the ocean temperature or acidity, anything which vary a lot,
then find some physical explanations of that, test it and predict some non-trival facts (so prove your non-trivial physical explanation that was unknown or unproven before) and find some ways to extrapolate it to the global observations. do that many times with many researchers and after many time you'll be able to explain and predict and substract what was before considered as NOISE : once you explained that noise you'll get much cleaner observations and with a better signal/noise ratio and so on you'll be able to create better models.
this will take at least 20 years. -
Tom Curtis at 23:43 PM on 2 December 2015How much does animal agriculture and eating meat contribute to global warming?
saileshrao @26, in the 322 months from April 1987 to Jan 2014, using Mauna Loa data, 142 had 12 month average CH4 concentrations less than the maximum 12 month average concentration to that date (most recent: April 2013. 10 of the 27 annual averages over that period are less than the maximum to date (most recent: 2006). In short, CH4 concentrations are not increasing monotonically.
The Pierrehmbert quote again was:
"A re-examination of the issues shows that the benefits of early SLCP mitigation have been greatly exaggerated, largely because of inadequacies in the methodologies used to compare the climate effects of short-lived substances with those of CO2, which causes nearly irreversible climate change persisting millennia after emissions cease. Eventual mitigation of SLCP can make a useful contribution to climate protection, but there is little to be gained by implementing SLCP mitigation before (my emphasis) stringent carbon dioxide controls are in place and have caused annual emissions to approach zero."
Again, he is not saying that addressing Short Lived Climate Pollution is pointless, but only that it is a second order priority to reducing CO2 emissions. The reason for that is that the effects of SLCP in general, and of CH4 in particular will be negligible after 100-200 years, whereas the effects of CO2 emissions will persist for thousands and even tens of thousands of years into the future. Three hundred years from now, current CH4 emission rates will be a matter of historical interest only; whereas current CO2 emission reates will be having ongoing negative impacts. Prioritizing effects which are beneficial only over the short term ahead of effects that will persist longer than our civilization shows somewhat distorted values.
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RedBaron at 23:03 PM on 2 December 2015How much does animal agriculture and eating meat contribute to global warming?
@ lorainel #17
The issue is that you have two complex factors involved, one is the fact that feedlot beef is fed from cropland, and it does take substantial amounts of fossil fuels to run the tractors, fertilizers and insecticides made from fossil fuels, harvest the grain, dry the grain, ship the grain, turn various mixtures of grain/silage/hay into feed suitable for cows, ship the feed again. Not to mention you have to load up the beef cows and transport them live to the feedlots in the first place. There is a big difference between that and a cow simply walking over to the next fresh pasture. Feedlot production is very inefficient in terms of fossil fuel use.
Then there are unexpected emergent properties of the system as well, compared to pasture, cropland also has a much lower community of methanotrophs, and mycorrhizal fungi, both of which are responsible for sequestering large quantities of greenhouse gasses. You could look at them as carbon pumps into the soil via the grassland's symbiotic relationships. So as it turns out, cows raised on properly managed pasture end up being part of a larger net carbon sink, not a net carbon emissions source, while cows raised in feedlots are an even larger emissions source than commonly known when you include the cropland supplying the feedlot.
Nevertheless, even as bad as feedlots can be, they are not as bad as the exaggerated claims by certain Vegan propaganda sites, which have exaggerated their impact on AGW, to take advantage of the new "sexy" environmental awareness campaigns on global warming mitigation. They basically do this by first cherry picking the harmful parts, ignoring anything that doesn't promote their dogma like the 1/2 life of methane in the atmosphere, and then double counting things like transportation, cropland emissions etc. Finally the fallaciously claim that eliminating meat consumption is the solution, rather than changing the management and production methods.
You also proclaimed your skepticism of Savory, the leading scientist in the field of rangeland management. OK skepticism is fine, I am a skeptic myself. However, to be a really good skeptic requires study. This may help.
I think the more you study it, the more plausible Savory's work becomes, athough in the beginning, most people find it counterintuitive. Real hard to argue with the results though. For your personal ranch, I wouldn't worry too much about the impact to AGW. You have a grassfed production model, so more likely than not you are mitigating AGW rather than causing it, assuming you are properly managing it for that purpose. Keep in mind undergrazing can be just as bad as overgrazing in certain climatic conditions. But as long as your management plan includes proactive monitoring, you'll be able to figure that out soon enough.
Moderator Response:[RH] Shortened link that was breaking page format.
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saileshrao at 21:11 PM on 2 December 2015How much does animal agriculture and eating meat contribute to global warming?
Tom Curtis @20:
Pierrehumbert's assumption clearly does not match reality where methane concentrations in the atmosphere have been monotonically increasing year after year. -
ryland at 20:04 PM on 2 December 2015Uncertainty is Exxon's friend, but it's not ours
One Planet Only Forever @3
Not sure why you head your list of uncertainties to be considered as "The climate change uncertainties include:". Surely these uncertainties have always applied to the climate rather than to climate change. Are you saying these uncertainties are only now being considered?
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Rob Painting at 19:25 PM on 2 December 2015Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
"A large amount of effort goes into "proving" a causation using correlation, multiple regression, etc., but consider that when the rooster crows, the sun comes up, but that certainly does not mean that he rooster causes the sun to rise."
Yes, I am certain that none of the authors have suggested that evaporation in either the Red or Mediterranean Sea caused global sea level to fall.
Your comments don't make a great deal of sense. How could the ocean basins shallow and deepen in concert with Milankovitch forcing? And where did the water locked up as ice in the vast Laurentide and Fennoscandian ice sheets disappear to if not into the ocean?Moderator Response:[PS] Dr T comments suggest that he/she hasnt actually read the Grant (2012) paper.
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OnceJolly at 16:36 PM on 2 December 2015How much does animal agriculture and eating meat contribute to global warming?
lorainel @18 - Stephen Walsh provided a useful critique immediately after the Goodland and Anhang analysis was released. I've filled in some additional details here, though the criticism is essentailly the same as Walsh's.
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Maaark at 15:54 PM on 2 December 2015Heat from the Earth’s interior does not control climate
Thanks
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Tom Curtis at 15:10 PM on 2 December 2015How much does animal agriculture and eating meat contribute to global warming?
chriskoz @22, a very good point, and one I should have picked up @20.
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Reason_4 at 14:58 PM on 2 December 2015How much does animal agriculture and eating meat contribute to global warming?
Thanks very much for this much needed rebuttal Dana, but (yes sorry, always a 'but'!) for the scientifically challenged can you;
(a) explain why carbon in the short term carbon cycle is not treated differently or (apparently) offset against carbon sinks in the pasture, soils and feed crops within the animal raising agricultural systems? Wouldn't the distinction between fossil fuel sourced emissions be much greater if it was?
and
(b) one would expect that the American emissions would be close to worst case (being heavily dependant of industrial feedlot production. When defending oneself against rabid vegans of the 'you can't eat meat if you want to save the world' school - are there examples in the literature about best case, grass fed meat production?
Maybe it is just wishful thinking, but isn't this at least feasibly a carbon negative pursuit especially when carbon sequestration in healthier soils is taken into account?
TIA
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One Planet Only Forever at 14:22 PM on 2 December 2015Uncertainty is Exxon's friend, but it's not ours
As a Civil Engineer, who also happens to have an MBA, I have always been very concerned about the 'uncertainty' related to the ability of built things to survive severe events (it has been my life's work).
The most severe expected events are the design basis for so many things. Uncertainty of global climate change affects every existing and planned to be built structure (and rain run-off affected system) that Exxon (and every other pursuer of profit) relies on to hope to 'make money'.
The climate change uncertainties include:
- how fast the winds will blow?
- how intense can a localized gust be?
- how rapidly can a localized rain event accumulate?
- how much total rain can fall in an event (in a day or a multi-day event)?
- how much snow might accumulate including wind blown drifts?
- how wet and heavy will accumulated snow be?
- how much ice may form due to freezing rain?
- how much ice will form on a waterway - enough for a winter bridge?
- how rapidly will ice breakup on a waterway and potentially dam it, damning anyone upstream and threatening everyone downstream when the unplanned dam breaks?
- what is the highest temperature condition a structure will be exposed to?
- Will permafrost be able to be kept as permafrost?
- What is the highest water wave likely to hit a sea-side feature?
- And so much more ...
Increased uncertaintiy of the design requirements results in increased risk of failure of existing items to perform their required function. And it results in increased risk of failure of newly designed items unless extra expense is made upfront in the hopes that some degree of 'hoped to be over-design' will be enough over-design.
The truth has always been that gambling risk-takers pursuing maximum personal gain willingly gamble on getting away with cheaper, riskier and more damaging pursuits betting that they will 'not personally suffer the consequences (even if they know that other people would be likely to suffer immediate consequences but be unlikely to be able to penalize the trouble-making gambler). And those gamblers love it when the consequences are likely to be in the future rather than be immediate consequences because future people are even less likely to be able to penalize such a deliberate gambling trouble-maker. An engineer's responsibility is to protect the public from such pursuers, not to maximize profit for them.
The truth is there will always be some people who are determined to demand more freedom to do things they actually understand are less acceptable. And those people will always try and try again to get away with less acceptable pursuits of personal benefit by claiming their freedoms cannot be restricted except by absolutely certain proof, not just proof beyond a reasonable doubt, of the unacceptability of what they want to get away with.
National design and construction standards are also under arttack as international competition leads pursuers of profit to challenge why a national standard 'has to be met when they can find a lower standard somewhere else'. That pursuit combined with the denial of climate change is a double-down bet made by many wealthy gamblers who illigitimately won through their competetive advantage that was obtained by deliberately caring about others and the future as little as they can get away with.
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DrivingBy at 14:14 PM on 2 December 2015Uncertainty is Exxon's friend, but it's not ours
I find it hard to get too wound up about what a bunch of suits who are not scientists did or did not express on a scientific topic. Morally, they made a bad choice, but since they are legally obligated to persue the interests of company shareholders rather than their own, or even a moral cause, it's a bit of a mess. We (in the USA) no longer acknowledge that there exists any higher law than immediate convenience, and so a CEO of a public company who declares they are going to take a hit for the next 20 quarters because of X moral reason is likely to be fired, and could be personally sued for any lost company income.
Considering that they're required to express the interests of the shareholders, I don't understad why anyone would even ask them about climate change, much less give their answers any weight. Exxon did not have climate science locked away from the public, the science of interest was and is available to the public for anyone who cared to read it.
In short, the execs made a bad choice, but it is absurd to blame them for the failure of others to use their own minds.
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What is popularly believed to be true changes from time to time, usually due to fashion, sometimes due to passion, and within natural science and on rare occasions due to an advance of knowledge. If we get in the habit of putting people in the dock for expressing incorrect thoughts, the people in the concrete cells will be the creative ones, the scientists and those insist on pointing out that the emperor has a hairy ugly beer gut.
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Ken in Oz at 13:01 PM on 2 December 2015Uncertainty is Exxon's friend, but it's not ours
I find it dismaying that Exxon executives, like tobacco execs, will only be in formal trouble for misleading Congress or giving other kinds of false sworn testimony; the climate consequences of their decisions will probably not even be in the running as something they will be held responsible for.
More broadly I wonder if there is a clear incentive for executives to avoid being well informed because if they remain ignorant they can argue they didn't know and avoid liability arising from their decisions.
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