Livestock Climate Impact Claims Junk Science?

Dear Dr. Steinfeld,

 

In your capacity as coordinator of LEAD-FAO, you are the principal author of “Livestock’s Long Shadow.” This report’s main message (which claims that domestic animals contribute 18{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} to anthropogenic Green House Gas (GHG) emissions caused a major storm in the global media. The concern about livestock’s alleged contribution to climate change culminated with a hearing in the European Parliament on the topic “Less Meat = Less Heat.”

 

In summary, the above-mentioned report caused considerable damage to the reputation of animal husbandry in general, and in particular to the grassland based production systems. In a series of talks (almost 2 dozen), which I gave in the past 7 years in Paraguay, Argentina and other countries at national and international congresses and seminars, I strongly criticized several basic assumptions and methodological approaches in the above-mentioned report.

 

Meanwhile, however, I got the impression that the FAO had quietly abandoned its critique of domestic livestock promoting climate change, as it had become fairly quiet around this topic. Unfortunately I was mistaken: I was quite surprised when I recently discovered another report on the homepage of FAO, for which once again you are one of the principal authors, ‘Tackling Climate Change Through Livestock.’

 

In this publication, the contribution of global domestic livestock to the anthropogenic “greenhouse gas” (GHG) emissions has been somewhat reduced to “only” 14.5{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} as compared to the above mentioned previous report, however,

 

– it still contains the same methodological deficits,

– ignores the uncertainties associated with the climate sensitivity of so called

GHGs,

– and ignores the inconsistencies between some of your conclusions and

several empiric observations in the real world.

 

After 7 years of intensive scientific examination of this topic, I feel obliged to challenge you with the following 7 questions, which I ask you to answer succinctly.

 

I think the worldwide community of taxpayers, of which I form part too (in Paraguay and Germany) and which finances the FAO in order to comply with its mandate (to contribute sensibly to global food security), has the right to see the FAO rejecting well-founded doubts with its mandate compliance or, alternatively, heading to an institutional course correction.

 

It certainly cannot be the function of the FAO to discredit grazing systems in general and the beef sector in South America (the continent with the highest growth potential for food production) in particular, with unrealistically high emission values due to methodological inconsistencies and negligence and due to overstating the relevance of these emissions.

 

Being a cattle rancher in Paraguay, native of Germany, I also feel personally challenged, not to say threatened, by your journalistic activities.

 

Here are my questions:

 

1) Do you agree to the following statement? The assumption of noticeable climate sensitivity to anthropogenic GHG-emissions (as defined as the mean increase of global temperature with a doubling of CO2-equ. in the atmosphere) is the basis for the hypothesis that livestock husbandry could eventually influence the climate (cause global warming).

 

2) Do you agree that considerable doubts with noticeable climate sensitivity to “anthropogenic GHG-emissions” are justified, in the light of the following facts?

– Mean global temperatures were flat in the past 15 years, and did even slightly decrease in the past 10 years, in spite of steadily increasing CO2-levels in the atmosphere which even caused a remarkable greening of the deserts in the past 30 years by fertilizing plants and making them more drought tolerant (CSIRO 2013). This is an empiric observation contradicting all the scenarios of projected temperatures

published in the past 4 IPCC assessment reports.

 

– There is an overwhelming number of peer reviewed papers, and among them various recently published ones that acknowledge the existence of various warm periods during the Holocene (after the end of the latest ice age), which were warmer than or at least as warm as the present age (in spite of the pre-industrial atmospheric CO2-levels at those times).

 

– In the AR4-IPCC report 16 variables are identified as forcing agents of global warming / climate change and are used in the models. The level of understanding for 11 of them was specified by the IPCC as ‘very low or low’ (Table 2.11 in IPCC AR4, 2007).

 

However, models made with uncertain variables require empiric validation. As far as the modeled temperature projections for a variety of emission scenarios published by the IPCC in the past 4 assessment reports can already be tested with observed temperature data, recent temperatures are located well outside the confidence intervals of all IPCC-models, which therefore did not pass its validation exam (Fig. 1.4. of second order draft of IPCC-AR5).

 

If you negate this question please indicate why.

 

3) If you affirm questions 1 and 2, why do you not allude to the mentioned uncertainties, constraints and inconsistencies in your report “Tackling Climate ChangeF.”?

 

4) Comparing the global domestic livestock distribution and the geographical distribution of atmospheric methane concentrations (determined with the satellite ENIVSAT) there is no consistent relationship to be found between both items. The historical evolution of the mean methane concentration in the atmosphere (including the decline of the growth rate from about 1980 on) is determined by fossil fuel extraction and use, as well as the associated technological quality standards (Quirk 2010 and Aydin et al. 2011).

 

As there is no livestock signal discernible, neither in the global methane distribution nor in the historical evolution of the atmospheric methane concentration, would you agree to the following statement? ‘Domestic livestock is obviously irrelevant for the global methane budget.’

 

If you disagree, please tell me why.

 

5) The only continent you are blaming for CO2-emissions from deforestation for pasture establishment is Latin America and Caribbean. South America is charged with the very high “emission intensity” of 100 kg CO2-equ. per kg of CW (carcass weight) produced, of which 40 kg CO2-equ. per kg CW is attributed to deforestation.

 

This is justified with the ascertainment that in other continents there have been no significant deforestations for pastureland expansion recently. However, in other continents, particularly Europe, extensive deforestations took place already centuries ago to establish permanent grasslands.

 

Mathematically the term “emission intensity” (used in your report) describes the emission of a certain quantity of CO2-equivalent necessary for producing one kg of a product (in this case carcass) under certain conditions (I prefer the term “specific emission”). It is questionable to charge this mathematical term with emissions which are not related to the generation of this particular product. For example while deforesting a specific area of land, the beef production is carried out on other pasturelands, already established earlier. In other words, the emission due to deforestation at one specific site has no immediate relationship to the ongoing production on already established grasslands.

 

It is therefore methodologically illegitimate, to allot the one-time CO2-emission from deforestation to any accidentally chosen quantity of a product (e.g. yearly beef production in South America). The single emission from deforestation is generated (and tolerated) in order to produce beef on the new pastureland to be established for a very long period of time in the future (hundreds of years just like on European grasslands). But when the single “carbon debt” from deforestation is spread over the accumulated production from the deforested area over centuries, the specific emission per kg of product tends towards

zero.

 

And in case a certain grazing area is eventually abandoned, the carbon captured by encroaching secondary forests will offset the CO2 released at the initial deforestation. Therefore other continents such as Europe are treated correctly in your report, by disregarding emissions from “Land Use Change LUC.” On the other hand, beef products from South America, are charged with far too high values of “emission intensities” (kg CO2-equ. per kg CW), because of deforestation still being practiced which has, however, nothing to do with the current beef production within the continent (in the year of deforestation) but with future production on the cleared land.

 

With your term “emission intensity” you might want to quantify the emissions actually brought about by the total beef industry sector in a specific year within particular regions, continents or production systems. However, this approach is misleading when this number is referred to a certain quantity of product (e.g. kg of CW) without advising explicitly that the above-mentioned term contains casual emissions (from recent deforestations) which arose in the respective continent but did not contribute to the product generated in that particular year but will contribute instead to the products generated in future. According to your methodological approach, 500 years ago, when there was still ongoing deforestation, Europe once reached similar emission intensities as South America today, and in 10 or 20 years’ time, when deforestation has come to a halt due to legal, environmental policy or physical limitations, emission intensities in South America will be similar to the ones in Europe today. But you do not tell readers this.

 

Without an explicit footnote explaining this context, your approach is scientifically dubious. In the tables and figures you are comparing values which are not comparable, because they need to be interpreted distinctly and some have (restricted) validity just for the moment. In that way you load (purposely?) unrealistically high emission values onto the South American beef industry and onto cattle grazing systems in general. It is not sufficient to offer values without the burden of emissions from deforestation, hidden in the text body, and to casually mention in a very general manner that the correct treatment of deforestation in the calculations is a very complex matter.

 

Moreover, the fact that you are using the period from 1990 to 2006 to quantify deforestation, while thereafter deforestation dropped considerably in Brazil (Box 5, p. 95), can be interpreted as a deliberate

discrimination of the beef production in South America by charging it with emission burdens which were already much lower at the time of the publication of your report.

 

May I make an additional observation? We could show that in the semiarid Chaco, deforestation for pasture establishment diversifies the habitats and therefore promotes species richness, provided the legal land use-restrictions of preserving almost 50{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of each farm´s surface in pristine condition (in form of a nature reserve, bush corridors and islands) are respected, as do >90{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of the land owners. The additionally created habitats and resources are extensively used by wildlife too.

 

These refer to the bush border effects over many kilometers, savannah like landscapes, nutritious pastures and rain water collection reservoirs. Pease find attached a photo my son took at a distance of 200 m from our farm house about a week ago.

 

My question: Can you follow this logic, do you share it, and if not, why?

 

6) The concealment of any baseline scenario over space and time most likely is the biggest fault of your latest publication. You interpret the direct and indirect emissions of methane and nitrous oxide by livestock at a 100{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} level as an additional anthropogenic emission of “GHGs” from animal sources. This is not the case, e.g. areas formerly populated by large herds of wildlife or areas comprising wetlands, drained later on, could emit less methane after a land use change towards pastoral and for livestock grazing than did the pristine ecosystem.

 

In other words, livestock born “GHG-emissions” need to be corrected by the emissions which would occur

anyway in a (natural or pre-climate-change) baseline scenario. This is particularly important for nitrous oxide. Grazing animals indeed somewhat accelerate nitrogen cycling; however, they do not increase the amount of nitrogen in circulation.

 

Both, the nitrogen quantity in circulation and the mean nitrogen turnover rate determine the nitrification and de-nitrification rates (besides, of course, the prevailing site characteristics such as waterlogging or temperature), which are crucial for the quantity of nitrous oxide produced as a by-product. Therefore nitrous oxide emitted from manure is by no means additionally released by livestock.

 

Herbage and other plant biomass also produce considerable amounts of nitrous oxide (N is mineralized, nitrified and de-nitrified) even without passage through livestock’s intestines. It could

well be, that N2O emissions from native forests (with often high N-contents in the leaves) are even greater than from managed grasslands. In this case the 23 kg of CO2-equ. per kg CW (from N2O) charged to the beef industry in South America, should be reduced to zero or even adopt a negative value, when the grassland is situated at a formerly forested area.

 

In any case, this number has to be corrected by the amount of N2O, which would be released by the biomass anyway, even if it hadn’t passed through the animal stomach. Only a nitrogen fertilization (which is rarely done on grazing land because of economic constraints) considerably increases the amount of nitrogen in circulation and thereby the chance of N2O emissions. This applies, however, to a far higher degree to (forage) cropping than to true pastoral systems.

 

Just like CO2, methane and nitrous oxide are also part of natural cycles. Rather than considering the actual emissions one ought to take into account the observed or theoretical difference of the atmospheric steady state equilibrium concentrations (between sources and sinks) before and after the creation of a new or additional sources of emission. If at all, only this difference of concentration of a “GHG” could exert any influence on the climate.

 

The missing data base or the high complexity of the matter (also due to the overlapping of various emission sources and sinks) doesn’t excuse you from clearly displaying this complexity rather than omitting important baseline scenarios. It would rather be correct to desist from estimating specific emission values (or emission intensities, as you call them) than to suppress weighty baseline scenarios, because they are complex and difficult to quantify.

 

Moreover, certain pastoral ecosystems may represent a sink and not a source for methane (Mark Adams, University of Sydney). This is another empirical observation which considerably reduces the utility of your

simplified bottom up calculations.

 

What do you think about this critique? Did you simply forget the baseline scenarios just like (almost?) all the authors of publications on “life cycle assessments?”

 

7) In your report you reckon that methane emissions by ruminants damage production as they constitute a waste of nutritional energy. Of course, methane emissions deliver energy to the environment, but do not spoil it, as methane is a (so far) unavoidable by-product of anaerobic degradation (by rumen cellulolytic bacteria) of the most widely spread substance in the biosphere, cellulose.

 

Without methanogenesis, hydrogen (H2) would accumulate in the rumen and inhibit ongoing fermentation and digestion by negative feedback. Thanks to the methane emissions, ruminants can make use of the high fiber diet growing abundantly on the enormous terrestrial areas marginal to agriculture, and convert it into precious food for humans (meat and milk).

 

As long as there are no effective and inexpensive technologies available to manipulate the rumen metabolism in order to cut back the methane emissions without hampering the digestibility of fiber-rich diets, methane emissions seem to be the price for the very important contribution of ruminants to food security for humanity.

 

Has the omitted elucidation of this very important role of grazing ruminants been an oversight or was it done on purpose?

 

 

“Tackling Climate Change….” unjustifiably burdens grazing systems with ruminants, and in particular the beef industry of South America, with far too high emission values of GHG per kg CW. Due to gross negligence (omission of important baseline scenarios and of uncertainties in the appraisal of climate sensitivity to anthropogenic “GHG” emissions) and due to inconsistencies in the calculation and evaluation of specific emission values, this study will hardly be of a long lasting scientific merit.

 

However, the good reputation of grazing systems in general and the South American beef industry in particular has already been damaged (by the FAO!!!). Therefore the FAO should distance itself from this publication and withdraw it from its website.

 

I shall take the liberty of spreading this catalogue of questions (in German, English and Spanish) together with your answers among a carefully selected range of recipients of competent scientists, research institutes, policy makers, boards of producers, representatives of the beef industry, interested laymen and the media.

 

You may do the same within your professional environment. I should be grateful if you could deliver your answers also in the three languages, and if you could provide an acknowledgement of receipt briefly. Thank you very much in advance.

 

Kind regards,

Dr. Albrecht Glatzle

 

PS: You can find my latest presentation on the website of the Asociación Rural del Paraguay given recently at the “4º Congreso Ganadero” in Asunción. You will find further explanations and illustrations on the topics touched upon herein.

 

http://www.arp.org.py/index.php?option=com_content&view=article&id=841

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T{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}20GLATZLE.pdf

Aydin, M, Verhulst KR, Saltzman ES, Battle MO, Montzka SA, Blake DR, Tang Q and Prather MJ

(2011): Recent decreases in fossil-fuel emissions of ethane and methane derived from firn air. Nature

476 198-201

CSIRO (2013): Deserts ‘greening’ from rising CO2. http://www.csiro.au/Portals/Media/Desertsgreening-

from-rising-CO2.aspx

Quirk T (2010) Twentieth Century Sources of Methane in the Atmosphere. Energy & Environment 21,

251-265.