Thursday, November 23, 2017

Are pigs eating our food?

We are told that increased meat consumption is driving environmental destruction. But what if it is the other way round?

For each person on the planet, about 1500 kcal of plants is used daily to feed animals. In return we get just some 500 kcal per capita per day in the form of animal foodstuffs. The 1000 kcal that is “lost” in this transformation would be enough to feed another 3 billion people. Isn’t it a no-brainer that we rather should eat plants than animals? One could think so. But the reality is a bit more complicated than that. A recent paper from Anne Mottet, Livestock Development Officer, and colleagues from the FAO, Livestock: On our plates or eating at our table?, goes far in giving a better big picture understanding of the role of livestock in our food system.

“I came to realize that people are continually exposed to incorrect information about livestock and the environment that is repeated without being challenged, in particular about livestock feed,” says Anne Mottet. “There is currently no official and complete international database on what livestock eat. This study contributes to fill this gap and to provide peer-reviewed evidence to better inform policy makers and the public.”

The researchers have calculated the total feed intake of domesticated livestock (measured in dry matter) and as can be seen from the pie chart 46% of all feed are grass and leaves. The second most important feed are crop-residues (straw, stover etc.) with 19%, while grains (maize, wheat, barley etc.) account for 13% of the global livestock dry matter intake.  Other by-products from the food chain (in particular from the milling, drink and food industry) supply 5% of the feed, while oil seed cakes contribute another 5%. Notably, oil seed cake is partly a by-product as well. Global consumption of vegetable oil has skyrocketed after WW II and almost all vegetable oils have a waste production in the form of oil seed cake. Large scale cultivation of soybeans was first driven by soy oil demand, and still today soy oil is the second most important oil in the world and contributes one third of the income from soy growing.
Around 30% of the total acreage, some 210 million hectares, of cereal production is used for livestock feed, in addition 66 million hectares are used for the cultivation of hay, silage and other fodder crops. Together that makes 275 million hectares of land used for crops dedicated to feed production, slightly less than 20% of all arable land. If you add the proportion of feed coming from other crops (e.g. the straw or chaff from grain grown for food or oil seed cakes) one could consider that another 260 million hectares are used for feed production. But in the context of “people could eat what is eaten by animals” it makes little sense to add these as the alternative use of these residues and by-production is as energy, industrial raw materials or fertilizers and not food for humans. 

The study found that an average of only 3 kg of cereals are needed to produce 1 kg of meat at global level. But it also shows important differences between production systems and species. For example, because they rely on grazing and forages, cattle need only 0.6 kg of protein from human edible feed to produce 1 kg of protein in milk and meat, which is of higher nutritional quality. For backyard chicken and pigs only 0.1 kg of human edible protein is used to produce 1 kg of human edible protein while for industrial  systems between 2.9 and 5.2 kg of human-edible protein is used per kg of protein. By and large, traditional animal raising systems are an efficient way of producing high value food, which actually is quite self-evident as our ancestors certainly couldn’t afford any large scale waste of valuable food.

For ruminants, around one third of the protein in livestock products comes from pure grazing systems and 62% comes from mixed systems (system where animals graze to some extent, and where the feed has a considerable proportion of roughage) while only 4% of the ruminant protein come from feed lot systems. For poultry the situation is very different, where only 4% are estimated to be kept in backyard systems, i.e. small scale systems where animals are fed scraps, waste or find their own food here and there. One fourth of the pigs are raised in backyard systems and 56% in pure industrial systems. So poultry certainly eat food that people could eat, pigs as well to some extent, but ruminants are hardly guilty on a global scale.

While almost half of all livestock feed comes from grazing, because of low productivity of most grasslands huge areas are used for grazing. The statistics are notoriously unreliable, but the researchers state that the global area of grasslands is 3.5 billion hectares. Only 2 billion hectares, i.e. less than 60%, are grazed by domesticated livestock, however, the remainder is only grazed by wildlife, or not at all. The researchers claim that one third of this could possibly be converted to arable land. In the rest of the land the natural limitations are too big to allow for crop production. When I look at their map, however, I think their assessment is very optimistic. For example the map indicates that most of the southern part of Sweden has grasslands that could be converted to crop fields. While there certainly are such lands, my assessment is that most of what is classified as permanent grasslands in Sweden (not arable land which is grazed) is not convertible to cropping. 

Grassland, top ten countries 1000 hectares
China, mainland 392833
Australia 358962
United States of America 251000
Brazil 196000
Kazakhstan 187465
Saudi Arabia 170000
Mongolia 112364
Argentina 108500
Russian Federation 93000
South Africa 83928

It is important to consider the wider value of animal products in the diet. On a calorific basis they are “wasteful”, less so for protein as we have seen above. 40% of all dietary protein comes from animals (34% from livestock and 6% from fish and seafood). Around 45% of all dietary fat comes from animals and many of those fatty acids are unique for animal fat, and here there is no waste at all in feed conversion as animals get very little fat in their diets. Recent research in the USA, concluded that if the US food system changed into a vegan diet, there would be a huge increase in supply of calories and protein, but shortage in some essential fatty acids, vitamin B12 and vitamin A as well as Calcium.

While the focus of the paper is the role of animals in providing food, the researchers also point out that animals add to agricultural production through manure production and drought power. Further, keeping livestock provides a secure source of income for over 500 million poor people in many in rural areas. In addition, animal products are an important source of fuel and as an industrial raw material.  
We are told that increased meat consumption is driving environmental destruction. But what if it is the other way round? 
It is the constant increase in productivity of the worlds’ farmers, with the assistance of chemical fertilizers, pesticides, fossil fuels, breeding and technology that has created an enormous surplus of agriculture raw materials, in particular wheat, soy, maize, sugar and palm oil. 

There are no additional 3 billion people out there eating all that extra output. The surplus has driven prices down and made it possible to use grain for purposes which earlier were rare, such as bio fuels and animal feed. Under industrial farming conditions it is simply more profitable to use grown plants for feeding pigs and chicken than to have backyard systems. In almost all rich countries the acreage of grasslands are shrinking because it is “cheaper” and “more efficient” to give cows grown fodder and grain, despite the fact that grazing has very low direct cost and very low resource use. Since 2000 the global acreage of grassland has decreased with some 3% according to FAOSTAT.

By and large, the industrialisation of farming is the main driver of the expansion of livestock production. Under Swedish conditions a worker had to work eight times longer sixty years ago to earn the price of a chicken. No wonder global chicken consumption has increased 12 times in the same period!  

Thursday, November 9, 2017

Our food system - a health hazard

People get sick because they work under unhealthy conditions.
People get sick because of contaminants in the water, soil, or air.
People get sick because specific foods they eat are unsafe for consumption.

People get sick because they have unhealthy diets.
People get sick because they can’t access adequate, acceptable food at all times.

A recent report from the International Panel of Experts on Sustainable Food Systems identifies these five mechanisms whereby the current food system makes people sick.

The report calls for a reform of the food and farming systems to be made on the grounds of protecting human health.  Many of the most severe health are caused by core industrial food and farming practices, such as chemical-intensive agriculture; intensive livestock production and the mass production and mass marketing of ultra-processed foods. They are in turn stimulated by the deregulated global trade. 

Because of all interconnections in the complex food system it is not possible to always ascertain exactly the causes of a particular problem, but we know enough to act, according to the report. Even if the industrial food and farming model is not the only cause of the problems, it has clearly failed to provide solutions to them. The health effects are strongly linked to environmental effects and social issues. 

It is all too convenient for the industrial food system to place the responsibility of dietary choices with the consumers, when in reality they are the choice architects and they constantly influence consumers to consume highly processed foods made from a limited range of industrial raw materials. In addition they influence both research and policy for their own benefits.

The report make five key recommendations to adress the shortcomings of the current system.
  • Promoting food systems thinking;
  • Reasserting scientific integrity and research as a public good;
  • Bringing the alternatives to light;
  • Adopting the precautionary principle; and,
  • Building integrated food policies under participatory governance.
While there is nothing wrong with these recommendations, I find that they fall short of addressing the main drivers of the current system. As long as there is unfettered global competition, the drive to externalise costs will continue; the ever increasing specialization expressed as monocultures and industrial livestock systems will continue; the consolidation in the food chain will continue; the use of agro-chemicals will continue. As long as food is a commodity with its main purpose is to be consumed, the food industry's and retailer's incentive to make us consume more of processed food will continue.

Friday, November 3, 2017

Pissing in the rain?

I am busy with some research on glyphosate for some articles. The results are quite alarming I must say....

Tuesday, October 17, 2017

False methane math

Because of the difference in nature between methane and carbon dioxide we should cease expressing the climate effect of methane in carbon dioxide equivalents. This has important implications for policy as well as for the assessment of different strategies for minimizing the climate effect of production or lifestyles. Culling all cows may sound like a great proposition if we use the conventional metrics but is actually a rather futile effort to curb climate change.   

If you put ice in your drink it will cool off rapidly, but if it is hot in the air it will soon be warm again. That is perhaps the best way to describe the effect on the climate of a one-time reduction of methane emissions. It would give a rapid effect but after some decades it would hardly be noticeable. The same apply for a one-time increase in methane emissions, it leads to immediate warming, but the long term effect is small. This is very different from carbon dioxide, of which we hardly can measure the short term effects of a decrease or increase in emissions, but the effect will last for thousand years.  How can we then measure their climate effect with the same unit?

The most common way of comparing the greenhouse gas effect of different gases is to express them as carbon dioxide equivalents, i.e. how much carbon dioxide corresponds to a pulse (a one-time) emission of the gas in question. The most common way of expressing this is by the unit GWP-100, which express the cumulative forcing over hundred years. For methane (CH4) the GWP-100 value is 28, i.e. a pulse of methane emission of 1 kg corresponds to a pulse of 28 kg carbon dioxide emission. But we could equally use other figures as shown in the table below (from the IPCC Synthesis report 2014). For example the GTP-100 measures the actual temperature change after 100 years. With that measurement a pulse of 1 kg methane corresponds only to 4 kg of carbon dioxide. The actual effect on the temperature is probably more in line with what most people expect of the comparisons between greenhouse gases. 

But neither the GWP nor the GTP can properly reflect the difference between short lived greenhouse gases such as methane and long-lived carbon dioxide. In the article New use of global warming potentials to compare cumulative and short-lived climate pollutants in Nature Climate Change  Myles Allen and colleagues demonstrate how the calculations for expressing methane in carbon dioxide equivalents hides a lot of information. For short-lived greenhouse gases the comparison with carbon dioxide based on a pulse of emissions of both gases gives a reasonably correct result only in a time span of a few decades. In the longer term, the more correct comparison is between a pulse of carbon dioxide and an constant rate of [correted 13 nov] methane emissions. Or as expressed in the article

“The notion of ‘CO2-equivalent’ pulse emissions of cumulative and short-lived climate pollutants [SLCP, among which methane is the most important one, my comment] will always be ambiguous because they act to warm the climate system in fundamentally different ways. To date, this ambiguity may have had only a limited impact, not least because emission reductions have so far been relatively unambitious.”

… and

“GWP100  can be used in the traditional way, comparing pulse emissions of different greenhouse gases, to specify how mitigation of both short-lived and cumulative climate pollutants may reduce the rate and magnitude of climate change over the next 20-40 years, but only over that time. To achieve a balance between sources and sinks of greenhouse gases in the very long term, net emissions of cumulative pollutants such as CO2 need to be reduced to zero, while emissions of SLCPs simply need to be stabilised.“

The long term effect of a pulse emission of methane is thus very small after 100 years. What really matters in the long term is that CO2 emissions are cut dramatically. On the other hand, in the very short term, the effect of decrease in methane emissions is huge. It can be tempting for politicians or others who want to show quick results to focus on reduction of methane emissions and ”buy time” for the needed cuts in carbon dioxide emissions, or simply neglect it as the buck is passed to other generations.

A recent article in Energies by researchers from Chalmers University in Gothenburg makes the case that a culling of all domestic ruminants (they express it as a shift in diet to a non-ruminant diet, but that clearly assumes that all of them are slaughtered) would “buy us” time to delay the necessary transition of the energy system. But this one-time radical decrease of methane emissions doesn’t really take away the need for a fundamental change of the energy system, it just allows for a few years more of continued carbon dioxide emissions. After that we still need to cut them as much as without any cut in methane emissions.

The argument from the researchers why culling cattle is better than reducing carbon dioxide emissions is purely economic, it is simply cheaper in their analysis (which also assumes a 5% discount rate…). It is not clear how they calculated the loss of income for hundreds of million people and the loss of animal traction and transport for even more people, or how the loss of all the 187 million cows in India (12 % of all cows in the world) would even be possible. But I assume this is totally irrelevant for the researchers and their economic calculations. After all, in the big scheme, a rich European's trip to a tropical holiday resort has a higher “value” than the yearly income of an Indian farmer.

There is a case for a reduction in methane emissions to avoid that the climate reaches certain ”tipping points”, such as the melting of the permafrost. However, that argument only holds if carbon emissions are simultaneously reduced, thus not for the scenario where methane reduction is used to buy time as in the cull the cow scenario above. A cut in fossil fuels will also give a direct reduction of methane emissions as fossil fuel extraction is the biggest contribution to anthropogenic methane emissions. In addition, the climate effect of methane emissions from fossil fuels is higher than the methane from cattle, because the carbon in fossil methane adds to the long term carbon dioxide increase of the atmosphere while the carbon in the methane from ruminants is part of a biological cycle, and will be taken up by the grass eaten by the cows etc.


So much for the big picture, what about the emissions and grazing cattle? Do the more than hundred million people who primarily get their livelihoods from pastoralism or extensive grazing and their cattle, destroy the climate?   

If we see a ruminant and the pasture that feeds it, this is a balanced system where there is no increase in methane emissions. The methane emissions are just the same every year. As we seen above that will have had a small effect on the climate, meaning they have contributed to global warming. But equally important is that the methane emissions from these animals don’t cause a continued warming, the annual emissions are balanced by equally high breakdown of earlier emission. A lifecycle analysis, however, will treat this as a new system and each animal as an addition to emissions, i.e. a pulse emission in the GWP-100 metric, and therefore it will concluded that the cattle and its products cause huge emissions. This demonstrates that the results of a lifecycle assessment is determined by its assumptions and the metrics used, and why lifecycle assessments are not a good tool for use when assessing complicated biological systems.

But haven’t the number of ruminants increased rapidly? And haven’t huge areas been converted to pastures lately?

The number of cattle and buffaloes have indeed increased with 50% since 1961 (the human population grew with 135 % in the same period). Most of these additional cattle are fed with cultivated feedstuffs (silage, grains, corn, soybeans) either in US style feedlots for beef or in modern dairy production, i.e. they don’t graze. We have all heard the stories about massive tracts of land, often rainforest being converted to pasture. And it is true on a regional level, but globally there are also other trends where massive tracts of pasture is converted to forest or arable land. Most rich countries experience that pastures are converted to forests, for example in Sweden around 80 percent of all pastures have been abandoned the last 100 years. The global area of grasslands even shrank since 2000. Between 1961 and 2014 grasslands only increased with roughly 8 % globally.

Assuming that these lands were grazed by methane emitting ruminants already 1961, the net increase in methane emissions caused by grazing ruminants represent a very minor contribution to climate change, and most of the warming caused by these animals occurred long time ago. This doesn’t account for the laughing gas emissions (N2O) which is another climate gas. But it also doesn’t consider the sequestration of carbon in grassland soils. Both these merit own articles and are subject to huge scientific arguments.

To continue keeping these animals, keeping the pasture grazed, doesn’t contribute anything to further climate change. Culling them would – possibly --  result in a one-time small reduction of global warming, hardly noticeable for future generations*  If it is worth it, is a question of values and of which food system we favour, and not a strategy for tackling climate change.   

*If the land were converted to arable farming it would emit more carbon which would cause more global warming.