THE FORESTS OF ANTARCTICA
The poles were not always frozen year-round. Up until relatively recently (in the history of the planet, obviously not in human timescales) there were trees on Antarctica. Antarctica hasn't moved very much from where it is now (it was close to its current position at the time Pangaea still existed) so the trees and the ecosystem that came with them were able to survive despite the absence of sunlight for half the year. The trees all became extinct when the poles became permanently encased in ice.
Some day, the poles will melt and life will be able to live on Antarctica again. That could happen at a time when the human species still exists, if we fail to limit anthropogenic climate change. Or it could happen despite anything we do, because of something out of our control, or if it turns out climate change is a chain reaction that has already gone too far and reached a critical mass from which nothing we can now do will reverse.
If Antarctica becomes capable of supporting complex life, what will grow and live there? We could of course just leave it alone and an ecosystem will eventually evolve to fill that niche, but that would take a long time and the obvious and ethical solution would be to use it to provide homes for people displaced by coastal flooding due to rising ocean levels from the polar ice melting. What will the people be able to eat when it is dark for half the year?
LATITUDE AND GROWING SEASONS
In regions with long dark winters such as Scotland and the Scandinavian countries, there is a reason why traditional meals are usually things like fish or haggis with root vegetables. It is not possible at these latitudes for people to get sufficient nutrition from the sorts of crops that can grow in the climate there. People have to farm hardy livestock as well as crops if they are to survive without relying on imports.
GREENHOUSE GASES i.e. METHANE
The most common objection to grazing animals from an environmental perspective is that the animals themselves produce greenhouse gases (most commonly, that ruminants produce methane).
However, this is a simplistic and incomplete part of a complicated and not completely understood system.
Methane has a half-life in the atmosphere and will break down into carbon dioxide after about 8 years. As long as net emissions of methane remain roughly constant over time, and vegetation utilises the carbon dioxide, the environment can absorb them. Many natural and unnatural processes emit methane, some of them beneficial in other ways. Bogs and peatland are some of the few environments in existence today that can continue to capture carbon indefinitely due to the remains of plants and animals building up in conditions where decomposition can't properly occur -- rather like the vast swamp forests of the Carboniferous but on a smaller scale. The anaerobic processes that do affect this organic material emit methane, notoriously as the 'will-o'-the-wisp' swamp gas phenomenon. Methane produced from the decomposition of sewage and refuse, or indeed any non-fossil source of methane, if it could be collected, could be used as a renewable replacement for gas. There would be a small, but not insignificant, reduction in pollution from both agriculture and the funeral industry if we could stop incinerating dead people and animals and abattoir refuse, and biodegrade this material efficiently and hygienically into compost and captured methane.
Properly managed grazing land stores carbon and resists soil erosion. Using land for growing annual crops exacerbates soil erosion and emits carbon. It turns out to be rather difficult to measure and quantify the emission or storage of carbon in soils, however, and shockingly most of the calculations released to the public fail to take this into account. What stores the most carbon on land is situational as in some climates and soil types it's possible to create grassland where planting trees wouldn't work, and in some cases grasslands might actually be the best option for sequestering carbon. When it can be accounted for, grazing livestock is likely to look somewhat to a lot better compared to crops than how it is currently portrayed.
When it's considered that the carbon in grazing systems as well as in typical crops that people can eat isn't as simple as it might be presented, that grazing can be used to restore land depleted by crops, and that growing crops becomes more difficult if not ultimately unviable without livestock farming, and that a lot of land in the UK and other countries of similar latitude used for livestock grazing cannot grow crops suitable for people in any shape or form, it should be apparent that it is all part of a system and that no one part of it can be considered apart from the rest of it.
A conserved prairie in Texas. Prairies are natural grasslands found in the USA. They were originally grazed by large ruminants such as bison and were biodiverse habitats. As prairies are rich fertile soils, farmers ploughed them up to grow crops and unfortunately over many years soil erosion and carbon loss has meant the soils have become infertile. Restoring prairie to its natural state and properly managing it with grazing livestock instead of using it all for crops will store carbon.
BIODIVERSITY AND BALANCE
It can seem we are sometimes encouraged to think of things in terms of 'min/max'. For example, growing a particular crop might mean feeding the largest number of people on the smallest area of land, or using the same land to grow a particular species of tree would store the most carbon, or creating a tidal marsh on it would mean the most biodiversity. The reality is we need to use land in varying ways to achieve a compromise between feeding people and reducing emissions and sequestering carbon and promoting biodiversity.
A perennial crop such as an orchard is probably the best way to farm and store carbon, but orchards often are also planted with grass. The grass can include wildflowers to benefit nature and livestock can also graze it. The grazing of livestock means less energy needs to be used to cut the grass and prune the trees and keep in check plants that can become a nuisance like ivy and 'old man's beard'. Animals benefit trees by trampling undergrowth and breaking up debris and fallen branches, allowing light in and air to circulate. Hedges and copses for livestock to shelter provide habitats, and traditional hay meadows and leys can be havens of insect biodiversity. Ground damaged by crop-growing can be turned over to grazing and rejuvenated so in future it can grow crops for people to eat once more.
There are some people who think we should turn over as much land as possible to wildlife and reintroduce x and y large mammalian species because they once existed here and have been extinct for centuries. This exotic image of a 'perfect wilderness' is simply a romanticised snapshot of one particular point in time that is by no objective calculation better than any other point in time, and ignores the necessity of providing food for people. If species have become locally extinct, it means the native subpopulations or subspecies native to that locality are lost for good. Importing animals from other populations will not restore its unique genetics. Species should not be reintroduced unless their absence causes a problem with the ecosystem that can't be fulfilled by something else. Domestic goat and sheep breeds serve the same purpose on moors and mountains as their primitive wild ancestors, and there is no need to reintroduce wild boar in woodlands when domestic pig breeds can be used for the same ends. However, creating habitats to encourage pine martens to re-establish in England and Wales will benefit the ecosystem as they control the non-native grey squirrel population and the damage it does to trees, and nobody seems particularly interested in eating the squirrels and we don't have another predator that can fill that niche.
The Nazis did an experiment to try to recreate the extinct ancestor of modern cattle, the aurochs. They took over large swathes of forest in the countries the Nazis had invaded (presumably murdering or displacing the local farmers and the breeds of livestock unique to the areas) and filled them with cattle of various breeds which they believed had characteristics that would recombine to create the traits of the extinct species from which they evolved -- an enormous, aggressive wild animal. This was because of a quasireligious pseudoscience and absence of knowledge of genetics at the time, which caused the Nazis to believe enormousness and aggression to be more spiritually valuable than the useful traits instilled into livestock by generations of careful selective breeding such as docility, hardiness, production, and ease of management. The results of this experiment, although they were large and aggressive, failed to match the size and phenotype of the original aurochs, and of course failed to recreate the gene pool of the breed that the Nazis didn't have the science to understand. This is because the genetics of a species or breed cannot simply be reassembled once it is lost even if fragments of it survive in extant animals. The genome is so large and chromosomes recombine so randomly that it cannot be done. As for the cattle themselves, when the Nazis were defeated, the local people hunted and ate most of them. Ironically, although they weren't aurochs, they shared the same fate. A small number of them survive as a breed now called Heck cattle, which have little use compared to other cattle breeds because of their aggression.
Creating artificial nature is a vanity of the wealthy and powerful imposed upon the poor and the powerless.
No discussion of ethics would be complete without an assessment of the welfare of the animals being farmed.
To do that, we have to compare domestic animals to nature. That's not because of any misconception that nature is somehow perfect, because nothing is perfect and perfection and worlds in which nothing ever dies are a man-made fantasy, and it is impractical and unreasonable to compare anything in real life to this standard. Nature is what exists that we can't control, and has always existed and will continue to exist even if we no longer do, so in order for something to be ethically justifiable, it has to be at least as good as nature and preferably better. For this argument I'm considering animals used for grazing (typically ruminants) as they are kept in the UK, i.e. in pastures, because they can be used for conservation grazing and that's what this series of blog articles is about, and not animals that are factory farmed indoors such as pigs and poultry. Pigs and poultry can however be farmed in ways that are beneficial and higher welfare, but that is something to discuss in another post.
Link: The Five Freedoms
Mammals embody a specific evolutionary strategy. One sex competes amongst itself for a limited right to reproduce. The other faces no barrier to reproduction, but invests all of its resources into having and raising young. Both sexes of mammal risk starvation, predation, exposure, disease, and injury in the wild. Male mammals typically compete by fighting and can be harmed or killed in the process. Even the successful males tend to have limited tenure; a few breeding seasons at most in his prime before exhaustion and advancing age ensure his defeat and obsolescence. Wild female mammals typically face pregnancies too young, too old, or too frequent to permit full recovery. They face birth in dangerous situations with no medical recourse if something goes wrong. They experience the deaths of many of their young. Prey animals are typically chased, terrified, and subjected to violent and drawn-out deaths by predators, or swallowed and digested alive in the case of many insects and small fish. Predators frequently starve to death due to injury or simply not being competitive enough at hunting.
Conversely, if we consider domestic mammals such as sheep, it should be obvious they do not face these difficulties to anywhere near the same extent. Even the most money-motivated sheep farmer will ensure the sheep are properly fed and and treated if they get diseases, as malnourished and sickly animals are unsaleable and won't produce healthy offspring, and deadstock costs money to dispose of. Unwell animals are treated with veterinary medicine, or euthanised if this is impossible. Male animals are selected for breeding and those who are not selected are either castrated and kept as pets or taken to an abattoir and stunned before being slaughtered. The tups who are kept for breeding will be moved in with the ewes at the mating season and moved out afterwards and kept elsewhere. The tups will never have to fight for access to ewes. Any ewes who are not in suitable condition to be mated will be kept out of the breeding group for that year. When the ewes are due to lamb, most farmers will bring them into a shed and observe them carefully, summoning a vet if needed, and will ensure the lambs get the best possible chance of survival.
Therefore, even when taking into account that accidents sometimes happen and animals can't be supervised around the clock, and problematic exemptions such as religious slaughter without stunning, grazing livestock irrefutably has better welfare than wildlife, and farming grazing mammals such as sheep is ethically defensible.
One issue with promoting how we farm in developed countries is that people in developing countries often seek to emulate it, even when it's not suitable for the environment they live in, and might do things such as tear up rainforests so they can create swards of plants unsuited to their climate so they can graze Western breeds of sheep. Unfortunately, traditions which often developed over many centuries for good reasons are wrongly seen as irrelevant, unfashionable, or even (foolishly) politicised and derided as xenophobic. It's vital when discussing conservation that we stress the reasoning behind it, which is that sustainable farming is a system tailored to its environment and specific to that environment. In every part of the world, when seeking to farm sustainably, people must look at the breeds and crops that are traditional to the heritage in that particular place and the methods traditionally used there.
Because food has unfortunately become so politicised, I have spent the first three blog posts in this series doing groundwork that I hope will help readers to understand the complex science and reasons behind traditional mixed farming that are too often presented as facile, politicised arguments. In the next post in this series, I hope to finally get into the exciting matter of what grazing or 'grass' actually is in terms of plant species and biodiversity!