Mike Redwood


International Leather Maker

In 2013, the world produced 5,935 kcal of crops per person per day that could be consumed by humans, and an additional 3,812 kcal of vegetable matter for animals. What was truly available for human consumption after taking out food waste and loss animal feed and industrial use as well as changes in stocks, was even lower. By 2016-18, a global average of 2,908 kcal were available for daily human consumption. This had risen from 2,330 kcal 50 years earlier.1

This was brought when I read Gaia Vince’s 2022 book Nomad Century. Climate change books can be difficult because the subject matter is now so politicised. It is impossible to read about the subject without seeing the position of the author coming through. This book focuses on human migration relates to actions needed, starting now, to obtain manageable outcomes with the temperature changes that are already occurring or now appear certain to occur in the future. Whatever your position on climate change, it is a must read as change is all around us already.

Discussing the food requirement issue, Vince slides into the normal trap of condemning livestock, but her figures are revealing as she adds to the data above. She reckons that, globally, each person needs 2350 kilocalories per day to stay healthy, and she shows that, after all the waste and livestock usage, there are now 2530 kilocalories left per person. Because regional unevenness screws things up, we have the U.S. producing eight times what it needs while 850 million people, and rising, go hungry.

Food waste in mature markets is about careless over-consumption aided by cheap offers like “buy one, get one free” and nonsensical sell by dates. In emerging markets, there is a lack of warehouses to store harvests near the fields, along with poor infrastructure, and crops can lie wasting on the land in the north of a country while food aid is flown in from overseas to feed the south. Not very clever in the 21st century.

Crops to feed livestock

Amounts of food grown to feed livestock are problematic. Figures never show the split between animal types. How much goes to poultry, where leather is not involved, or for pigs, whose skins are increasingly left on the meat to be eaten? Equally, some crops are split with high value grains going for vegetable oils and only the waste to animal food. Other crops are, of course, used entirely for livestock feed.

Similarly, land use for livestock appears to be calculated in highly general terms. We know that much of the land used for livestock is unsuitable for crops. It is too hilly, too rocky or too marshy. Some argue that if it is not suited for crops, livestock land should be planted with trees, but Vince herself makes it clear that tree planting does not often work out. The wrong types of trees are used and wildfires are increasing every year. In most instances, long-term grassland is better for carbon sequestration, water retention and biodiversity.

Long-term grasslands

This brings us to our next reality. For long-term grasslands to work, they need dung beetles which need cattle and the weight from cattle hooves to press the CO2 into the soil so that the deep-rooted plants can move it into the underground micro-biome. When the world converted from mixed arable and livestock farming in the 1940s and 1950s, we forgot about this vital biome and let it suffer while chemical fertilisers were introduced.

To keep an artificial fertiliser regime working requires huge amounts of CO2 but does not support good health, so the crops then require pesticides and sprays against weeds and disease. To stop this degeneration, a return to a better crop rotation system and the introduction of livestock for fertilisation and carbon sequestration is required. Depending on the degree and nature of the degradation, this “regenerative” farming can take various forms but all quickly aid biodiversity, better quality soils and the production of more food of better quality.

In terms of land use, we should not ignore the large amounts of good quality agricultural land being used for solar farms, indoor chicken sheds, biofuel crops, cut flowers and permanently removed for urbanisation. The world is full of industrial estates and large car parks better suited to solar panels and associated wind turbines.

Evidence from California shows that most livestock farms can further reduce methane emissions through feed supplements and making use of slurry. Readers following the Glastonbury 2024 music festival will be pleased to know that Worthy Farm has for some years been using its cow slurry in an onsite anaerobic digestion facility to generate biogas. It will now use some of that biogas to produce graphene (used in modern batteries and tyres) and hydrogen. The generated hydrogen will be used in Worthy Farm’s Combined Heat and Power (CHP) plant, cutting the farm’s annual greenhouse gas emissions by up to 25 tonnes.

It is now recognised2 that, with the newly calculated population trends, the world can feed itself going forward but some changes are needed. Honest calculations and a willingness to work for compromise rather than extreme antagonism would recognise that livestock still has an essential role to play.


  1. https://www.globalagriculture.org/transformation-of-our-food-systems/book/infographics/availability-of-calories.html
  2. Berners-Lee, M, et al. 2018. Current global food production is sufficient to meet human nutritional needs in 2050 provided there is radical societal adaptation. Elem Sci Anth, 6: 52. DOI: https://doi.org/10.1525/elementa.310


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