Changing our diet for a wilder world

Status: early draft

This short essay explores how a plant-based or vegan diet could drastically transform our land use to improve and protect biodiversity by allowing the creation of new wilderness areas.

It will be focused on Western Europe (Austria, Belgium, France, Germany, Liechtenstein, Luxembourg, Monaco, Netherlands, Switzerland) using data from the Food and Agriculture Organization (FAO) of the United Nations, but it could easily be transposed to other industrialized regions. All tables were generated by a script published on GitHub.

Population

Paris Paris, France (Google Maps)

Western Europe was home to 191 million humans in 2013 and that number should stabilize around 200 millions by the year 2040. At the same time 573 million chickens, 65 million pigs and 42 million cattle, among other animals, were kept in farms to feed them.

Item Population
Humans 190.51
Livestock 765.51
.. Pigs 64.54
.. Cattle 41.85
.. Sheep 11.07
.. Goats 2.04
.. Chickens 572.72
.. Turkeys 35.14
.. Ducks 30.08
.. Other 8.08

Land Use

Pine Plantations Pine plantations, Landes, France (Google Maps)

Western Europe has a land area of 109 million hectares. Most of it was covered by deciduous trees before human settlement and the beginning of agriculture, but nowadays the forests are reduced to 34 million hectares while crops and pastures use 28 and 25 million hectares respectively.

A closer look at the current forests shows that there is virtually no wilderness left in Western Europe, it is one of the most endangered ecosystem in the world. The vast majority of the remaining forests are heavily exploited and about a third of them are not much more than monoculture tree plantations.

Item Area
Land 108.52
.. Crops 28.48
..... Permanent crops 1.35
..... Temporary crops 26.40
..... Fallow land 0.74
.. Pastures 24.55
..... Permanent meadows and pastures 17.83
..... Temporary meadows and pastures 6.72
.. Forests 34.44
..... Primary forests 0.16
..... Planted forests 9.97
..... Naturally regenerated forests 24.31
.. Other 21.05

Most cattle (and sheep and goats) live in pastures, while most chickens and pigs (and humans) live indoors. Crops produce food for both humans and their livestock.

Crops

Cereal fields Cereal fields, Beauce, France (Google Maps)

The majority of the space taken by crops is used for cereals, representing 18 million hectares of plantations, with 4 more used to produce oils. The remaining plants (fruits, roots, vegetables) take less than 3 million hectares.

Item Prod Area
Crops 269.31 25.38
.. Cereals 125.79 17.56
.. Oils 12.60 4.03
.. Fruits 13.12 1.18
.. Sugars 71.84 0.95
.. Roots 27.65 0.67
.. Vegetables 16.13 0.51
.. Pulses 1.10 0.32
.. Fibres 0.55 0.08
.. Nuts 0.08 0.04
.. Spices 0.03 0.02
.. Drinks 0.41 0.01
.. Other 0.02 0.01

NOTE: The area of crops on this table (25M hectares) differs from the previous table (28M hectares), see: QC Methodology (FAOSTAT)

The following table is more complex, but it allows us to see how many million tonnes of a type of crop is used for human food (directly or processed) and livestock feed.

Item Prod Supply Proc Food Feed Other
Crops 303.17 315.21 111.00 100.82 65.44 38.23
.. Cereals 125.96 104.03 9.70 22.05 60.52 11.76
.. Sugars 71.82 72.15 66.43 0.00 0.00 5.72
.. Roots 27.61 20.32 0.92 11.99 1.77 5.64
.. Drinks 24.57 24.24 0.85 21.36 0.00 2.04
.. Oils 21.78 40.55 24.87 4.27 1.99 9.58
.. Vegetables 17.02 21.42 0.00 18.72 0.40 2.36
.. Fruits 13.25 29.92 8.24 20.66 0.00 1.05
.. Pulses 1.09 1.21 0.00 0.40 0.76 0.06
.. Nuts 0.07 1.16 0.00 1.15 0.00 0.02
.. Spices 0.00 0.20 0.00 0.22 0.00 0.00

NOTE: Some items on this table differ from the previous table. For example beers and wines are now excluded from cereals and fruits respectively and counted in drinks.

Most of the crops used to feed livestock are cereals. Of the 104 million tonnes available in the domestic supply, about 1/3 goes to human food and 2/3 to livestock feed.

Furthermore, as supply is defined by production + import - export - changes in stocks, assuming the same balance for the 126 million tonnes of cereals produced, about 11 million hectares of cereal crops out of 18 according to the previous table are used to feed livestock.

Diet

Cattle in a pasture Cattle in a pasture, Alps, France (Google Maps)

If we look at the food supply (in kcal/capita/day) we can see that animal and vegetal products represent respectively 1/3 and 2/3 of the diet in Western Europe.

Item Calories
Animal Products 1109
.. Meat 514
.. Dairy 492
.. Eggs 49
.. Seafood 54
Vegetal Products 2387
.. Cereals 882
.. Oil 483
.. Sugar 431
.. Drinks 219
.. Fruits 117
.. Roots 114
.. Vegetables 74
.. Nuts 40
.. Pulses 19
.. Other 8

Plant-based diets have a long history around the world and the modern widespread availability of dietary supplements (vitamins B12 and D most notably) means that a strict vegan diet, properly planned, can be as healthy as any omnivore diets.

In terms of calories available to humans, converting crops to animal products is less efficient than directly consuming those crops in the first place, so a much smaller area of land for crops would be needed. The same might be true for other products like beers and wines for example.

NOTE: Add numbers and references to the previous paragraph.

It should be noted that some areas used for pastures are not suitable for crops and in those areas a diet including some animal products might be more efficient from the point of view of maximising the number of humans living on the land. But this essay is about improving biodiversity while stabilising the current human population of industrialized regions like Western Europe.

Conclusion

Bialowieza Forest Bialowieza Forest, Poland (Google Maps)

If all humans living in Western Europe shifted to a plant-based diet, most 25 million hectares of pasture and at least a third of the 28 million hectares used by crops (mostly cereals used to feed the livestock) could be freed from agriculture, while a smaller portion of that cropland would be kept to increase the quantity of vegetal products available for direct human consumption. The result of this change, after rewilding the land, could double the amount of forests and provide a lot of space required to protect biodiversity.

A full conversion of the population to a plant-based diet seems, of course, slightly utopian at the moment, but even a moderate shift toward less meat consumption would progressively allow the creation of more natural reserves.

Annexes

Below are the same tables generated for the whole world (FAOSTAT 2013), mostly equivalent to this great data visualization from Our World In Data.

In less industrialized areas there are more remaining forests, crops take less space than pastures and are less used to feed the livestock, and humans eat less animal products. But the population is still growing and adopting more and more a lifestyle similar to Western Europe.

World populations (in millions):

Item Population
Humans 7,213.43
Livestock 28,156.90
.. Cattle 1,434.40
.. Pigs 976.34
.. Sheep 1,132.72
.. Goats 954.72
.. Chickens 20,955.42
.. Ducks 1,111.52
.. Turkeys 450.87
.. Other 1,140.92

World land use (in million hectares):

Item Area
Land 13,021.25
.. Arable land and permanent crops 1,571.97
.. Permanent meadows and pastures 3,309.64
.. Forests 4,005.75
..... Naturally regenerated forests 2,437.26
..... Planted forests 286.93
..... Primary forests 1,281.56
.. Other 4,133.88

World crops areas (in million tonnes and hectares):

Item Prod Area
Crops 8,665.04 1,400.50
.. Cereals 2,768.02 722.32
.. Oils 809.58 261.92
.. Pulses 77.97 80.01
.. Fruits 823.66 63.56
.. Roots 817.52 61.46
.. Vegetables 997.84 54.52
.. Other 97.05 48.77
.. Fibres 78.59 35.32
.. Sugars 2,150.31 31.39
.. Drinks 19.18 24.34
.. Nuts 14.93 11.13
.. Spices 10.37 5.77

World crops balance (in million tonnes):

Item Prod Supply Proc Food Feed Other
Crops 8,436.27 8,289.18 2,191.64 3,532.90 1,196.12 1,376.78
.. Cereals 2,523.35 2,407.01 94.58 1,029.02 873.55 410.48
.. Sugars 2,126.84 2,128.23 1,593.75 32.25 39.74 462.50
.. Vegetables 1,129.61 1,124.93 0.24 982.97 51.71 90.41
.. Roots 811.32 815.70 15.44 443.35 175.29 181.80
.. Oils 753.37 726.49 431.79 131.50 40.20 128.35
.. Fruits 662.13 661.60 53.30 544.88 2.45 62.08
.. Drinks 315.13 312.24 2.53 279.48 0.00 30.49
.. Pulses 82.67 81.50 0.00 59.20 13.19 9.22
.. Nuts 16.93 16.80 0.00 16.41 0.00 0.57
.. Spices 14.94 14.68 0.00 13.85 0.00 0.89

World diet:

Item Calories
Animal Products 514
.. Meat 273
.. Dairy 170
.. Eggs 36
.. Seafood 35
Vegetal Products 2371
.. Cereals 1292
.. Oils 331
.. Sugars 237
.. Roots 142
.. Fruits 98
.. Vegetables 96
.. Pulses 79
.. Drinks 75
.. Nuts 16
.. Other 5

References