Whether human beings survive this century and the next – whether other lifeforms can live alongside us: more than anything this depends on the way we eat.
We can cut our consumption of everything else almost to zero and still we will drive living systems to collapse – unless we change our diets.
All the evidence now points in one direction: the crucial shift is from an animal- to a plant-based diet.
A paper published last week in Science reveals that while some kinds of meat and dairy production are more damaging than others all are more harmful to the living world than growing plant protein.
It shows that animal farming takes up 83% of the world’s agricultural land but delivers only 18% of our calories.
A plant-based diet cuts the use of land by 76% and halves the greenhouse gases and other pollution that are caused by food production.
Part of the reason is the extreme inefficiency of feeding livestock on grain: most of its nutritional value is lost in conversion from plant protein to animal protein.
This reinforces my contention that if you want to eat less soya then you should eat soya: 93% of the soya we consume – which drives the destruction of forest – savannah and marshland – is embedded in meat – dairy – eggs and fish and most of it is lost in conversion.
When we eat it directly much less of the crop is required to deliver the same amount of protein.
More damaging still is free-range meat: the environmental impacts of converting grass into flesh – the paper remarks ‘are immense under any production method practised today’.
This is because so much land is required to produce every grass-fed steak or chop.
While much of this pastureland cannot be used to grow crops it can be used for rewilding: allowing the many rich ecosystems destroyed by livestock farming to recover – absorbing carbon dioxide from the atmosphere – protecting watersheds and halting the sixth great extinction in its tracks.
The land that should be devoted to the preservation of human life and the rest of the living world is at the moment used to produce a tiny amount of meat.