Bryn Glover samples the green future of food
HUMANITY faces a major challenge if we are to feed a global population of 10 billion by the end of the century. The simplest way to analyse the nature of this problem is to think in energy terms. Energy is measured in calories or joules and we’re all familiar with food packaging that tells us how many Calories or kilojoules our purchase contains. (The capital C of ‘Calorie’ means 1,000 calories – with a small ‘c’.)
But it is also necessary to consider how many joules of energy go into creating the foodstuff and transporting it to our plates. In his book How Bad are Bananas?, Mike Berners-Lee compares steak from Argentina to radishes picked from your garden. In the case of steak, beef is probably the least climate-friendly foodstuff we eat. Cattle produce meat with the least energy efficiency of any animal – less than 10% of the energy consumed, in any form, is converted to food.
The waste of food is scandalous. On the farm, vegetables considered misshaped and unsellable are destroyed and ploughed back. Upscale restaurants throw away massive amounts of unwanted material as they create finicky ‘plate-paintings’. Supermarkets pay strict attention to ‘sell-by’ dates and destroy much perfectly edible food. And in our homes we throw away a significant proportion of what we buy. Such examples of profligacy must simply cease.
So what about the future? The figures vary significantly across the western world, but in general, we are consuming energy at rates requiring four planet Earths to meet the demands of 10 billion people. Obviously a socialist solution must deliver equality of provision, so the mathematically unavoidable conclusion is that we all need to cut our current energy consumption by three quarters – and that applies as much to food as to everything else. Does this mean no more sirloins? Probably not – but it does mean that such dishes will come to be thought of, like turkey at Christmas, as a rare treat.
The simplest way to cut our food energy consumption would be for everyone to become vegetarian or, better still, vegan. This is unnecessary – our digestive system is that of a natural omnivore – but the more we can switch to a plant-based diet the better. The waste of energy in producing steak is the same with all farmed animal protein, including fish, where energy-rich food pellets have been expensively created from plant or (in the case of fish) other animal sources. Wild harvested meat or fish require no extra input but over-exploitation is a problem.
Our diet is sourced almost 100% from the animal and plant worlds. We pay almost no heed to fungi, bacteria and insects. Yet it is from these three that a much greater proportion of our protein requirements will need to be sourced in the future.
Humans have used fungi for millennia not only as occasional components of meals but also, indeed principally, as a means of leavening bread or creating alcoholic drinks. It is almost certain that in the future we shall turn towards products such as quorn – the basis of which is a mycoprotein derived from the fungus fusarium venenatum, combined with either egg albumen or potato protein as binders. Some people insist that fungal protein foodstuffs should be manipulated to resemble the animal meats they replace but perhaps that will diminish as familiarity increases.
Foodstuffs derived from bacteria are already familiar, including cheese, yoghurt, miso, kefir and kombucha, but they all require an original substrate upon which the bacteria go to work – milk, soy beans or tea – so that doesn’t help much. A small amount of work is progressing in which the bacteria are grown independently to be later converted into edible foodstuffs, but there is the small matter of the Second Law of Thermodynamics that tells us we never get something for nothing. If we expect bacterial sources to provide the energy we need to survive, then we must be clear about where the bacteria themselves will be getting their energy from in the first place. Some ideas involve the fermentation of waste food or of unusable plant material but we argue that wastes must be eliminated – and the first call on such as corn husks is to return them to the soil to sustain fertility.
A little laboratory work is underway to take small samples of animal muscle, and to induce their cells to grow rapidly into what can only be called sludges. Other research is attempting to persuade these sludges to take the form of what could be called meat. This may satisfy niche demands, but as possible total replacements for the thousands of tonnes of sirloins etc that are consumed daily, the idea is really a non-starter.
Ideas are being explored about exploiting the vast undersea forests of kelp that grow in our oceans, and these giant algae would certainly be capable of providing much human nutrition. It would, though, be a terrible idea if one considers the oxygenation and CO2 removal roles of seaweed; it is highly significant on a planetary basis. The lesson from the near extinction of North Atlantic cod would be that humanity is not capable of moderation where profitability is concerned.
The best innovations, however, occur in the insect world. Humans have tucked into insects for millennia, eating larvae (grubs) or imagoes (adults), which can be cultivated in vast quantities, killed, dried and powdered to create what is variously known as ‘insect flour’ or ‘insect paste’. These powders and pastes can then be worked into solid food items. Even so, that pesky Second Law comes into force, and any large-scale process will need to justify itself in energy terms; the insects need feeding, and that will inevitably mean vast acreages of special crops being grown for them. All processed foods require energy inputs, and these must be factored in to any assessment of desirability. Most people find the idea of eating creepy-crawliesrevolting, suitable only as a challenge on TV shows like ‘I’m a Celebrity’. Climate change is hardly a game but we may all have to undergo a bushtucker trial if we’re to get out of it.
Bryn Glover is a member of the AGS national committee