Professor John Parham, Course Leader for the Arts and Humanities MRes programme and the English MA, talks to us about the cultural history of photosynthesis 


The first Covid lockdown, April 2020. A friend kindly posted us some pea seeds for our balcony. They produced a tiny, organic crop; we got a half portion each. We dried the few remaining stragglers, replanting them in 2021. I wasn’t particularly hopeful, but in a ceramic pot, as if from nowhere, shoots burst from the soil. This act is the ultimate statement of being. The poet Alice Oswald describes leaves unfurling in ‘a gradual fleshing out of a longing for light’. It’s the magic of photosynthesis and I’ve been thinking about it ever since. 

pea plant

My partner tried to help me memorise the scientific formula for photosynthesis. Without success. Later, they scribbled it down. In a Greek restaurant, enjoying the food of a country where the sun is always let in, the penny dropped. Water and carbon dioxide, catalysed by sunlight acting on chlorophyll (the pigments which make plants green), produces a form of sugar called glucose. With a side order of oxygen.

Without plants, we’d have nothing to eat. Without oxygen, a by-product of photosynthesis, we couldn’t breathe. An hour of sunlight falling on Earth is equivalent to the energy humans consume in a year. Utilising photosynthesis – through ingenious crops, carbon-neutral biofuels, carbon-capturing seagrass – could meet our demands forever while helping tackle climate change, population growth, energy crisis. Yet photosynthesis is under threat, from rising levels of atmospheric carbon dioxide, land clearance, forest fires, floods and drought.

Mother and child
Mother and Child, an artwork grown in grass, by Ackroyd & Harvey

We should understand photosynthesis better and appreciate it more. Appreciation is where culture steps in. There are more games, poems, and artworks about photosynthesis than you can imagine. Computer games can teach you about photosynthesis. However, if you wander unsuspectingly into an art space, Heather Ackroyd and Dan Harvey’s 6 foot ‘Mother and Child’ could stop you in your tracks. Aware that differing levels of light regulate the production of chlorophyll Ackroyd and Harvey create, from grass, all-too human images. They remind us of the wonder of photosynthesis, of where and how we came to be. 

Occasionally I run marathons. Such distances, not necessarily natural to humans, require careful uptake and output of oxygen and eating well (not too much, not too little). On long runs, you might need energy gels or drinks. Pumping our arms activates that energy; breathing is complemented by the passage of glucose through the body.

In 2021 I ran my first Park Run. I was marathon training, testing my speed. Pushing hard, I was highly conscious of how efficiently I was drawing breath, how much sugar I had available to burn, whether these reserves would push me through a final, punishing mile. These things I take for granted can be harder still for others. I’m not quick. I laboured to overtake a parent and their daughter. Running at a pace no ten year old should have been running at, the daughter was struggling. And complaining. ‘Keep your breathing steady’, said mum. One day, perhaps when she’s an international athlete, the daughter will be grateful for the advice. This morning it didn’t seem to help. Breathing cannot be taken for granted when the body is under stress.   

Solar farming

‘I can’t breathe.’ For novelist Ben Okri, those words resonated horribly because, he wrote, the experience of not being able to breathe is now dangerously close to becoming the ‘condition of the world’: ‘To deprive someone of air is to deprive them of their humanity’. Such a fate grimly unites George Floyd (and others) with victims of Covid-19. Shortness of breath is, too, a symptom of panic attacks, which themselves can be a symptom of mental health or the pressures of modern life. After withdrawing from Wimbledon in 2021, Emma Raducanu said ‘I found it very difficult to regulate my breathing’ because of ‘everything that’s gone on over the past week’. Breathing difficulties are also a symptom of climate change. Smog drapes cites like Shanghai or Santiago de Chile. Nitrogen oxide, from cars and factories, compounds from gasoline or cleaning solvents, damage lungs and exacerbate asthma. In forest fires people usually die not from fire but asphyxiation.

In Scots and Roman Law a precarium is a gift which can be revoked or recalled at will. In medieval times, conquering armies redistributed land as a precarium to reward supporters or place people in their debt. Photosynthesis is our precarium. Without it, we’ll never breathe again.

But this isn’t a blog about the end of the world. Because of photosynthesis, we still have seagrass, pea plants, solar panels. We can breathe. Art, computer games, poetry, our own lives remind us of what a wonderful gift this is.

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