Just as the first lockdown was beginning to lift in late summer 2020, Tom Bullough set out to walk Sarn Helen, the Roman road that once cut through Wales from Neath in the south to Caerhun in the north. It still does, although there are places where you would be hard pressed to see it, places where it wobbles, turns a corner or generally behaves in a most un-Roman manner. The road gets its name from the fourth-century princess turned saint, Elen Luyddog, who, according to the Mabinogion, insisted that her Roman husband, Magnus Maximus, build her “a great road” linking her home town in the foothills of Snowdonia all the way to the Bristol Channel.
Sadly, the timings don’t work. The Romans laid down their roads shortly after settling in Britain in the first century, long before the historical Elen was in any position to start making demands about infrastructure. Still, it is these layering, time-shifting stories that Bullough holds in his head as he pulls on his boots, packs blister plasters and prepares to be nibbled to death by midges along the 160 miles of what translates into English as “Helen’s Causeway”. A few days in and he ruefully recalls a story about how the legionaries who built the road found their sandals lasted only a week. His feet, let alone his boots, feel as if they might be heading the same way.
Born and bred on the English-Welsh border nearly half a century ago, Bullough, who is a novelist, understands more than most the patchworked nature of Wales. How, for instance, the English language is all that has been heard in his native Radnorshire (now part of Powys) for the past 300 years, yet scoot six or seven miles over the county line into Cardiganshire and it’s mostly Welsh. And how, when you are on the west side of the Cambrian Mountains, the idea of Welsh independence seems entirely logical, while in the rich hedged meadows around Hay-on-Wye it may be regarded as eccentric posturing.
In the same way, the landscape itself contains multiples. You can be walking past a cluster of yews that are older than Christ, turn a corner and find yourself in a standoff with a herd of alpacas. As Bullough presses on through the guts of the country he encounters Roman hill forts guarding post-industrial villages and natural springs bubbling up in the middle of housing estates. Sometimes the timeshifts are crammed into a single building: a nonconformist chapel is turned into a bijou domestic home by the incongruous addition of a front porch that appears to have been filched from a county hall.
In other ways, though, suggests Bullough, it can be helpful to think of Wales as a whole, rather than endlessly parsing it into pieces. He points to the way that the country frequently functions as a handy unit of measurement. Turn on the BBC News and you will soon learn that an iceberg is “quarter of the size of Wales” or that the wetlands of South Sudan are “two times the size of Wales”. It also figures as a measure of loss: between August 2020 and July 2021 an area of Amazonian rainforest half the size of Wales disappeared. Or, as one of the environmental scientists Bullough speaks to says, “you can get your head around Wales, when a lot of this stuff can be just overwhelming”.
It is Wales as a manageable imaginative space that Bullough leans into. For if he can show us how Wales is faring in these environmental end times, then we might just be able to scale it up until we arrive at a proper reckoning of the damage inflicted around the world. He starts with personal observations of what has disappeared within his own lifetime. Gone are the house martins under the eaves, and if you glanced a red squirrel out of the corner of your eye, that was probably wishful thinking. Also on the list of vanishing creatures are the puffin, the water vole and something called “Bechstein’s Bat”. Bullough’s text is illustrated by beautiful monochrome paintings by Jackie Morris of 15 of the most endangered animals and plants.
One of the species that you won’t find on the endangered list is humanity, but that doesn’t mean that the outlook is good. About 60% of the Welsh population live on the coast, yet relentlessly rising sea levels mean that the country is fraying at the edges. Fairbourne, on the south side of the Mawddach estuary not far from Saint Elen’s home, is the first village in Britain expected to be lost to climate change.
Bullough speaks to a series of environmental scientists, mostly based in Welsh universities. Some are so sad that they seem about to weep in the middle of their Zoom calls. Others are frustrated by a continuing misapprehension among the public. While thinking about Wales in relation to global heating can sound funny – what could be nicer than turning up the thermostat on the country’s habitual chilly drizzle? – it turns out that the results will be nastier than anyone anticipates. As Prof Mary Gagen of Swansea University explains: “We can expect a lot of very, very wet summers and winters and the crop failures that accompany that will cause severe food shortages.”
There is a paradox not lost on Bullough that he is mourning the damage done to the landscape by humankind even as he is walking on a road made by those first disrupters, the Romans. “Sarn Helen was extractive, let’s just say it,” he admits. It was built to carry away the natural resources of Cambria – the minerals particularly, especially the gold – and bear them back to the imperial city. While it would be nice to think that Wales’s first road was commissioned by an empress-saint to bring the edges of her country together, the fact remains that it was built by colonialists to carry off the swag.
The long-term impact of this type of environmental ransacking can be seen in the Covid masks and social distancing that Bullough encounters every time he drops down into a valley to buy chocolate bars from service stations in his late-learned and stumbling Welsh. Gagen lays out the process by which zoonosis occurs: decimation of natural habitats brings animals into closer proximity with humans, which in turn makes it easier for viruses to jump between species.
Bullough’s road trip ends unexpectedly, far away from Wales, in the cells of Charing Cross police station. He explains that in September 2020 he was arrested and charged for refusing to move on from Parliament Square during the Extinction Rebellion protest. As a middle-aged novelist with two children, who has never been in trouble with the law, he feels a kind of horror at what he has done. For years he thought that his words were enough – and his words, in this book at least, are indeed beautiful and always to the point. So why go looking for extra complication, he asks himself – before realising that complication is already here, encircling us while we, like the legionaries, march heedlessly on.
• Sarn Helen: A Journey Through Wales, Past, Present and Future by Tom Bullough is published by Granta (£16.99). To support the Guardian and the Observer buy a copy at guardianbookshop.com. Delivery charges may apply.