Drying Peatland Endangers Hadrian’s Wall and Other Archaeology Sites
In the year 122 AD, workers laid the first stones on Hadrian’s Wall, the imposing Roman-era defensive fortification that would run horizontally across northern England from sea to sea. When completed the wall was 73 miles (117.5 kilometers) long and formed a uniform impenetrable barrier that separated Roman Britannia from the unconquered lands of Caledonia (modern-day Scotland). This is the 1,900-year anniversary of the beginning of this ambitious construction project, which stands today as one England´s most well-known and frequently visited archaeological treasures. Unfortunately, the peatlands around these ancient sites are drying up and this is causing considerable concern among archaeologists.
Celebrations to acknowledge the 1900th anniversary of Hadrian’s Wall are scheduled to begin this week, and scholars are taking advantage of the public’s renewed interest in ancient history to sound the alarm about the peatlands climate change problem that threatens not only Hadrian’s Wall, but many other critically important archaeological sites in the United Kingdom.
The problem in question is climate change, an existential threat to humanity and the natural environment that could dramatically affect everyone on the planet. According to the latest estimates, as many as 22,500 archaeological sites in the United Kingdom, including almost all peatland sites, may be at risk from climate change, should the heating and drying out of the climate continue at the present rate.
Peatland in Lewis, Scotland with usable peat pieces on the right. (Wojsyl / CC BY-SA 3.0 )
Why Are The UK’s Peatlands in Peril?
The greatest concern currently is the fate of country’s vast expanses of peatland. This waterlogged soil type covers about 10 percent of the land area in the UK, and their unique characteristics make them an ideal location for archaeologists searching for previously undiscovered finds. Artifacts are well-preserved and protected from erosive elements in peatlands, and past excavations have produced a number of exciting discoveries hidden inside the UK’s many peat bogs, mires, and fens.
The problem for peatlands is that the heating of the climate plus affiliated droughts is starting to dry them out at an alarming pace.
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In their natural state, peatlands are highly anaerobic, which means they contain miniscule quantities of oxygen compared to normal soil. As a result, organic materials (i.e., wood, textiles, leather, and even human flesh) do not rot when they are encased in peat. Assuming no contamination takes place, artifacts could be preserved for several thousand years without decaying much at all.
When peatlands start drying out, however, everything changes. Drying soil will become increasingly saturated with oxygen over time, which can significantly accelerate the process of decay of organic materials trapped inside the soil. The ultimate destruction of ancient organic remains then becomes inevitable if nothing is done to rescue them.
Archaeologists aware of the problem might have some time to get inside a drying peat bog or fen to extract artifacts before they disintegrate completely. But without knowing the best places to look, it would be next to impossible to stay ahead of climate change-induced destruction of sensitive organic artifacts.
The world’s oldest boxing gloves were recovered during excavations in the Vindolanda peatland soil, next to Hadrian’s Wall. ( Vindolanda Trust)
A Rich History at Risk: Archaeologists Sound the Warning
The BBC spoke with several archaeologists and other scholars who are aware of the problem.
One of these experts, Teesside University archaeologist Dr. Gillian Taylor, told them that climate change would be “catastrophic” for archaeology and paleoanthropology, because of the immense losses that would result from the drying up of peatlands.
“We will lose part of our heritage if we don’t look at what’s occurring now,” she warned.
Unfortunately, the drying of England´s peatland soil may already be affecting ongoing archaeological work along the length of Hadrian’s Wall .
Dr. Andrew Birley, an archaeologist leading the excavation of a Hadrian’s Wall fort in Carvoran, Northumberland known as Magnae, told the BBC that damage due to soil degradation is already in evidence at his site. This puts what he termed “an historical time capsule” at great risk, since digging has only just begun at this sprawling 2,000 complex and sprawling ruins.
“Pretty much everything the Romans used here for 300 or 400 years could have been preserved in more or less the same state it was thrown away, which is an incredible opportunity,” Dr. Birley said, lamenting the changes that are underway. “If we lose places like this, we lose that direct connection to the people who lived on this island 2,000 years ago. We lose the chance to learn as much as we can about them, and we lose part of our own heritage and part of our own history.”
Another site along Hadrian’s Wall that could be at risk because of climate change is Vindolanda, another Northumberland Roman fort that was occupied by several generations of Roman defenders from 85 to 370 AD.
More Roman footwear, including a broad variety of boots and shoes, has been found here than at any other site anywhere in the world. The world’s oldest boxing gloves have also been recovered during excavations in the Vindolanda peatland soil, along with the world’s oldest handwritten message composed by a woman. The latter contains an invitation to a birthday party and was sent by the wife of the commanding officer of a nearby fort to her friend who was residing at Vindolanda.
Each of the aforementioned artifacts is comprised of organic materials. If the drying of the soil caused by climate change continues, they are exactly the type of artifacts that will disintegrate and disappear in huge quantities.
Lindow Man was found in a peat bog in 1984 and was amazingly preserved due to the lack of oxygen in the bog. (© The Trustees of the British Museum / CC BY-SA 4.0 )
There May Be No More Lindow Men Because of Climate Change
England’s most famous peatland archaeological discovery was the Lindow Man . This eerily well-preserved body was unearthed from a peat bog called Lindow Moss in Cheshire, Northwest England by a commercial peat cutter in 1984. The Lindow Man’s body was eventually radiocarbon dated to the first century AD, although no one would have guessed that based on his appearance. Despite the passage of nearly 2,000 years’ time, many of the features of the Lindow Man were still recognizable, which was an impressive testament to the incredible preservative powers of peatland.
Discoveries like this may become a thing of the past, if the worst fears about the impact of climate change on England’s peat bogs, mires, and fens prove to be justified. Archaeologists who plan to excavate these prime locations may be in a race against time, as they try to discover and recover as many valuable at-risk artifacts as they can before it is too late.
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"Peatlands represent such a small part of the ecology of Britain, but they have massive potential to tell us about our past," said Dr. Rosie Everett, a biologist from Northumbria University who has been studying the effect of climate change on peatland archaeology. “The loss of peatlands would have big implications for the understanding of the country's history, but also for our climatic history and our environmental history.”
Sadly, there are limits on the funds available funds to sponsor excavations in threatened areas. This means many amazing treasures may be lost, regardless of how quickly concerned archaeologists are able to spring into action.
Top image: Pictured here is another example of Roman shoes found at Vindolanda, alongside Hadrian's Wall in peatland. Source: Vindolanda Trust
By Nathan Falde