The Nahrein Network


Climate Change Threatens Archaeology

13 June 2022

The Great Mosque, 1907, Djenne / DeAgostini / Getty Images

BY Melissa Gronlund

At Bagerhat in southern Bangladesh, a city of 360 mosques from the 15th century, salt water from the encroaching Indian Ocean is damaging the foundations. In Yemen, torrential rains are decimating the improbable mud-brick high-rises of Shibam’s 16th-century architecture, newly exposed owing to strikes from the conflict there. In Iraq, the country’s southern marshes are drying up, causing the Indigenous Bedouins to flee for cities, leading to drastic loss of intangible heritage.

The effects of climate change on cultural heritage vary extensively but are inevitably complex. It acts like a cancer from within, whose steady growth is as difficult to track as it is to solve.

“The effects of climate change cannot be seen from one day to the next,” says Ajmal Maiwandi, director of the Aga Khan Trust for Culture in Afghanistan. “The physical damage to monuments caused by war and natural disaster can often be reversible. However, the gradual changes caused by alteration in the climate often remain unnoticed until it is too late to take action.”

And they are often multiple, with complications that compound one another.

Bagerhat, a UNESCO World Heritage-listed city, has become one of the most famous cases of climate-change-induced peril. Its mosques bear the distinctive domed architecture of the Indo-Islamic style, better known in its later, grander exemplars such as the Taj Mahal. Many of them are still used by members of the public — with the call to prayer given not via recorded messages but by muezzins who climb up the mosques’ squat, red-brick minarets. During cyclones, residents often shelter in the structures, whose solidity provides better protection than their homes.

In addition to the rising sea level, shrimp cultivation and the construction of dikes in the delta are moving salt water closer to the mainland and keeping it there for longer. The salinity creeps into the Bagerhat mosques’ brickwork, in a process called efflorescence, resulting in encrustation and discoloration. The waterlogged ground, meanwhile, threatens the buildings’ structural integrity.

Khandoker Mahfuz-ud-Darain, professor of architecture at nearby Khulna University, says that salination was always a threat, even when the structures were built, because of the tidal rhythms of a now-defunct river that once flowed through the site. Despite its being a rarely used technique in southern Bangladesh, the original architects surrounded the foundations with stone to shield the bricks from the sea water. And as a living city, Bagerhat benefits from having locals who look after the walls by, at least, wiping away the vegetation and dirt.

However, these fixes are proving insufficient against the growing scale of the challenges.

“Local people and the keepers of the mosque told me that 15 to 30 years [ago] there was less need for regular maintenance,” he says. “But now the fungus, efflorescence, encrustation and cracking are increasing rapidly. We have some very nominal budget by the government in this area, but even though the cost of maintenance is low, it is not enough. We need more budget to cover more activities.”

Ongoing local maintenance is a similar bulwark against climate change for mud-brick mosques in places such as Mali and Niger. The Great Mosque of Djenné hosts an annual festival of “crépissage” (plastering), in which the entire Malian city works to replaster the mosque before the annual rainy season begins. In a coordinated effort, teams prepare the mud, transferring it into wicker baskets and giving them to young men who climb up the buildings’ jutting spokes and apply the mixture to the facade. But crépissage cannot keep up with the new pace of rains. Agadez has been a UNESCO World Heritage Site since 2013, with a great mosque and decorated earthen-architecture houses that were built along the caravan routes of Niger in the 15th century. After a series of flash floods in the past few years, local bodies applied to the Swiss cultural agency ALIPH for emergency funding.

“We are using ancient methods,” says Mohammed Alhassane, whose agency, Imane Atarikh, looks after Agadez. He explains that these local techniques of mixing clay and animal dung have proved more effective in safeguarding the structures than ideas developed elsewhere.

But Agadez, like most sites where cultural heritage is under threat, is also vulnerable in terms of the economy and security. One of the cruelest injustices of climate change is the overwhelming effect it has on countries that have contributed the least to carbon emissions. In the realm of cultural heritage, architects and archaeologists are discovering that Indigenous knowledge provides one of the best ways to protect sites against climate change — but it is precisely this knowledge that is being lost amid a wider global displacement in rural communities.

In Agadez, employment is harder to come by, tourism has stalled and Nigerians are emigrating — taking with them the local know-how that would help maintain the Agadez Grand Mosque and its surrounding structures.

“Climate change is a multiplier,” says Andrea Balbo, an archaeologist who leads on the subject at ALIPH. “We’ve been trying to cluster three ways in which climate change, conflict and heritage interact. But these are complex interactions in the sense that it’s not an addition — not like one plus one is two. It’s more like one and one creates 5, 10 or 15.”

Effects traceable to climate change—such as drought and crop failure—fuel conflict, which then destroys or limits access to vulnerable sites of cultural heritage. According to the study “When Rain Turns to Dust,” produced by the International Committee of the Red Cross in 2020, out of the top 20 countries affected by conflict, 12 were also among the most exposed to climate change.

Once the sites are damaged, Balbo adds, some of the meteorological effects that climate change has contributed to, such as torrential rains, then further exacerbate the problems. Shibam’s mud-brick walls, exposed during bombings in Yemen, drip away into gushing streams once their outer layer has been damaged. Strong winds across central Iraq, which scientists attribute to the more extreme weather patterns of climate change, are eroding many of the exposed or hilltop sites in the country that remain difficult to reach for archaeologists.

In the Middle East, North Africa and South Asia, most research focuses not on archaeological sites per se but on the more complex ways that climate change threatens Indigenous communities, intangible heritage and biodiversity. This broad purview comes at a time when understanding of cultural heritage has itself undergone a major shift. For most of the 20th century, cultural patrimony denoted monuments, architecture and tangible artifacts — the temples and statuary that furnished stops on tourist itineraries and the contents of museums in the West.

In the early part of this century, the idea of intangible heritage emerged, covering rituals and practices that are unique to cultures, such as forms of dancing, singing and handicrafts. Now, a third shift is underway that is linking natural and cultural heritage. Heritage experts are thinking not just about depictions like the lamassu (a deity with a human head and animal features) of Nineveh but also the fertile lands around Mosul, as well as how the two combine to create the area’s culture.

In southern Iraq, for example, climate change has exacerbated the already huge losses of the Indigenous marsh people that occurred after the marshes were drained by Saddam Hussein.

“Their traditions were undocumented, so what we Iraqis have lost is a disaster,” says Jaafar Jotheri, a professor at Al-Qadisiyah University and a co-director of the Nahrein Network, a group of archaeologists focused on Iraq that is based at University College London. “We had 300,000 Bedouins before 2003. And now we have around 3,000 or less living in the desert. In 15 years we lost 300,000 people, with their culture, with their community, with their handicrafts. Why? Because of climate change: no rain, high temperatures, no more water in their springs.”

Jotheri estimates that within 10 years, the marsh people and their traditions will have completely disappeared as they emigrate to urban areas and assimilate into mainstream Iraqi culture. He and other members of the Nahrein Network are conserving what practices they can, but he acknowledges it is a race against time.

In Kabul, a key area under threat is the expansive Bagh-e Babur, the Mughal gardens laid out by the ruler Babur in 1504 and 1505. Such gardens are one of the most incredible and long-lasting legacies of the Mughal era. Built across the empire in cities such as Delhi, Agra, Lahore and Srinagar, they transpose the era’s architectural taste for symmetry and geometric rigor into landscaped form.

The Bagh-e Babur offer a prime example of a “chahārbāgh,” a four-quartered rectangular garden that is based on the four gardens of paradise in Islamic tradition. They were added to and maintained throughout Mughal rule in Afghanistan but largely despoiled for firewood over the course of the country’s conflicts in the 20th century. The Aga Khan Trust for Culture began restoring them in 2003.

But now they are again vulnerable — and not because of the return of the Taliban, who have in fact recently submitted a dossier to have the garden registered as a UNESCO World Heritage Site. Rather, decreased snowfall in the mountains and the extraction of water from deep wells by a growing urban population has lowered the water table in the Afghan capital. Maiwandi estimates that in the past 15 years, the water table level in Kabul has dropped, from 7 to 10 feet underground to some 130 to 200 feet below the surface.

The global temperature rise has also meant the introduction of new pests and diseases.

“The increase in new types of resilient diseases affecting the horticulture in the garden is a recent phenomenon — and the maintenance teams are not prepared to address the growing scale of the challenge,” Maiwandi says. “We are finding it more difficult to deal with them as traditional knowledge in treating these afflictions is not effective, and we are having a much higher rate of loss in the trees and plants.”

While monuments and artifacts can be conserved or reconstructed, nothing can be done to conserve the living species of the gardens once the ecology around them changes. As for climate change more broadly, there is both a surge of action and a general feeling of despondency over the chances of success.

Cultural heritage agencies are scrambling to reach out to scientists. The International Council on Museums and Sites (ICOMOS) released a widely read report on climate change and cultural heritage in 2019 (the rather poetically titled “Future of Our Pasts”), and in December last year ICOMOS convened with UNESCO and the Intergovernmental Panel on Climate Change (IPCC), bringing together scientists and those working in the field of cultural protection for the first time. A key outcome of the proceedings was the introduction of culture as a vulnerable category into discussions at the most recent U.N. climate summit, COP26 in Glasgow.

Smaller agencies, too, are creating dedicated stands to combat the threat, even in countries such as Syria and Iraq, where conflict has so far been the undisputedly largest danger to cultural heritage. The new agency Safina Projects is working to conserve traditional Iraqi handicrafts that are being lost because of water scarcity, such as boat-building techniques. The Nahrein Network recently added climate change as a sixth key aim to its charter, which focuses on the sustainable development of Iraqi heritage — an attempt, Jotheri says, to make up for the fact that Iraq still lacks a governmental body that oversees the effect of climate change across various sectors.

Many of the techniques used to address conflict-induced loss are being repositioned for climate change, such as high-data mapping and 3D visualizations that will create records of the vulnerable buildings should they collapse. Iconem, the French photography agency that mapped Aleppo after its siege, has worked on the mosques of Agadez, and the mosque city of Bagerhat partnered with the American company CyArk, which created 3D visualizations of the buildings and documented the process of efflorescence for Google Arts & Culture.

But the complexity of the problem and the fact that many of the most at-risk sites are in poorer countries mean that cultural heritage landscapes vulnerable to climate change will likely fall into the rhythm of reliance on international donor support. As the fallout from the Taliban takeover of Afghanistan shows, this funding is heavily contingent on broader political objectives — Maiwandi says he now spends much of his time persuading donors to resume their support for the preservation of Afghanistan’s heritage irrespective of their political differences with the Taliban.

At the same time, it is important to underline another shift in the cultural heritage sector: toward local knowledge and communities, which had long been sidelined by foreign “experts.” And the resolve among these communities is stronger and longer lasting. Mahfuz-ud-Darain notes that for Bangladeshi people in Bagerhat, the complications from climate change are bigger than just the threat to cultural heritage — and their resolve surpasses the idea of just steady maintenance.

The Bangladeshi people “are actively fighting and adapting to the new harsh climate,” he says, citing floating platforms for houses and new fishing practices alongside the regular activity of wiping down the Bagerhat brickwork. “They do not give up. These are their homelands — their motherland.”

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