Risks Imposed by Climate Change on the Cultural Heritage of Lesotho

Lesotho's rich cultural heritage is under threat from the effects of climate change.

International Encyclopedia of Human Geography (Second Edition), 2020 describes cultural heritage as an expression of the ways of living developed by a community and passed on from generation to generation, including customs, practices, places, objects, artistic expressions, and values. Climate change refers to global or regional long-term changes in weather patterns. Climate change, if we do not push much harder to curb it, will affect Lesotho's most precious cultural heritage assets.

 Climate change is undeniably damaging a lot of things around us, but a lot of people never realized the potential threat it is posing to culture. In Lesotho, climate change is posing a very serious threat to the built heritage. The built heritage, including monuments and historic buildings, is at risk from different extreme weather events. The collections and interiors of these buildings are also threatened by climate change. For example, Thaba-Bosiu National Monument is at risk of landslides, erosion, and rockfalls and the Liphofung Historical Site is at risk of rockfalls and its interior and collections are at risk of mold.

This article will explore the specific threats by climate change on the cultural heritage of Lesotho, and how these threats can be mitigated. Now, let us inquire into the threats of climate change on built heritage. We will look at the threats of climate change on the outdoor heritage and the indoor heritage which consists of interiors and collections. There is a weathering process called Freeze-thaw. Freeze-thaw is a process whereby erosion happens in cold areas where ice forms.

 Due to climate change, Lesotho experiences high rainfalls in summer and it becomes very cold in winter. There are cracks in rocks. When it rains, the rainwater enters the rock through these cracks. When temperatures drop, the water in the cracks freezes. As the ice expands, it pushes the crack apart, making it larger. When it is hot, the water in these cracks melts and contracts. This process of heating and freezing the rocks repeatedly will make the rock fall apart.

Simply explained, warmer temperatures could increase the frequency of freeze–thaw cycles, causing structural damage to many cultural masonry buildings, especially Thaba-Bosiu National Monument. The other threat of climate change to the outdoor heritage in Lesotho is corrosion. Collins dictionary describes corrosion as the process in which a metal is gradually destroyed by an electrochemical process.

Due to climate change, there are changes in temperature and humidity. These changes when merged with air pollution can lead to the corrosion of metals and masonry buildings. A typical example can be of the heritage buildings on the plateau of Thaba-Bosiu whose roofing has rusted and is continuing to rust. Material erosion is another threat to the outdoor heritage of Lesotho.

 Material erosion is caused by wind and wind-driven rain. They (wind and wind-driven rain) cause material erosion in a few ways:

• Wind can blow away small particles of soil or sand, causing the surfaces of objects to become pitted or worn.
• Wind can also carry water droplets that can cause corrosion or staining on objects.

 Finally, wind can cause objects to vibrate or shake, which can cause stress fractures and other damage. Wind-driven rain destroys materials and damages the surfaces of historical buildings and monuments and increases the risk of water penetration into porous materials. Material erosion is a real threat to historical buildings, monuments, archeological sites, and rock art present in the cultural heritage of Lesotho. For example, Morija Museum & Archives, Kome caves, Liphofung caves, etc.

Now, let us navigate through threats of climate change on the outdoor heritage of Lesotho. Due to climate change, Lesotho experiences high rainfalls in summer and it becomes very cold in winter. These high rainfalls damage the hygroscopic wooden materials and the historic masonry buildings. High rainfalls and high indoor temperatures also increase the structural damage to historic masonry buildings. Almost all the cultural buildings in Lesotho are masonry built. These buildings are mostly at risk in Summer, as already stated. Paint on these buildings is also at risk of decay, especially on wooden art objects.

Climate change also poses the threat of biological degradation to the indoor cultural heritage of Lesotho. In winter it gets very cold and this increases mold growth in the collections and archives in historical buildings. Morija Museum & Archives is at risk of an increase in the biodegradation of organic objects.

There are a few different ways that we can mitigate the impact of climate change on cultural heritage. One is adaptation, which involves making changes to buildings and sites to help them withstand the effects of climate change. Another way is through mitigation, which involves reducing our carbon emissions to slow down climate change. We can also work on preserving digital records of our cultural heritage so that even if the physical objects are damaged, we will still have a record of them.

For cultural heritage in elevated locations, like Thaba-Bosiu National Monument, we can monitor the site for signs of instability, so that we can quickly take action if there is a risk of damage. Another way is to reinforce the site with structural supports, like buttresses or piles. 

Most importantly, we need to educate the public about the impact of climate change on our cultural heritage. If people are aware of the risks, they can help to support efforts to protect these sites. For example, people can visit historical sites and support local cultural businesses, which helps to fund conservation efforts. They can also advocate for policies that protect cultural heritage.