Preserving Built and Natural Heritage

Meredith Wiggins: Well, first and foremost it’s important to recognise that so much heritage is natural, and so much of nature is heritage. Flying over the UK you can see medieval villages, Iron Age field systems, prehistoric trackways. These things are both natural and cultural. To think of them separately would be to miss the whole picture.

There are many ways that heritage is affected. For instance, coastal sites across the world are being directly affected by environmental processes: flooding, erosion, storms, warming, acidification, etc. These damage above-ground heritage and underground deposits.

The indirect ways that heritage is being affected are more complicated. One example: The UK has the oldest building stock in Europe, and over the last 30 years or so there has been a big push by government to improve what were seen as ‘leaky’ historic buildings. To that end double-glazing and loft insulation were installed in many properties. However, sealing houses allows moisture to build up, which isn’t great for the building and hinders their ability to function.

Hannah Fluck: It is also worth remembering that cultural heritage includes both the tangible historic environment and intangible heritage – our way of being in the world. Climate change affects all of these aspects of heritage. In terms of direct impacts we tend to think of climate change as a risk multiplier. Most of the physical processes that we associate with climate change have always occurred but what is different is the severity and frequency of these occurrences.

Increases in rainfall and rain intensity mean gutters and downpipes on many buildings are unable to cope in the heaviest downpours that can lead to damp and all sorts of problems associated with water ingress. Increased humidity, particularly accompanied by increasing temperatures, can lead to plant growth that can harm our monuments. The surface of masonry also decays more rapidly in warm, wet conditions. And although the number of ‘frost days’ may be going down as temperatures rise, they are occurring more sporadically, so the freeze-thaw cycle may increase.

With increasing droughts and extremes of wet and dry, archaeological deposits will be affected and we will lose sites and the information within them, often before we even know of their existence. And as our oceans warm the distribution of shipworm is changing. This is a mollusc that burrows into the wood of shipwrecks and can cause real harm to underwater archaeological sites.

Fluck: Historic England has undertaken research to explore how and when the historic environment can be described in terms of the ‘ecosystem services’ it provides. Many heritage assets such as field boundaries, traditional walls, water meadows, do provide real environmental benefits as well as heritage value. A good example is the way in which our historic parks and gardens help alleviate ‘heat island effect’ in our urban areas.

There are a number of habitats that are particularly valuable to our wildlife and are inextricably linked to our historic environment. One is unimproved chalk grassland. In the south of England most of the best examples are on archaeological sites such as Iron Age hill forts like Silbury Hill – both a Site of Special Scientific Interest (SSSI) and a Scheduled Monument. Another example is wood pasture and parkland that are extremely valuable for wildlife and are historic landscapes that result from human activity.

Often even natural-looking watercourses have been considerably shaped by human activity. The historic environment can help us to understand why certain areas flood, as well as provide the evidence for the impact that human activity in the past has had upon the way water behaves. This can support better decision making about the future management of catchments.

Wiggins: We have experts coming at the issue from all angles; planning, conservation, policy, research, analysis and advice. The #climateheritage international community was really forged in 2015 at the Pocantico Summit on Climate Change and Heritage outside New York. Out of it came the Pocantico Call to Action on Climate Change and Heritage, which enshrines our sector’s views on climate and culture in a single document. More colleagues are joining us every day.

Fluck: Following on from Pocantico we have been involved with the establishment of the international Climate Heritage Network (in November 2019) to raise awareness and to recognise the role we, as a sector, can play in reducing greenhouse gas emissions, and in supporting adaptation to future climate.

Wiggins: There are certainly excellent technical projects that involve the recording of sites and the identification of new ones (eg CHERISH on coastal heritage), and amazing projects linking northern countries (ADAPT NORTHERN HERITAGE). But where the UK really leads the way is in the application of community-based approaches. There are places all over the world that are facing the inevitable loss of their heritage but, as heritage professionals, we have a responsibility not to ‘save’ things, rather to empower communities to make informed decisions about the places that they value. These are difficult conversations.

Last year we commissioned a project to create a coastal risk map of England that would help local government to prioritise action. This was just a pilot, but the results were promising, and we’ll be expanding its scope to look at different types of environmental and climate risk.

Fluck: For me there are two key lessons: Firstly people respond much better to positive solutions rather than more doom and gloom. Our research shows that there are real gains to be made by learning from the past to help us adapt to low-carbon, sustainable futures. Many of our traditional building techniques and materials (such as lime, earth, wood, thatch) are not only inherently low-carbon but also far more resilient to the impacts of climate change such as flooding and overheating. The extent to which our traditional buildings recover well from flooding really surprised me. There are also real opportunities for learning from vernacular buildings in other places where historical conditions may have been more similar to our future climate.

Secondly it is important to find common language. For instance our work on ‘natural capital’ has real potential to change the way in which we express the value of the historic environment not just in cultural terms but also as part of the fabric of our environment.

Wiggins: The idea of “safeguarding” is problematic when you’re talking about climate change because all heritage will be affected and needs to be factored in to planning. However, if you’re trying to look at the effects of climate change on specific sites, you really need to understand different types of local resilience too. That is why approaches like the World Heritage Climate Vulnerability Index (which takes community resilience into its calculations) are so important.

In the UK at least, much of our heritage is extremely resilient, and will hold up well in a changing climate. The adaptations we’ll need are societal, and are more about managing expectations. Heritage holds a place in our minds as ‘always being there’ and people, faced with changes to landscapes they have known their whole lives, the loss of monuments they have seen every day, may feel frightened.

Heritage professionals across the world are well-placed to help with this. We know that things have changed in the past, and we have evidence of how communities have succeeded (or failed) before. We know the materials, practices and ideas that are both durable and flexible.

Fluck: But is also worth noting that people view change differently. We were fortunate enough to have anthropologist Dr Vera Da Silva Sinha come and undertake some ethnographic research for us in an area of England affected by considerable coastal change. What was really striking was the number of people who said that what they valued about this place was the sense of history, and continuity and the way in which it had remained unchanged for so many years – and this is a part of the coast where the cliffs are collapsing and many meters are being lost each year! We need to be careful about not making assumptions about whether people would define change in the same way we might.

Wiggins: In the UK it’s estimated that 80% of the buildings that will exist in the year 2050 have already been built. It’s therefore critical that we leverage our existing building stock in the service of decarbonisation. Historic England is working on a comparative life-cycle analysis of adaptive reuse vs. demolition and rebuilding. This is in the context of the very tight timelines for carbon reduction (the UK has committed to Net Zero by 2050). We wanted to know how historic buildings stack up against new buildings when over half of a low-energy building’s environmental impact occurs before it is even occupied.

The UK holds between 9-15% of Europe’s peatland, which is the most important type of habitat for carbon sequestration, as well as holding a wealth of archaeological information. Also, hedgerows, which are a cultural feature, provide similar decarbonisation benefits to agroforestry while also improving farmland biodiversity and shelter for grazing livestock. I could go on, but you get the point!

Fluck: As well as the initiatives above and our next national cyclical reporting in 2021, we are also contributing to the third UK Climate Change Risk Assessment due for publication in 2022. We are drafting an environmental strategy that will look at how we can become much better at embedding consideration of climate change within our own decision-making including better mapping of climate hazards and understanding how those translate into risks.

Heritage on the Edge