Algumas das paisagens históricas mais apreciadas da Grã-Bretanha, como o Lake District, Snowdonia e as Ilhas Orkney correm o risco de serem severamente danificadas e alteradas para sempre pelos efeitos das mudanças climáticas, de acordo com um arqueólogo da Universidade de Sheffield.

Pesquisa de Isabel Cook, um Ph.D. estudante do Departamento de Arqueologia da Universidade, está aumentando as evidências de que as paisagens históricas em todo o Reino Unido já foram afetadas pelos impactos das mudanças climáticas, como a elevação do nível do mar, erosão costeira e inundações.

Entre as paisagens históricas afetadas está o Vale Dysynni, no País de Gales, que é o lar de vestígios militares que datam da Segunda Guerra Mundial. A pesquisa de Isabel descobriu que a área corre risco de aumento do nível do mar e inundações, com os restos sob grave ameaça de erosão.

Estudos anteriores mostraram que locais históricos, como os Forts of the Saxon Shore, uma coleção de fortalezas costeiras romanas que se estendem ao longo da costa sudeste da Inglaterra e incluem características do Castelo de Dover, Castelo Pevensey e Castelo Burgh, foram afetados em vários graus por processos costeiros, como erosão e deslizamentos de terra. Alguns dos fortes saxões da costa foram perdidos completamente devido à erosão, como aqueles em Walton Castle em Suffolk.

A pequena cidade de Dunwich, que era um grande centro de construção e comércio de navios medievais na costa de Suffolk no século 14, viu seu litoral recuar 600 metros - algo que destruiu completamente o patrimônio cultural e o caráter histórico da cidade. Dez igrejas e um convento foram perdidos lá até agora, com a erosão continuando a ameaçar o resto da área.

A pesquisa de Isabel revela como a perda vivida em Dunwich não se relaciona apenas ao desaparecimento de edifícios e locais isolados, mas também à perda do património da vila e do carácter histórico da paisagem urbana.

Com a ameaça ao Vale Dysynni, as perdas sofridas na costa sudeste e as notícias recentes de que a elevação dos mares e o aumento das chuvas estão ameaçando o status de patrimônio mundial das Ilhas Orkney, o arqueólogo da Universidade de Sheffield está pedindo mais ações para proteger as paisagens históricas do Reino Unido, que ela enfatiza são "museus vivos".

Isabel disse:"As paisagens são extremamente importantes para o património cultural, não apenas no Reino Unido, mas em todos os países do mundo. São espaços dinâmicos que guardam o património e a história da nação ao mesmo tempo que funcionam como atracções turísticas e apoiam as indústrias agrícolas. São locais com quem interagimos, e viver dentro, formando o contexto de nossas vidas, meios de subsistência e memórias. Isso torna as paisagens extremamente importantes para a identidade cultural, portanto, precisamos estar cientes da ameaça real que enfrentam devido aos efeitos da mudança climática.

“Já estão sendo tomadas medidas para tentar proteger importantes monumentos históricos, mas precisamos perceber que paisagens significativas também correm o risco de mudanças climáticas.

"Imagine um Reino Unido onde as ruas e calçadões históricos de cidades litorâneas vitorianas, como Brighton, Bournemouth e Aberystwyth ficam obscurecidos por duras defesas costeiras construídas para proteger casas e empresas da erosão, rising sea-levels and extreme flooding events. Imagine a UK where the ornamental gardens of historic estates, like Chatsworth in Derbyshire and Cragside in Northumberland, are blighted by new invasive species, pests, and diseases, and ravaged by drought. We need to ensure our grandchildren and their grandchildren can experience and learn from these places as we have done."

While heritage agencies are beginning to acknowledge and take steps towards addressing the threat posed by climate change to historic buildings, monuments and sites, research by the University of Sheffield archaeologist reveals how little is being done to protect the landscape itself.

English Heritage has published a risk assessment on the threat of coastal erosion to its estate and the Shifting Shores report looks at the potential impact of climate change on National Trust properties. Although these reports mention the landscape setting of heritage sites, Isabel's research highlights how they do not specifically mention the threat to the historic landscape.

Research by the Sheffield Ph.D. student also reveals how most previous academic studies into the impact of climate change on archaeological remains omit any mention of historic landscapes.

Em resposta, Isabel has developed a framework for including historic landscapes in climate change impact, adaptation and mitigation research. This includes assessing how vulnerable historic landscapes are to the effects of climate change.

The framework also establishes a sustainability assessment methodology for coastal and flood-risk management that includes historic landscapes as a consideration—something which could be used by policy-makers to include the historic character of the landscape in climate change adaptation decisions. This could change the way that coastal erosion and flood-risk management is carried out in the future, with more consideration of the historic landscape alongside environmental, social and economic factors.

The Sheffield Ph.D. student's research also highlights how changes in temperatures and rainfall caused by climate change are likely to affect the distribution and behavior of plants and animals on important historical landscapes. Examples include the expansion of insect species towards higher latitudes and increased over-winter survival, which poses a greater risk of insect attack or bioturbation on important archaeological landscapes and remains.

Changing climatic conditions may also lengthen crop growing seasons and force people to grow food in different places, such as areas of important historical and cultural interest. Por exemplo, arable crop farming may become an option in areas once only suitable for extensive sheep farming. As well as affecting local economies and traditional ways of life, this change could affect the visual character of historically important landscapes, according to the study.

Historic woodland, parks and gardens, which characterize many historic landscapes, are also likely to be affected by changing temperatures and invasive species. This may affect the plants that can be grown in parks and gardens, and alter the ecosystems structure of ancient woodlands.

Adicionalmente, the University of Sheffield study highlights how the impact of climate change on historic landscapes is not limited to direct impacts—there may be impacts caused by the mitigation and adaptive approaches that are taken in response to climate change. Por exemplo, the construction of coastal defenses in response to rising sea levels could result in a coastal squeeze, causing the loss of saltmarsh and beach.

Coastal defenses can also significantly alter the character of the coastline, affecting visual amenity. The Sheffield archaeologist is calling for the impact of coastal defenses on the historic landscape as a whole to be considered, rather than just the impact on individual archaeological sites.

Isabel added:"A great wealth of archaeological material can be found on the British coastline and is now vulnerable to changing coastal processes that are being triggered by climate change.

"We've already seen coastal erosion and landslides—which are projected to worsen due to sea-level rise and increasing storminess—destroy many historic and prehistoric coastal fortifications and settlements on the south east coast of England. The loss of these features threatens the historic character of these coastal landscapes, be it a military and defensive landscape, a religious and early Christian landscape, or a landscape characterized by post-medieval trade and industry. We need to ensure that the historic landscape is factored into all climate change impact and adaptation research and management in the UK, at all stages of policy development and planning, rather than being considered only by heritage agencies.

"The framework developed through my research provides a simple method for establishing the different ways in which the character of each historic landscape is vulnerable to climate change. It also gives planners and policy-makers a useful tool for assessing the various ways in which different coastal and flood-risk management approaches will impact the historic landscape."