AN 18th century barn at Malham Tarn is a casualty of climate change and has collapsed as a result of soil shrinkage, the National Trust has said.

The Trust has created a mapping tool to outline the threats and ‘worst case’ climate impacts on heritage and landscapes across the country by drawing up a “game changer” climate change map plotting areas where they may be possible threats.

The mapping tool outlines threats posed by climate impacts including extreme heat and humidity, landslides, high winds, and floods, and how they could change by 2060, to help the charity intervene to protect its sites.

The map is based on a “worst-case scenario” of a failure to drive down carbon emissions over the coming decades, but is intended to be a flagging tool to highlight potential hazards in the area of a heritage or countryside site.

One of the examples the Trust has highlighted is the 18th century barn.

The Trust said the ‘otherwise sound’ barn collapsed due to soil shrinkage, but teams can now intervene with moves such as tree planting and using certain plants to manage the water table.

National Trust director for land and nature Harry Bowell said: “This map is a game changer in how we face the threat climate change poses to the places we care for.

“While the data draws on a worst-case scenario, the map paints a stark picture of what we have to prepare for.

“But by acting now, and working with nature, we can adapt to many of these risks.”

The Trust reveals that, without action on emissions, the number of its sites in areas at the highest threat level from climate impacts could more than treble from 3,371 (five per cent) to 11,462 (17 per cent) over the next 40 years.

And the number of sites at high or medium risk of climate-related hazards could increase from 20,457, or 30 per cent of sites, to 47,888, or 71 per cent by 2060.

Identifying areas at risk will help the National Trust pinpoint locations that could need interventions such as planting trees or restoring peat bogs to hold or slow the flow of water to prevent flooding, or more shade to protect areas at risk of high temperatures.

The map will ensure that, under a commitment to plant or establish 20 million trees to tackle climate change, trees go in the places they are needed most, the charity said.

The map plots the impacts of extreme heat and humidity, landslides, coastal erosion, shrinking and shifting ground due to wet and dry conditions known as “soil heave”, and high winds, in 2020 and 2060.

It uses data from a number of sources and plots them in 5km hexagonal grids across England, Wales and Northern Ireland. The Trust is also sharing available data on flooding with staff on properties prone to flooding and action that can be taken.