[ti:Climate Change Threatens Scottish Historical Treasures] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]Historians are warning that some ancient British structures are being threatened by climate change. [00:10.56]One of the most affected places is around the Orkney Islands, which are off the northern coast of Scotland. [00:21.52]The area is home to more than 3,000 historical places. [00:27.52]But, the islands have been severely affected by rising sea levels, [00:32.84]heavy rainfall and severe weather events in recent years. [00:40.16]Evidence has been found around the Orkney Islands that humans lived there as far back as 8,500 years ago. [00:51.64]Some structures on the islands were built during the Iron Age, Viking rule and the Middle Ages. [01:01.80]Archaeology experts have estimated that about 1,000 historical sites are under threat. [01:10.84]One of those identified is the Iron Age building South Howe Broch on the island of Rousay. [01:20.48]Now, the sea has eaten away much of the site's western area. [01:26.24]The main wall has started falling into the sea. [01:30.29]Julie Gibson is with the University of the Highlands and Islands. [01:37.32]She told Reuters news agency that she fears the whole structure will one day completely disappear. [01:45.80]"Each year a little more falls as the sea batters it," Gibson said. [01:53.00]She said experts have discovered in recent years that all of the settlement archaeology in the area [02:00.60]is within 100 meters of the coast edge. [02:05.68]"So as the sea takes this heritage of ours away, it's taking all that we have," she said. [02:14.72]A few hundred meters away from South Howe Broch is Midhowe Broch. [02:20.96]This Iron Age building is still in good condition because it has been protected by a sea wall built in the 1930s. [02:31.27]But experts say even this site faces risks if climate conditions continue to worsen. [02:40.56]A climate risk report for the Orkney's historical sites was published in July [02:46.88]by the environmental group Historic Environment Scotland (HES). [02:55.24]The group described the possible effects of climate change on sites [03:00.42]as "extreme," with a "high" level of vulnerability. [03:07.08]HES reported that the average precipitation rate has risen 27 percent in Scotland since the early 1960s. [03:18.36]During the same period, winter precipitation has increased more than 70 percent [03:24.13]in parts of northern Scotland, it found. [03:29.16]Wetter weather means buildings stay wet longer. [03:33.52]This increases the chances of water entering deeply into structures and causing damage. [03:42.04]The precipitation also can harm metal parts of buildings and lead to the ground becoming unstable. [03:50.96]Over time, such damage can cause structural collapse. [03:57.08]Climate records show that since 1970, some Orkney beaches have narrowed by an average of 40 centimeters a year. [04:07.68]That compares to a yearly average loss of 20 centimeters between 1890 and 1970. [04:17.60]In addition, increasing and more intense storms are threatening the Orkney's historical sites, HES reports. [04:28.64]One example is Skara Brae, one of Orkney's most famous places. [04:35.24]Back when people lived in the area, it was about one kilometer from the sea. [04:41.03]Today it is just a few meters away from the North Atlantic Ocean. [04:47.72]I'm Bryan Lynn. [04:49.73]更多听力请访问51VOA.COM