Rome – For centuries, Europe’s monuments have withstood earthquakes, fire and plundering. Now cultural treasures from the Colosseum to Westminster Abbey could face new threats from climate change, a study says.
Increased rain in northern Europe could wash away layer after layer of ancient stone, while rising heat in southern and central Europe could lead monuments to crack and disintegrate, according to the European Union-funded study.
Experts have long warned that a rise in sea levels attributed to global warming threatens low-lying areas, including treasures like Venice or sites in flood-prone regions.
But the three-year study didn’t look only at the catastrophic impact of storm surges, landslides and floods. It also took into account the slow erosion that Europe’s cultural heritage could suffer from climate change, said Cristina Sabbioni, the study’s coordinator.
“We needed to put this problem on the table, because so far it has been politically ignored,” said the physicist with Italy’s National Research Council.
Mapping vulnerability
Climatologists, chemists, geologists and biologists used projected climate data to predict how marble, limestone, wood and other materials commonly used in ancient buildings would fare until 2099, Sabbioni said.
Researchers produced a “Vulnerability Atlas” of Europe, with maps that indicate which areas will suffer an increase or decrease in risk factors, such as damage caused by salt crystals and corrosion of medieval stained-glass windows.
According to the study, lower humidity during the summer in Britain, France, northern Spain and central Europe will increase the amount of salt deposited on monuments.
This is especially dangerous for the region’s Gothic cathedrals, whose elaborate carvings are made of soft, porous stone that absorbs sea salt from the air. Once the water evaporates, the salt crystallizes and puts pressure on the surrounding stone, Sabbioni said.
“If the salt is deposited on the surface, the damage is aesthetic, and this is a dramatic problem for frescoes,” she said. “But if it is absorbed, we have internal breakup of the material.”
Monuments built of marble and limestone, such as the Colosseum in Rome and the Parthenon in Athens, will also suffer because of increased temperature fluctuations, which cause such materials to expand and contract, causing fractures and breakage. Central Europe, southern Spain and Greece will be the areas most affected because of the drier climate and rising temperatures, the study says.
Even more recent monuments like the Eiffel Tower, completed in 1889, could face trouble as warm weather and pollution increases corrosion of metals in northern Europe.
Positive effects also seen
Not all the study’s predictions are negative. Glass corrosion is expected to decrease across Europe, and reduced moisture will help bricks in historic buildings stay dry.
But Sabbioni warned the overall effects could be even worse than predicted because the climate model used for the study was a “moderately optimistic” chosen from among those used by the U.N.- sponsored Intergovernmental Panel on Climate Change.
“Priorities will have to be established,” Sabbioni said. “We cannot hope that everything will last forever.”
