In other words, ice-skating is as Viennese as sausages and symphonies. So the idea of a permanent rink, housed inside a high-rise complex to minimize obstruction to pedestrians, would not have been expected to invite controversy. But one important stakeholder strenuously objected: the UNESCO World Heritage Committee, which decreed that the new complex would undermine central Vienna’s “outstanding universal value. Vienna’s historic city center has been a UNESCO World Heritage site since 2001, one of the organization’s 1,154 unique landmarks around the globe deemed worthy of protection. Since announcing its objection to the high-rise rink in 2017, the World Heritage committee has kept Vienna on its “in danger” list—joining 50 other embattled sites, from the ancient villages of northern Syria to Everglades National Park in Florida. If the city fails to satisfactorily address the committee’s concerns, it risks being permanently “de-listed” as a UNESCO landmark.

(Here’s how World Heritage status helps destinations around the world.)

Protecting an anything-but-static urban area like Vienna’s historic city center is an inherently fraught proposition. It’s one of several challenges that UNESCO’s program has struggled to overcome since its inception in 1972. Foremost among these involves its central charter: to promote cultural awareness by drawing attention to emblematic monuments, landscapes, and habitats around the world.

Challenges to protecting World Heritage sites

The World Heritage designation has unquestionably succeeded in attracting visitors to isolated, often economically disadvantaged places. Its track record has been mixed, however, when it comes to preventing the flow of tourists from becoming a deluge. For example, the once somnolent village of Hoi An, on Vietnam’s central coast, now faces a crush of visitors that its narrow streets cannot accommodate.

Some locales have succeeded in managing overtourism on their own, like Dubrovnik, Croatia, which, under pressure from UNESCO, capped the number of visitors in its historic center.

Then there are Cambodia’s 12th-century temples at Angkor Wat, at one time accessible only to priests. The temples were attracting 22,000 annual visitors when they were inscribed as a World Heritage site in 1992. Today, that number is five million and is expected to double by 2025.

(Angkor Wat, the world’s biggest religious complex, is sacred to two faiths.)

UNESCO has preferred to frame its work at Angkor as “a model for the management of a huge site that attracts millions of visitors and sustains a large local population.” But as the organization has also conceded, mass tourism has threatened the region’s water table, which in turn has imperiled the stability of the temples themselves.

Insulating World Heritage sites from malevolent actors has long been beyond UNESCO’s capabilities. The deliberate targeting of a country’s cultural treasures as a show of military belligerence has been all too common—from Aleppo, Syria, to Sana’a, Yemen. Famously and tragically, it could not halt the Taliban’s destruction of the towering Bamiyan Buddhas in Afghanistan in 2001.

Throughout its half-century history, the World Heritage program has de-listed only three sites. In each case—Oman’s desert ecosystem of the Arabian Oryx Sanctuary; Dresden, Germany’s Elbe Valley; and, last year, the historic center and docklands of Liverpool, England—it was after governments persisted with development projects at the sites over the organization’s repeated objections.

Still, UNESCO’s influence can extend only so far. In Laos, for example, the government has proceeded with plans to construct a dam on the Mekong River near the ancient capital of Louangphabang, despite UNESCO’s insistence that a heritage impact assessment takes place beforehand.

Climate change threatening World Heritage sites

Of late, UNESCO has had to confront a newer enemy: climate change. In 2007, it published a paper written by scientists who alerted the organization to growing threats in 26 different World Heritage sites. These included glaciers and biodiversity hotspots, but also archaeological landmarks such as the sprawling pre-Hispanic earthen city at Chan Chan, Peru, due to intense precipitation brought by El Niño.

On this front as well, the organization has limited tools at its disposal. An example is Australia’s legendary Great Barrier Reef, a World Heritage site since 1981. Last year, UNESCO threatened to place the vast coral ecosystem on the “in danger” list if the Australian government did not more adequately work to reduce its greenhouse gas emissions—the first time in its history that climate change factored into such a warning.

After intense lobbying from the Australians, the committee deferred its decision until late 2022. In March, UNESCO dispatched a monitoring team to the reef. Although the Australian government has reportedly pledged roughly $125 million to protect the reef, it remains to be seen whether Australia’s historical aversion to a responsible national climate policy will be reversed.

UNESCO has tended to have considerably more leverage in less wealthy countries, like Belize, where the world’s second biggest reef had languished on the World Heritage Committee’s “in danger” list since 2009 until this past June, when the committee applauded Belize for its “visionary” efforts to better manage its coastline.

(Once devastated, these Pacific reefs have seen an amazing rebirth.)

Perhaps the most famously at-risk World Heritage site is Venice, Italy. The lagoon city has been simultaneously beset by stupefying overtourism (25 million visitors in 2019) and increasingly severe flooding exacerbated by climate change. Yet UNESCO decided last year not to place Venice on its “danger” list—once again, an apparent victory for government lobbyists and a defeat for environmental groups, who argued that Italy’s new ban on large cruise ships did not go far enough to address the crisis.
Following UNESCO’s act of inaction, Venetian officials took matters into their own hands. Beginning in January, Venice will be the first city in the world to charge an entrance fee, in hopes that this will slow the daily avalanche of visitors. Will it work? If it does, UNESCO will have played a role—indistinct and inconclusive, but still important.

Flawed and at times powerless though it may be, the World Heritage program remains relevant, if only because of the principle it espouses.
That principle is as simple as it is inconvenient: the world’s diverse treasures require protection since they cannot protect themselves. So it matters to say, as UNESCO has, that an ice skating rink endangers Vienna’s historic center. If, at such moments, the World Heritage Committee exists only as a focal point where conscience is summoned, then the next 50 years may find it more important than ever.