UNESCO World Heritage site is in acute danger

Three of the most important world heritage sites are facing collapse

The Great Barrier Reef - a unique World Heritage site in acute danger © Sarah Ackerman / CC-by-sa 2.0
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Researchers are sounding the alarm: Three of the most important UNESCO World Heritage Sites are on the brink of collapse. Without increased measures, the Barrier Reef ridge, the Amazon forest and the Doñana wetlands in southern Spain threaten to end. But that would have consequences for the entire humanity, as the scientists emphasize in the journal "Science". Because these ecosystems are of global importance - and must therefore be preserved.

There is a reason why UNESCO mentions a natural heritage as well as a World Heritage Site. Because there are ecosystems that are unique worldwide and irreplaceable for the entire world. This applies particularly to habitats that fulfill important functions far beyond the region. These include the Amazon rainforest - the planet's green lung - and the world's largest coral reef, the Great Barrier Reef off Australia. Even the lesser-known Doñana wetlands in Andalusia are one of these nationally important systems, because every year half a million European birds hibernate here.

It is five to twelve

But this world heritage is in acute danger, as emphasized by Marten Scheffer from Wageningen University and his colleagues. For in addition to global problems such as climate change and the associated marine acidification, these World Heritage sites also lack local protection and conservation measures. "Bad local management, however, makes an ecosystem less tolerant of climate change and reduces its capacity to function effectively, " warns Scheffer.

Deforestation and drought make the Amazon Rainforest increasingly vulnerable Daniel Nepstad

As the researchers show in their study, there is a wide range in which a ecosystem seems to buffer threats and stress without major consequences. But once this buffer is exhausted For example, because several stress factors come together, then the entire system can collapse very quickly. And, at least for the three World Heritage sites studied, it's literally five to twelve, the scientists warn. If not at least the local stress factors are reduced, then they are threatened with collapse.

No question of money

And that is not always a question of lack of money, as the example of the Great Barrier Reef shows on the contrary. "As a rich country, Australia has the ability and responsibility to better protect the reef, " said Scheffer. Instead, water pollution from coastal agriculture and the dredging of harbors is on the rise, and overfishing also threatens the rich biodiversity of the reef. display

And if that were not enough, Australia still plans to exploit new coal mines and mine coal mines. "In the last few decades, half of the coral cover has already disappeared, " said Scheffer and his colleagues. "And the prospects are dark and worsening." UNESCO has already declared that this world heritage is officially endangered if nothing is done here.

Irreversible loss

The Do ana wetlands in southern Spain have already been classified by UNESCO as very endangered. The overcrowding caused by the surrounding agriculture and urban sewers is now and again leading to poisonous algae blooms in the innumerable ponds and rivers of the area. Elsewhere, valuable water is pumped out to feed strawberry fields and tourist seaside resorts. "Little has been done to control these local stressors and that makes Do ana unnecessarily susceptible to climate change, " the researchers say.

Cormorants in Doñana Alexwing / CC-by-sa 3.0

"All three examples play a critical role in global biodiversity, " the scientists warn. "When these systems collapse, it means irreversible extinction of species." These ecosystems are valuable to the entire world, not just the countries in whose jurisdiction they are located, This is especially true for the "green lung" of the planet, the Amazon rainforest. With him, the climate change is already clearly noticeable.

"There is no excuse"

The researchers see action and action opportunities especially in the local area: "The locally necessary measures are known and not even particularly expensive, " said Scheffer. The problem is that while these ecosystems are global in importance, they are mostly in one or a few countries. And if they refuse to do something, not much happens.

Therefore, in order to provide better protection, researchers find that other countries need to put more pressure on, or help them, the "host countries" to ensure that these iconic ecosystems are protected for the benefit of all humanity. "There is really no excuse for these countries to let the protection of this area grind, " said Scheffer. (Science, 2015; doi: 10.1126 / science.aaa3769)

(University of Wisconsin-Madison / Science, 20.03.2015 - NPO)