For many scientists, there are only two types of material: living and dead. "It makes thinking nice and easy," says Paul Kench, a geologist with the University of Auckland in New Zealand.
Islands, for example, are generally assigned to the sphere of the inanimate. Kench, however, wants to convince the scientific world that the opposite is true. That's why he is currently spending much of his time swimming around with flippers in the emerald-green waters of the Indian Ocean.
Kench traveled to the Maldives with five fellow scientists. Together, they intend to fathom the true essence of the tropical archipelago. "These islands are like a growing organism, constantly changing and sometimes even ceasing to exist," says Kench.
The New Zealand scientist has studded this unusual body of islands with sensors to measure its growth. The other team members want to see how he does it, and so, equipped with masks and snorkels, they dive into the amazing underwater world of the islands' lagoons. Flat, rounded shapes with jagged edges and odd-looking spheres become visible. They see a forest of coral, whose chalky skeletons form the reefs. The islands owe their existence to the life-and-death cycle of these marine organisms.
A tube about as long as a forearm comes into sight in the midst of this bizarre underwater landscape, wedged between two table corals. Kench gives the thumbs-up signal and the other divers nod. The tube is one of the sediment traps they have set up. They are designed to collect limestone particles from dead corals, the grains that form the foundation for the magnificent beaches of this tropical paradise.
The volume of captured sediments reveals how much new sand is coming from the corals, material that contributes to the growth of the islands. "By taking these readings," Kench explains after surfacing from the dive, still a little out of breath, "we hope to come up with as precise an assessment as possible."
The solution to this question is of more than just academic interest. Like many other atoll islands, the Maldives are considered an endangered paradise, as global warming causes sea levels to rise. According to the grim scenario many scientists envision, the archipelagos, unprotected against the tides, are doomed.
"But this concept is much too simple," says Kench. He is, of course, aware of the explosive nature of such a statement.
Symbols of Climate Change
Like polar bears on their melting ice floes, the sinking island paradises have become symbols of climate change. In a calculated effort to draw attention to the plight of his country, Maldives President Mohamed Nasheed held an underwater cabinet meeting at the end of last year, just before the United Nations Climate Change Conference in Copenhagen. "If we want to save the world, saving the Maldives, I suggest, is a very good starting point," Nasheed said.
In this heated climate, Kench and his fellow scientists warn against drawing premature conclusions. Only last month, Kench and Arthur Webb of the Fuji-based Pacific Island Applied Geoscience Commission published a study whose results were completely unexpected.
The geomorphologists compared old aerial photographs taken in World War II with current satellite images. To their surprise, they found that most of the atolls they were studying had either grown or remained unchanged in the last few decades, even though the sea level has already risen by 12 centimeters (about 5 inches).
As soon as it was published, the study became ammunition in the political battle over global warming. Climate activists questioned its conclusions, which would normally be welcomed as good news. Skeptics of anthropogenic climate change, on the other hand, seized upon the study as evidence that all the excitement over global warming is completely unnecessary.
Time to Scrap the Model
Scientists find this polarization distressing. "We take climate change very seriously," says Kench. "But in order to correctly predict the real consequences for the atolls, we first have to understand how they will actually respond to rising sea levels in the future."
So far, research into the consequences of climate change has drawn on a relatively simplistic model, according to which the islands should have been shrinking for some time. Despite its weaknesses, the model is still used today, and it even played a role in studies for a report by the United Nations Intergovernmental Panel on Climate Change (IPCC). Kench and his fellow scientists, who refer to their atoll research group as REEForm, believe it is high time to scrap the model.
Considering the size of the public interest in the topic, we know surprisingly little about the dynamics of coral islands. Geomorphologists like Kench, who are familiar with the growth processes of atolls, are a rarity. Indeed, half of the world's experts in the field are part of his small team conducting research in the Maldives.