How coral reefs can help us weather climate change

Sea levels are rising with the intensification of tropical cyclones, and this is bad news for the nearly 200 million people living on the coasts of the globe. But we should not forget that over millions of years, evolution has fine-tuned one species of marine creatures to build and maintain the integrity of giant barriers that can mitigate the ferocious power of the ocean for us.
Yeah, it's coral. The reefs created by these organisms are well known to scientists and surfers for their ability to absorb the shocks of rolling waves and create large gaps between them. Now, thanks to new research, we can fully understand how important these environmental builders have become. A recently published paper offers the first global synthesis of coral reef activities aimed at reducing hazards and adapting to climate change.

Coral reefs reduce wave energy by up to 97 percent, the study said. The crest of the reef, the shallowest section of water that bears the first shock of the wave, dissipates most of the energy, absorbing about 86 percent of the wave’s power before it reaches the surface of a reef or lagoon. Without such protection, coastal communities will face the challenges posed by rising storm waves and rising sea levels as a result of climate change.

“Coral reefs effectively serve as the first line of defense against incoming waves, storms and rising seas,” said Michael Beck, lead oceanologist and co-author of the study. 200 million people in more than 80 countries will be at risk if we do not protect and restore coral reefs.
About 44 percent of all people live within 100 kilometers of the coast, UN experts say. And while global warming is rapidly raising sea levels and contributing to increasingly severe coastal flooding, coral reefs could be a natural solution to a huge man-made problem.
But more than that, they could do it more efficiently and economically than even the best engineers in the world. The average cost of building an artificial breakwater is $20,000 per meter, the authors say, while coral reef reconstruction projects require only about $1,290 per meter.
In other words, saving coral reefs is 15 times cheaper than trying to mimic them with concrete.
“Coral reefs are beautiful creations of nature, which, if healthy, can provide opportunities to reduce the force of waves, comparable to many man-made coastal defense structures, while adapting to rising sea levels,” says Kurt Storlazzi, an American oceanographer and co-author of the study. “This work demonstrates that regenerating coral reefs can be a cost-effective way to reduce the dangers faced by coastal communities due to the combination of intensifying storms and rising sea levels.”

Scientists analyzed 250 early papers on coral reefs to digitally map their wave-slicing abilities. On average, only about 3 percent of the wave’s energy passed through the reef, and most of it was ejected where the reef’s crest contacts the open ocean. The exact amount of energy released depends on several factors, such as the depth of the reef and the unevenness of its surface.
Shallow and rugged reefs are the most effective barriers, the study said, making them invaluable natural resources, as man-made climate change has raised sea levels by about a meter and significantly increased the number of category 4 and 5 hurricanes. These reefs can save us from ourselves if we give them the chance. Corals around the world are under threat from human activities, including water pollution, introduction of invasive species and, of course, climate change. For example, the warm and acidic waters of the Caribbean Sea have a particularly strong impact on coral species with uneven surfaces and processes, which may soon be on the list of species on the verge of survival.
But while ocean acidification and rising water temperatures can prove deadly to corals, there is some evidence that these organisms are able to withstand such sudden changes, but this requires little human intervention.

“There are many fears about the future of coral reefs due to climate change, but there are many reasons for optimism, in particular, if we manage to tame other local factors such as pollution and technological development,” said Professor of Biology Fiorenza Micheli.
Conservation efforts often focus on remote reefs, but the authors believe that coral formations in the vicinity of humans should receive maximum attention. Not only are they at greatest risk from pollution, technology and overfishing; these reefs have the potential to directly save civilization. About 197 million people around the world live less than 10 meters above sea level and 50 kilometers from coral reefs, and they will face enormous costs from natural disasters if these reefs die.

“This study demonstrates that the restoration and conservation of coral reefs is an important and budgetary solution to reduce coastal hazards,” says biologist Filippo Ferrario.
Here is a list of 15 countries that are fully protected by coral reefs. They are ranked by the number of people able to reap the benefits provided by these organisms:

Indonesia: 41 million
India: 36 million
Philippines: 23 million
China: 16 million
Vietnam: 9 million
Brazil: 8 million
United States: 7 million
Malaysia: 5 million
Sri Lanka: 4 million
Taiwan: 3 million
Singapore: 3 million
Cuba: 3 million
Hong Kong: 2 million
Tanzania: 2 million
Saudi Arabia: 2 million

Source: facepla.net