climate change
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Hawaii is losing its beaches
Kailua/USA (RPO). Sunbathing and surfing: These are the main goals of most Hawaii tourists. But that could end in the future. Because the archipelago is losing more and more beaches due to erosion. If sea levels are rising faster due to climate change, few beaches may be preserved.
Jenn Boneza remembers the days when the white sand beach near her home in Kailua, Hawaii was wide enough for sand castles to be built on. “It was really a beautiful beach,” says the 35-year-old mother of two. “And now he’s just gone.” What happened to parts of the beach in Kailua, an affluent suburb of Honolulu, is also emerging in many other places in the Hawaiian Islands.
According to geologists, a quarter of the sandy beaches on the main island of Oahu have already been lost, while 70 percent of the beaches on Kauai are affected by erosion. Experts fear that the problem will worsen significantly in the coming decades as sea levels rise more rapidly due to climate change. Then probably only a few beaches could be preserved, and the rest would have to be written off, says Dolan Eversole, a coastal geologist at the University of Hawaii.
The loss of so many beaches is a worrying prospect for the region. Because many tourists come because of those sandy coastlines, for sunbathing and for walks on the beach. These vacationers spend $11.4 billion a year in Hawaii, making tourism the tropical US state’s top employer. The disappearance of the beaches would also harm nature, because many animals and plants would lose important habitats. The Hawaiian monk seal, an endangered species, gives birth and nurses its pups on the beach. The green sea turtle, also endangered, lays its eggs in the sand.
Geology professor Chip Fletcher says researchers in Hawaii have yet to find accelerated sea-level rise associated with climate change. The erosion is due to a number of factors, including a historic, slow rise in sea levels that is thought to have started as early as the 19th century. Other causes include storms and human activity such as the construction of seawalls, jetties and dredging of estuaries. All of this disrupts the natural flow of the sand.
Partial battle already lost
However, in the coming decades, a faster rise in sea level due to global warming is also expected, which will accelerate erosion. In a hundred years, the sea level will probably be at least one meter higher than it is today, and the sea will advance further into today’s coastal areas. According to Professor Fletcher, anywhere in the United States, 60 to 80 percent of the coast is constantly being eroded. In Hawaii, however, this is more relevant because the economy and everyday life depend so much on the beaches.
The state is doing its best to keep the sand. In the tourist district of Waikiki, he supports a hotel project that aims to pump sand from the sea onto the beach for two to three million dollars. But different strategies are needed for different beaches, says Sam Lemmo of the State Bureau of Environmental Protection and Coastal Zones. In expensive Lanikai or Ewa Beach on Oahu, the battle is already lost because there are already seawalls and the beach is already badly eroded. The same is likely to be true for areas near the beach, where roads and other major infrastructure run and where dams already exist or have yet to be built.
Building dams exacerbates problems
Although dams protect individual properties from the approaching water, they promote erosion in the area, since waves with replenishment of sand no longer arrive there. The state therefore wants to protect previously undeveloped coasts. Recently, a Florida developer wanted to build luxury homes on sand dunes in north Oahu. “We practically went insane, built up our entire arsenal of weapons and got them to abandon the plan,” says Lemmo. “We are working hard to keep new construction projects out of these areas.”
The University of Hawaii is developing a beach management plan for Kailua that accounts for a one meter sea level rise. The state hopes this project will be followed by more specific plans for other stretches of beach. A selection strategy may be at work in Kailua. There are many luxury villas where President Barack Obama vacationed with his family, but there is no dam. Professor Fletcher suggests picking individual sections where an environmental fund then buys five or six contiguous lots. The buildings on it would be demolished and the site might be taken over by the beach.
As erosion spreads to more areas of Kailua, there will certainly be calls for dams to be built. “It’s going to be a very important moment,” Fletcher said. “If we allow the first house to build a dam, we’re probably dooming the entire beach over a period of a few decades. The alternative might be to designate some stretches of coastline in Kailua for the beach to live.”
Here is the photo gallery: Hawaii’s beaches are crumbling