US city Miami could one day be underwater, just as many other cities worldwide

MIAMI: While Hurricane Irma has ravaged Miami and surrounding areas in southeastern US, the real problem is rising sea levels, a potentially disastrous problem that Miami shares with cities worldwide, experts said.

For the first time in recorded history, ocean levels are rising, after being stable for the last 5,000 or 6,000 years. The US National Ocean Service said global sea levels will likely continue to rise, and Miami residents said flooding due to rising sea level has worsened over the years.

Now, low lying cities worldwide, from Mumbai to Bangkok to Miami here in southern Florida, are under the same threat, as many are low lying and not built with sea level rise in mind.

While hurricanes and other storms can bring short term damage, slowly rising sea levels threaten to put cities permanently under water.

"It's not just about Miami. Any coastal city in the world, including Mumbai, Jakarta, Tokyo, Calcutta are all low lying coastal cities," John Englander, a leading expert and author on rising sea levels, told Xinhua.

"Sea level rise is becoming a problem in all of those places," he said. "Miami is good as an illustration, but if we think it's a Miami problem we're going to be misled."

"Because from Washington D.C. to London, England, those are cities on tidal rivers, and as the ocean height rises, those cities have more flooding too," said Englander, author of High Tide On Main Street: Rising Sea Level and the Coming Coastal Crisis.

The book was named as one of the top 50 books to read by Politico, a widely respected US news website.

"All over the world we have built as if sea level would not rise. Now that sea level has started to rise, we have to plan differently," he said.

"Really this is about every coastal city in the world," he noted.

Miami grabbed nationwide headlines over the weekend as a massive storm hit the area. Hurricane Irma ravaged the downtown area, causing floodwaters to surge to waist-high levels and making streets look like rivers.

But Miami does not need storms to cause flooding, as flooding from high sea levels can occur on sunny days due simply to high tides and the city's low lying position.

Other factors also contribute, such as the fact that the city lies on a bed of limestone, which is porous and allows water to seep through from underneath the treets, coming up through drains and flooding the streets.

Many cities in Asia are at risk as well.

Bangkok, capital of Thailand, tops the list of Asian cities at risk of flooding due to rising sea levels.

A 2015 government report found that Bangkok, home to around 14 million residents, could be underwater in 15 years due to rising sea levels.

The tourist paradise in 2011 saw the worst flooding in its history, which killed over 800 people and impacted 12 million others. The economy took a loss of over 40 billion US dollars, as supply chains were severely disrupted and business slowed to a halt.

A number of other low lying cities and countries are in particular danger, Englander said.

"Bangladesh and Vietnam are two low lying countries with tens of millions of people. Hong Kong is a mountainous island. But the development on the waterfront has all been done at very low level (close to the sea)," he said.

Scientists say Bangladesh, a low-lying country, will also be one of the world's hardest hit areas, as oceans warm up and polar ice melts, causing sea levels to rise.

Data from that country's Permanent Service for Mean Sea Level shows sea levels in the southwestern part of the country rose by around seven millimetres per year between 1980 to 2003. That is well above the global average of three millimetres between that time period.

A study by Germany's Potsdam Institute for Climate Impact Research has forecast that global sea levels will rise on average between 56 centimetres and 106 centimetres by 2100.

Some regions will be worse impacted than others. Those countries include India, Bangladesh, Japan, Argentina, Australia and South Africa.

At the same time, other areas will see a slightly less-than-average rise, including the Pacific Northwest in the United States, as well as Western Europe, the study found.

"The fact is that we have to start building higher," Englander said, referring to low-lying coastal cities worldwide.

"In some places, levies and seawalls can be built, perhaps pumps for a short period of time will solve the problem temporarily. But basically if you know that sea level is going to become three meters higher sometime in the next 50 or 100 or 150 years, the sooner we start building higher, the better," he said.

Miami residents told Xinhua that even at times of calm weather and sunshine, high tides can flood Miami's streets by several inches. Those are often known as king tides.

Englander said king ties are becoming a problem worldwide.

"You're seeing this in cities all over the world, that when we have a full moon high tide, and it pulls the oceans more strongly, they are getting more flooding," he said.

Back in Miami, the city boasts a large Cuban-American population, which has lived in the area since the 1960s and is often influential and wealthy. Recent immigrants have come from all over Latin America, and Spanish is often heard spoken on the street.

Southern Florida is also a major retirement destination for Americans nationwide, who want to spend their golden years soaking up the sun, and a playground for the rich and famous.

"If water is rising, you're in a basin by definition," Daniel Kreeger, executive director of the Association of Climate Change Officers, told Xinhua, over a meal at a Cuban restaurant.

The danger to Miami and surrounding areas is not necessarily in beachfront areas, despite many people's belief that beaches would be the main areas impacted, he said.

The area's many beaches are essentially dunes, and as one travels inland, the landscape becomes flat. That eventually backs up into swampland in the Florida everglades, which causes the local landscape to trap water. At a time of rising sea level, water may increasingly have nowhere to go.

"In that sort of situation, your problem is where do you push water when it comes on land? You can't push it into the ocean or the Everglades ...there's just no where to put it," he said.