Tag Archives: Sea Level Rise

Indonesia plans to relocate its capital from Jakarta

jakarta-flood
Flooding, Jakarta. Photo source: ©© Mulya Amri

Excerpts;

Indonesia plans to move its capital city from Jakarta, according to the country’s planning minister. Jakarta is home to more than 10 million people according to the United Nations, with an estimated 30 million in the greater metropolitan area. The nation is prone to flooding and is sinking at an alarming rate…

Read Full Article; CNN (04-29-2019)

Can the $40 Billion Great Garuda Project Stop Jakarta From Sinking Into the Sea? Inhabitat (10-16-2014)
Indonesia’s capital, Jakarta, is sinking into the sea. And forget the fuss about Venice dropping at a rate of 0.08 inches per year, Jakarta – home to 10 million people and counting – is sinking at between 2.9 and 6.7 inches per year, as some areas submerge faster than others. While rising sea levels are a contributing factor to this, by far the greater cause is unchecked groundwater extraction from below the city to provide fresh water to the ever-growing population. To try to stave off the impending inundation of sea water, the city has engaged Dutch firm Witteveen+Bos to manage a $40 billion land reclamation and sea wall project that will construct 17 new islands and take an estimated 30 years to complete…

Sinking Jakarta Starts Building Giant Wall as Sea Rises, Bloomberg (11-11-2014)
Jakarta, a former Dutch trading port, is one of the world’s megacities most at risk from rising sea levels. That’s because parts of the metropolis of almost 30 million people are sinking by as much as 6 inches a year, more than 10 times faster than the sea is rising…

The Great Wall of Jakarta, Reuters (12-22-2014)
In an effort to save Jakarta from drowning, an ambitious plan has been endorsed. The centerpiece of the plan will be an outer seawall built on reclaimed land several miles out in Jakarta Bay. Jakarta will need to assess the Giant Sea Wall against “a range of options to see if it makes economic sense…

Sea wall planned to save sinking Jakarta, Al Jazeera (11-25-2014)
Environmentalists say project to protect reclaimed land in Indonesia could wipe out coastal and fishing communities…

Antarctica’s Effect on Sea Level Rise in Coming Centuries


Thwaites Glacier. Credits: NASA/James Yungel.

Excerpts;

There are two primary causes of global mean sea level rise — added water from melting ice sheets and glaciers, and the expansion of sea water as it warms. The melting of Antarctica’s ice sheet is currently responsible for 20-25% of global sea level rise.

But how much of a role will it play hundreds of years in the future?

Scientists rely on precise numerical models to answer questions like this one. As the models used in predicting long-term sea level rise improve, so too do the projections derived from them. Scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California, have discovered a way to make current models more accurate. In doing so, they have also gotten one step closer to understanding what Antarctica’s ice sheet — and the sea level rise that occurs as it melts — will look like centuries from now.

“Unlike most current models, we included solid Earth processes — such as the elastic rebound of the bedrock under the ice, and the impact of changes in sea level very close to the ice sheet,” said JPL’s Eric Larour, first author of the study. “We also examined these models at a much higher resolution than is typically used — we zoomed in on areas of bedrock that were about 1 kilometer instead of the usual 20 kilometers.”

The scientists found that projections for the next 100 years are within 1% of previous projections for that time period; however, further into the future, they observed some significant differences.

“We found that around the year 2250, some of these solid Earth processes started to offset the melting of the ice sheet and the consequent sea level rise,” Larour said. In other words, they actually slowed the melting down.

The team noted that a hundred years even further into the future — by 2350 — this slowdown means that the melting of the ice sheet is likely to contribute 29% less to global sea level rise than previous models indicated.

“One of the main things we learned was that as grounded ice retreats inland, the bedrock under it lifts up elastically,” said Erik Ivins, a co-author of the study. “It’s similar to how a sofa cushion decompresses when you remove your weight from it. This process slows down the retreat of the ice sheet and ultimately the amount of melting.”

Although this sounds like good news, the scientists say it’s important to keep it in perspective. “It’s like a truck traveling downhill that encounters speed bumps in the road,” said Larour. “The truck will slow down a bit but will ultimately continue down the hill” — just as the ice sheet will continue to melt and sea level will continue to rise.

The breakthrough of this study, he added, was to “reach resolutions high enough to capture as many of these ‘speed bumps’ as possible and determine their effects in Antarctica while also modeling sea level rise over the entire planet.”

The study, titled “Slowdown in Antarctic Mass Loss from Solid Earth and Sea-Level Feedback,” was published today in Science.

Original Article, NASA (04-25-2019)

Even Antarctica’s Coldest Region Is Starting to Melt


The Antarctic. Photo courtesy of: © Denis Delestrac

Excerpts:

East Antarctica is the coldest spot on earth, long thought to be untouched by warming. But now the glaciers and ice shelves in this frigid region are showing signs of melting, a development that portends dramatic rises in sea levels this century and beyond…

Read Full Article; Yale E360 (03-28-2019)

A French beach cleared of homes shows NC the way; By Orrin H. Pilkey

xynthia-mayor-official
La Faute sur Mer’s former mayor (left) and Vendée’s senator (right) in front of an aerial view of the 2 inundated towns of L’Aiguillon and La Faute sur Mer, Vendée, France. In April 2016, overturning a previous 4 years jail sentence, the former mayor has been handed in appeal, a two-year suspended sentence in connection with the deaths of 29 people during Storm Xynthia in 2010. Captions: Coastal Care. Photo source: ©© Sénat

Excerpts;

Surprising to me, the French are ahead of the United States, and particularly ahead of North Carolina’s policies on preparation for the rising sea’s impact.

The problems of the French coast are much like the problems of the Carolinas…

Read Full Article; News Observer (02-24-2019)

Coastal Warning: An Unwelcome Messenger on the Risks of Rising Seas; By Orrin H. Pilkey; Yale E360 (12-06-2018)
Marine scientist Orrin Pilkey has long been cautioning about sea level rise and the folly of building and rebuilding along coastlines. In an interview with Yale Environment 360, he talks about why an eventual retreat from oceanfront property on the U.S. coast is inevitable…

High-tide flooding disrupts local economic activity


Sandbagged, trashed beach at South Nags Head, N.C. in February 1987, with some evidence of bags that have been torn or ruptured and have leaked sand. The scarp under the houses indicates that storm waves are topping the bags, and buildings were damaged or lost in the end. Captions and Photo courtesy of: © Orrin Pilkey.

Excerpts;

Evaluation of observed sea level rise impacts to date has emphasized sea level extremes, such as those from tropical cyclones. Far less is known about the consequences of more frequent high-tide flooding. Empirical analysis of the disruption caused by high-tide floods, also called nuisance or sunny-day floods, is challenging due to the short duration of these floods and their impacts.

Through a novel approach, we estimate the effects of high-tide flooding on local economic activity. High-tide flooding already measurably affects local economic activity in Annapolis, Maryland, reducing visits to the historic downtown by 1.7% (95% confidence interval, 1.0 to 2.6%). With 3 and 12 inches of additional sea level rise, high-tide floods would reduce visits by 3.6% (3.2 to 4.0%) and 24% (19 to 28%), respectively. A more comprehensive understanding of the impacts of high-tide flooding can help to guide efficient responses from local adaptations to global mitigation of climate change…

Read Full Article; News Observer (02-15-2019)

US coastal businesses hit by everyday impact of climate change, study shows; Guardian UK (02-16-2019)

Vecino de Bocagrande ‘surfea’ en plena calle inundada por lluvia


Cartagena. Photo courtesy of: photo courtesy of: © Nelson Rangel-Buitrago

Excerpts;

“Our national government will invest 51 million us dollars to solve this with…. hard structures!”- Nelson Rangel-Buitrago, Grupo de Geología, Geofísica y Procesos Marino-Costeros, Universidad del Atlántico Barranquilla, Atlántico, Colombia

Watch a Youtube Video; in Spanish by
El heraldo (02-15-2018)

Florida is drowning. Condos are still being built. Can’t humans see the writing on the wall?


A Gulf Coast of Florida community. Captions and Photograph courtesy of:© Orrin H. Pilkey and J. Andrew G. Cooper

Excerpts;

People tend to respond to immediate threats and financial consequences – and Florida’s coastal real estate may be on the cusp of delivering that harsh wake-up call…

Read Full Article; Guardian UK (02-15-2018)

Column: The future of Florida’s beaches and the public’s right to know; Op Ed. by Orrin Pilkey (12-07-2015)

Florida has spent more than $100 million pouring more sand onto beaches in the past three years. Is it time to wave a white flag? Sun Sentinel (06-08-2018)
In South Florida’s war against the tides, it may be time to recognize that discretion is the better part of valor. For the past 70 years, the state of Florida has spent more than $1.3 billion on packing sand onto eroding beaches…

Column: High-rises spell the end for Florida beaches; By Orrin H. Pilkey and J. Andrew G. Cooper; Tampa Bay (07-25-2017)
Floridians are becoming more attuned to sea level rise and more familiar with nuisance flooding related to the rising sea. However, we believe there is less recognition that by century’s end it is likely that most of Florida’s major beaches will be permanently gone…

Reinforce and Build: The vicious cycle driving development on Florida’s most fragile beaches; by John Platt, Hakai Magazine (12-20-2016)

Gone with the wind: storms deepen Florida’s beach sand crunch; Reuters (02-16-2018)
Costs of so-called beach renourishments are a fraction of the total, measured in hundreds of millions of dollars, but the effort is crucial for Florida’s $67 billion tourism industry. And while sand needs are surging, there is not enough to go around…

Sand washes away as quickly as it can be dumped, Bathtub Beach, FL, TCPalm News (11-17-2017)
Between 2004 and 2014, some $13.6 million was spent on beach renourishment in Martin County, Florida. About $7.1 million came from local funds — your tax dollars. In the past two years, more than $6 million from a variety of sources has been spent to renourish and restore dunes at Bathtub Beach alone…

Factbox: Sifting Through U.S. Beach Sand Numbers; Reuters (02-16-2018)

Can Adding Sand to Beaches Save Them? How Stuff Works (04-13-2018)
The question is, can beach nourishment keep up with the ever-increasing forces of climate change or, like Sisyphus forever pushing his boulder up the hill, is adding sand to beaches an expensive, temporary fix to a long-term problem?..

“A Never-Ending Commitment”: The High Cost of Preserving Vulnerable Beaches; ProPublica (09-27-2018)
The U.S. government pays to dump truckloads of sand onto eroding beaches, in a cycle that is said to harm ecosystems and disproportionately benefit the rich…

A look at the billions of dollars behind beach renourishment: Is it worth it? WMBF (10-15-2018)

The end of the world’s most famous beaches; By Orrin H. Pilkey and J. Andrew G. Cooper (07-2017)
All over the world there are beaches lined with condos, hotels, restaurants and the like, in high-rise buildings (i.e., skyscrapers). Such beaches are generally the nation’s premier tourist areas, important to the local people and the local economy and prime spots for national and international vacationers. The powers that be in most of these places continue high-rise construction and seem oblivious of the sea level rise…

Sea rise along South Carolina coast accelerating faster than realized, researcher says


Cape Island in foreground, Cape Romain National Wildlife Refuge, South Carolina. Photograph courtesy of: Mary Edna Fraser, 2006 ©.

Excerpts;

Within 50 years, the sea off Charleston will be rising about one inch every five years — twice as fast as it was rising about a century ago and one-third faster than it was in 2000…

Read Full Article; Post And Courier (02-01-2019)

Huge Cavity in Antarctic Glacier Signals Rapid Decay


Thwaites Glacier. Credit: NASA/OIB/Jeremy Harbeck

By JPL / NASA;

A gigantic cavity – two-thirds the area of Manhattan and almost 1,000 feet (300 meters) tall – growing at the bottom of Thwaites Glacier in West Antarctica is one of several disturbing discoveries reported in a new NASA-led study of the disintegrating glacier. The findings highlight the need for detailed observations of Antarctic glaciers’ undersides in calculating how fast global sea levels will rise in response to climate change.

Researchers expected to find some gaps between ice and bedrock at Thwaites’ bottom where ocean water could flow in and melt the glacier from below. The size and explosive growth rate of the newfound hole, however, surprised them. It’s big enough to have contained 14 billion tons of ice, and most of that ice melted over the last three years.

“We have suspected for years that Thwaites was not tightly attached to the bedrock beneath it,” said Eric Rignot of the University of California, Irvine, and NASA’s Jet Propulsion Laboratory in Pasadena, California. Rignot is a co-author of the new study, which was published today in Science Advances. “Thanks to a new generation of satellites, we can finally see the detail,” he said.

The cavity was revealed by ice-penetrating radar in NASA’s Operation IceBridge, an airborne campaign beginning in 2010 that studies connections between the polar regions and the global climate. The researchers also used data from a constellation of Italian and German spaceborne synthetic aperture radars. These very high-resolution data can be processed by a technique called radar interferometry to reveal how the ground surface below has moved between images.

“[The size of] a cavity under a glacier plays an important role in melting,” said the study’s lead author, Pietro Milillo of JPL. “As more heat and water get under the glacier, it melts faster.”

Numerical models of ice sheets use a fixed shape to represent a cavity under the ice, rather than allowing the cavity to change and grow. The new discovery implies that this limitation most likely causes those models to underestimate how fast Thwaites is losing ice.

About the size of Florida, Thwaites Glacier is currently responsible for approximately 4 percent of global sea level rise. It holds enough ice to raise the world ocean a little over 2 feet (65 centimeters) and backstops neighboring glaciers that would raise sea levels an additional 8 feet (2.4 meters) if all the ice were lost.

Thwaites is one of the hardest places to reach on Earth, but it is about to become better known than ever before. The U.S. National Science Foundation and British National Environmental Research Council are mounting a five-year field project to answer the most critical questions about its processes and features. The International Thwaites Glacier Collaboration will begin its field experiments in the Southern Hemisphere summer of 2019-20.

How Scientists Measure Ice Loss

There’s no way to monitor Antarctic glaciers from ground level over the long term. Instead, scientists use satellite or airborne instrument data to observe features that change as a glacier melts, such as its flow speed and surface height.

Another changing feature is a glacier’s grounding line – the place near the edge of the continent where it lifts off its bed and starts to float on seawater. Many Antarctic glaciers extend for miles beyond their grounding lines, floating out over the open ocean.

Just as a grounded boat can float again when the weight of its cargo is removed, a glacier that loses ice weight can float over land where it used to stick. When this happens, the grounding line retreats inland. That exposes more of a glacier’s underside to sea water, increasing the likelihood its melt rate will accelerate.

An Irregular Retreat

For Thwaites, “We are discovering different mechanisms of retreat,” Millilo said. Different processes at various parts of the 100-mile-long (160-kilometer-long) front of the glacier are putting the rates of grounding-line retreat and of ice loss out of sync.

The huge cavity is under the main trunk of the glacier on its western side – the side farther from the West Antarctic Peninsula. In this region, as the tide rises and falls, the grounding line retreats and advances across a zone of about 2 to 3 miles (3 to 5 kilometers). The glacier has been coming unstuck from a ridge in the bedrock at a steady rate of about 0.4 to 0.5 miles (0.6 to 0.8 kilometers) a year since 1992. Despite this stable rate of grounding-line retreat, the melt rate on this side of the glacier is extremely high.

“On the eastern side of the glacier, the grounding-line retreat proceeds through small channels, maybe a kilometer wide, like fingers reaching beneath the glacier to melt it from below,” Milillo said. In that region, the rate of grounding-line retreat doubled from about 0.4 miles (0.6 kilometers) a year from 1992 to 2011 to 0.8 miles (1.2 kilometers) a year from 2011 to 2017. Even with this accelerating retreat, however, melt rates on this side of the glacier are lower than on the western side.

These results highlight that ice-ocean interactions are more complex than previously understood.

Milillo hopes the new results will be useful for the International Thwaites Glacier Collaboration researchers as they prepare for their fieldwork. “Such data is essential for field parties to focus on areas where the action is, because the grounding line is retreating rapidly with complex spatial patterns,” he said.

“Understanding the details of how the ocean melts away this glacier is essential to project its impact on sea level rise in the coming decades,” Rignot said.

The paper by Milillo and his co-authors in the journal Science Advances is titled “Heterogeneous retreat and ice melt of Thwaites Glacier, West Antarctica.” Co-authors were from the University of California, Irvine; the German Aerospace Center in Munich, Germany; and the University Grenoble Alpes in Grenoble, France.

Original Article; JPL / NASA (01-30-2019)