Category Archives: Sea Level Rise

Greenland’s Rapid Melt Will Mean More Flooding


The Greenland Ice Sheet, seen here in Oct. 2018, is melting at a rapidly accelerating rate because of Earth’s warming climate. As the ice melts into the ocean, it raises the sea level around the world, causing flooding and other damage to coastal communities. Credits: NASA/JPL-Caltech

By NASA;

The Greenland Ice Sheet is rapidly melting, having lost 3.8 trillion tons of ice between 1992 and 2018, a new study from NASA and the European Space Agency (ESA) finds. The study combined 26 independent satellite datasets to track global warming’s effect on Greenland, one of the largest ice sheets on Earth, and the ice sheet melt’s impact on rising sea levels. The findings, which forecast an approximate 3 to 5 inches (70 to 130 millimeters) of global sea level rise by 2100, are in alignment with previous worst-case projections if the average rate of Greenland’s ice loss continues.

Changes to the Greenland and Antarctic ice sheets are of considerable societal importance, as they directly impact global sea levels, which are a result of climate change. As glaciers and ice sheets melt, they add more water to the ocean. Increasing rates of global warming have accelerated Greenland’s ice mass loss from 25 billion tons per year in the 1990s to a current average of 234 billion tons per year. This means that Greenland’s ice is melting on average seven times faster today than it was at the beginning of the study period. The Greenland Ice Sheet holds enough water to raise the sea level by 24 feet (7.4 meters).

The paper, published Dec. 10 in Nature, is the result of an international collaboration between 89 polar scientists from 50 scientific institutions supported by NASA and ESA. The Ice Sheet Mass Balance Inter-comparison Exercise, or IMBIE, used well-calibrated data from 13 NASA and ESA satellite missions to create the most accurate measurements of ice loss to date. The team found that half of the loss is tied to surface ice melting in warmer air. The rest of the loss is the result of factors such as warmer ocean temperatures, iceberg calving and the ice sheet shedding ice into the ocean more quickly.

“There are climate projections that are based on models of varying levels of complexity and observations, but they have large uncertainties. Our study is purely an observational one that tests those uncertainties. Therefore, we have irrefutable evidence that we seem to be on track with one of the most pessimistic sea level rise scenarios,” said Erik Ivins, second author and lead scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Greenland is home to the only permanent ice sheet outside Antarctica. The sheet covers three-fourths of Greenland’s land mass. But in the last 26 years, Greenland’s melting ice has added 0.4 inches (11 millimeters) to sea level rise. Its cumulative 3.8 trillion tons of melted ice is equivalent to adding the water from 120 million Olympic-size swimming pools to the ocean every year, for 26 years.

“As a rule of thumb, for every centimeter rise in global sea level, another 6 million people are exposed to coastal flooding around the planet,” said Andrew Shepherd, lead author and scientist from the University of Leeds in the United Kingdom. “On current trends, Greenland ice melting will cause 100 million people to be flooded each year by the end of the century, so 400 million in total due to sea level rise.”

In addition to storm surges and high tides that will increase flooding in many regions, sea level rise exacerbates events like hurricanes. Greenland’s shrinking ice sheet also speeds up global warming. The vast expanse of snow and ice helps cool down Earth by reflecting the Sun’s rays back into space. As the ice melts and retreats, the region absorbs more solar radiation, which warms the planet.

The new study will contribute to the evaluation and evolution of sea level rise models used by the Intergovernmental Panel on Climate Change in evaluating risks to current and future populations. The results of the study currently appear consistent with the panel’s worst-case projections for sea level rise in the next 80 years.

“The full set of consequences of future melt from the Greenland Ice Sheet remain uncertain, but even a small increase in sea level can have devastating effects on ports and coastal zones, cause destructive erosion, wetland flooding, and aquifer and agricultural soil contamination with salt,” said Ivins.

This is the third IMBIE study on ice loss as a result of global warming. IMBIE’s first report in 2012 measured both Greenland and Antarctica’s shrinking ice sheets, finding that the combined ice losses from Antarctica and Greenland had increased over time and that the ice sheets were losing three times as much ice as they were in the early 1990s. Antarctica and Greenland continue to lose ice today, and that rate of loss has accelerated since the first IMBIE study.

IMBIE is supported by the NASA Earth Science Division and the ESA Climate Change Initiative.

Original Article; NASA (12-10-2019)

Unprecedented and worrying rise in sea levels

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Indian Ocean. Photograph courtesy of: © Isabelle Duflo

Excerpts;

A new study has discovered new evidence of sea-level variability in the central Indian Ocean.

The study, which provides new details about sea levels in the past, concludes that sea levels in the central Indian Ocean have risen by close to a meter in the last two centuries…

Read Full Article; Science Daily (12-23-2019)

Great Barrier Reef study shows how reef copes with rapid sea-level rise

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Great barrier of reef, Australia. Photo source: ©© Secruza

Excerpts;

A survey of coral reef cores on the Great Barrier Reef has revealed how it has responded to recent periods of rapid sea-level rise. The study, covering the past 9000 years, has revealed a system in delicate balance.

Read Full Article; Science Daily (12-03-2019)

Great Barrier Reef health outlook downgraded to “very poor” due to ocean warming; CBS News (08-30-2019)

Why the Great Barrier Reef is in danger; MNN (09-07-2018) (09-12-2018)

Video Captures the Violent Act of Coral Bleaching, LiveScience (08-17-2016)

Global warming is transforming the Great Barrier Reef; Science Daily (04-18-2018)
A new study shows that corals on the northern Great Barrier Reef experienced a catastrophic die-off following the extended marine heatwave of 2016…

Great Barrier Reef coral bleaching has started early, biologist says; Guardian UK (01-19-2018)
Warm water has already begun bleaching coral on the Great Barrier Reef, weeks ahead of the period with highest forecast risk. Satellite data suggest widespread bleaching is possible by March…

A Close-Up Look at the Catastrophic Bleaching of the Great Barrier Reef; Yale E360 (04-10-2017)
Scientists are reporting the second mass bleaching in the Great Barrier Reef in the last year. In a Yale Environment 360 interview, researcher Terry Hughes says these events have damaged two-thirds of the world’s largest coral reef and are directly caused by global warming…

Coral bleaching hits 93% of Great Barrier Reef, Video, Science Daily (04-21-2016)
Australia’s Great Barrier Reef is suffering its worst coral bleaching in recorded history with 93 percent of the World Heritage site affected, scientists say as they reveal the phenomenon is also hitting the other side of the country…

Great Barrier Reef: the scale of bleaching has the most sober scientists worried, Guardian UK (04-16-2016)
I have dived hundreds of times, with different teams of scientists, along the reef. Yet the scale of this bleaching event has even the most sober and senior coral reef scientists worried. If the rhetoric from marine biologists is to be believed, then the Great Barrier Reef is now in the grip of a “bommie apocalypse”…

Great Barrier Reef’s Unprecedented Threat From Dredging, Dumping; Guardian UK (05-07-2014)
The impact of dredging and dumping sediment on the Great Barrier Reef has been far greater than the mining industry has claimed, with nearly 150m tonnes of new dredging set to take place in the reef’s waters, a study shows…

Worst floods for 50 years bring Venice to ‘its knees’

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Acqua alta, Venice, Italy. Photograph: © SAF — Coastal Care

Excerpts;

The worst flooding to hit Venice in more than 50 years has brought the historic city to its knees. Local authorities in the Italian lagoon city called for a state of emergency to be imposed…

Read Full Article; CNN (11-13-2019)

Two people die as Venice floods at highest level in 50 years; Guardian UK (11-13-2019)
Flood levels in the lagoon city reached the second-highest level since records began in 1923 as a result of the acqua alta, which hit 1.87 metres (74in). More than 85% of Venice was flooded.
‘This is result of climate change,’ says Venice mayor, who declares state of emergency…

Sea levels to continue rising after Paris agreement emission pledges expire in 2030


Photograph: © SAF — Coastal Care

Excerpts;

Sea levels will continue to rise around the world long after current carbon emissions pledges made through the Paris climate agreement are met and global temperatures stabilize, a new study indicates.

The new study is the first to quantify how much sea level would rise from the carbon emissions pledged under the Paris agreement. The researchers found that emissions released during the initial 15-year period of the agreement would cause sea levels to rise by about 20 centimeters by the year 2300…

Read Full Article; Science Daily (11-04-2019)

Rising sea levels pose threat to homes of 300m people – study; Guardian UK (10-29-2019)
More than three times more people are at risk from rising sea levels than previously believed, research suggests…

Coastal Warning: An Unwelcome Messenger on the Risks of Rising Seas; By Orrin H. Pilkey; Yale E360 (12-06-2018)

California King Tides Project: January 10-12 and February 8-9, 2020


Butterfly Beach, California. Photograph: © SAF — Coastal Care
“King tide” is the informal term generally used to describe an exceptionally high tide, which most often occurs when the Moon and the Sun are aligned and their gravitational pull on the Earth is at its strongest.NASA, AeroTech News

Excerpts;

The California King Tides Project helps people visualize future sea level by observing the highest high tides of today. You can help by taking and sharing photos of the shoreline during King Tides to create a record of the changes to our coast from sea level rise.

Find out at what time and how high the King Tides will be near you. Check back here in December to find a calendar of King Tides events hosted by local community organizations…

Read Full Article; California Coastal Commission (10-31-2019)

NASA helps California get ahead of coastal flooding (08-26-2019)
NASA in cooperation with the U.S. Geological Survey is helping emergency planners in Southern California get a more complete picture of the increasing risk of coastal flooding by looking at the highest of tides —”king tides…”

From Indonesia to Ingonish, some bones won’t stay buried


El Morro Cemetery, Puerto Rico. Photo source: ©© Kevin Baird.
“A cemetery is a place of respect for the dead and its location is chosen with the expectation that it will be there for generations. Cemeteries in coastal areas were not located with the expectation that they would flood or fall into the sea…”—William J. Neal & Orrin H. Pilkey (2013-©)

Excerpts;

As seas and storms erode coastlines, cemeteries are giving up their dead…

Read Full Article; Atlas Obscura (10-28-2019)

Cemeteries in the Sea; By William J. Neal & Orrin H. Pilkey; By Orrin H. Pilkey & William J. Neal (11-01-2013)
“Cemeteries by the sea are silent sentinels. Like lighthouses and coastal fortifications, they bear dates of former times when they were on high and dry land…”

Our coastal cemeteries are falling into the sea; By Orrin H. Pilkey & William J. Neal
Cemeteries in coastal areas were not located with the expectation that they would flood or fall into the sea. But most of the world’s ocean and estuarine shorelines are eroding — some slowly like California’s rocky coasts, and others rapidly like the Carolinas’ barrier island coasts…

Rising sea levels pose threat to homes of 300m people – study

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Severe coastal erosion in the Pacific Northwest, Washington state. Photograph courtesy of: ©Norma Longo.
“Cape Shoalwater, Washington is the fastest eroding stretch of land on the west coast, maybe even the entire Western Hemisphere.” —Eddie Jarvis.

Excerpts;

Figure based on new analysis of coastlines is more than three times previous estimate.

More than three times more people are at risk from rising sea levels than previously believed, research suggests.

Land that is currently home to 300 million people will flood at least once a year by 2050 unless carbon emissions are cut significantly and coastal defences strengthened, says the study, published in Nature Communications. This is far above the previous estimate of 80 million…

Read Full Article; Guardian UK (10-29-2019)

New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding; Nature Communication (10-29-2019)

The only answer to rising seas is to retreat; By Orrin H. Pilkey & Keith C. Pilkey; The News & Observer (10-18-2017)
Except for the timing, there is no controversy among scientists regarding sea level rise. Defending the coast and holding the shoreline in place ultimately will be futile. With a three-foot or a six-foot sea level rise, we will retreat, probably beginning within the next 50 years…

“Seawalls Kill Beaches,” Open Letters by Warner Chabot And Rob Young, (10-03-2014)

A softer approach, living shorelines as an alternative to a hardened coast; PortCity (05-12-2018)
Research over the last decade points toward the pursuit of living shorelines for coastal landowners seeking erosion control.But, with regulatory lag and miles of shoreline lost each year to harsh structures, it’s not always easy…

“Living Shorelines” Will Get Fast Track to Combat Sea Level Rise; Scientific American (07-06-2016)
As sea levels rise along U.S. coasts, it may soon get easier for people and local governments to obtain federal permits to build what are known as “living shorelines,” natural or nature-based structures designed to protect communities and infrastructure from extreme storms and flooding even as they protect habitat.

“A Never-Ending Commitment”: The High Cost of Preserving Vulnerable Beaches; ProPublica (09-27-2018)

Beach rebuilding efforts won’t stave off climate change impacts forever; Guardian UK (09-20-2018)

Is Your Home At Risk Of Flooding From Rising Seas By 2050? Check This Map; BuzzFeed News (11-13-2018)

Coastal property was once king. Fears of climate change are undermining its value; The WSJ (10-31-2018)
In a growing number of coastal communities, homes near the sea are appreciating more slowly than those inland. That’s bad news for people on the beach, good news for those farther away…

Coastal residents need to set aside money now to cope with future flooding; Sun Sentinel (07-10-2018)
Sea-level rise is a national economic insecurity. According to the National Ocean Service, 39 percent of the U.S. population in 2010 lived in counties that are on shorelines…

Coastal homes could see flood insurance premium going up again, and that’s only the beginning; Miami Herald (07-24-2018)

Sea level rise is already eroding home values, unbeknownst to their owners; NOLA (08-21-2018)

Rising seas threaten nearly $1 trillion worth of US homes, and most of them are moderately priced; CNBC (10-18-2017)

Sea Level Rise Will Reshape U.S. Population In All 50 States; Yale E360 (04-19-2017)
Sea level rise could cause mass migrations that will affect not just the United States’ East Coast, but reshape communities deep in the heart of the country, according to new research…

Surrendering to rising seas; Scientific American (08-2018)
Coastal communities struggling to adapt to climate change are beginning to do what was once unthinkable: retreat…

Let’s end war with ocean, Op-Ed by Orrin H. Pilkey (04-2017)
The immediate future most certainly holds more miles of sandbags, resulting in more narrowed and ugly beaches.But this trend can be halted and reversed. Now is the time to make peace with the ocean.The time is now to stop sandbagging, both physically with no more shore-hardening structures, and politically with no more exceptions to the intent of the rules, no more undermining existing legislation, and a return to enforcement…