Tag 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

oc-la-reunion
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

great-barrier-reef
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…

Antarctic ice sheets could be at greater risk of melting than previously thought


Antarctica. Photo courtesy of © Denis Delestrac for Coastal Care’s Photo of the Month, July and August 2018.

Excerpts;

Antarctica is the largest reservoir of ice on Earth — but new research by the University of South Australia suggests it could be at greater risk of melting than previously thought…

Read Full Article; Science Daily (12-02-2019)

315 billion-tonne iceberg breaks off Antarctica; BBC News (09-30-2019)
The Amery Ice Shelf in Antarctica has just produced its biggest iceberg in more than 50 years…

This Florida Keys neighborhood has been flooded for nearly 3 months


Photo source: ©© Bryan Elkus

Excerpts;

The flooding here and elsewhere is happening during so-called “king tides.” Those are times, mostly in the fall, when the moon’s gravitational pull means tides are higher than usual.

Read Full Article; NPR (11-28-2019)

Rising tides force Miami Beach residents to seek higher ground; CBS News (09-25-2019)

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…

California King Tides Project: January 10-12 and February 8-9, 2020; California Coastal Commission (10-31-2019)

Worst floods for 50 years bring Venice to ‘its knees’; CNN (11-13-2019)
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…

Indian Ocean Dipole spells flood danger for East Africa; The New Humanitarian (10-22-2019)
Hundreds of thousands of people in East Africa are affected by heavy rains and floods linked to record-breaking temperature changes in the Indian Ocean. As a result, higher evaporation off the African coastline is being dumped inland as rainfall: a simplified description of 2019’s positive Indian Ocean Dipole (IOD) episode…

New Earth mission will track rising oceans into 2030


The Jason-CS/Sentinel-6 mission that will track sea level rise, one of the clearest signs of global warming, for the next 10 years. Sentinel-6A, the first of the mission’s two satellites, is shown in its clean room in Germany and is scheduled to launch in November 2020. Credits: IABG

By NASA;

Earth’s climate is changing, and the study of oceans is vital to understanding the effects of those changes on our future. For the first time, U.S and European agencies are preparing to launch a 10-year satellite mission to continue to study the clearest sign of global warming — rising sea levels. The Sentinel-6/Jason-CS mission (short for Jason-Continuity of Service), will be the longest-running mission dedicated to answering the question: How much will Earth’s oceans rise by 2030?

By 2030, Sentinel-6/Jason-CS will add to nearly 40 years of sea level records, providing us with the clearest, most sensitive measure of how humans are changing the planet and its climate.

The mission consists of two identical satellites, Sentinel-6A and Sentinel-6B, launching five years apart. The Sentinel-6A spacecraft was on display for the media on Nov. 15 for a last look in its clean room in Germany’s IABG space test center. The satellite is being prepared for a scheduled launch in November 2020 from Vandenberg Air Force Base in California on a SpaceX Falcon 9 rocket.

Sentinel-6/Jason-CS follows in the footsteps of four other joint U.S.-European satellite missions — TOPEX/Poseidon and Jason-1, Ocean Surface Topography/Jason-2, and Jason-3 — that have measured sea level rise over the past three decades. The data gathered by those missions have shown that Earth’s oceans are rising by an average of 0.1 inches (3 millimeters) per year.

Sentinel-6/Jason-CS will continue that work, studying not just sea level change but also changes in ocean circulation, climate variability such as El Niño and La Niña, and weather patterns, including hurricanes and storms.

“Global sea level rise is, in a way, the most complete measure of how humans are changing the climate,” said Josh Willis, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “If you think about it, global sea level rise means that 70% of Earth’s surface is getting taller — 70% of the planet is changing its shape and growing. So it’s the whole planet changing. That’s what we’re really measuring.”

Decades of space- and ground-based observations have documented Earth’s surface temperature rising at a rapidly accelerating rate. The oceans help to stabilize our climate by absorbing over 90% of the heat trapped on the planet by excess greenhouse gases, like carbon dioxide, that have been emitted into the atmosphere since the start of the Industrial Revolution.

As the oceans warm, they expand, increasing the volume of water; the trapped heat also melts ice sheets and glaciers, contributing further to sea level rise. The rate at which it is rising has accelerated over the past 25 years and is expected to continue accelerating in years to come.

Sentinel-6/Jason-CS will measure down to the millimeter how much global sea level rises during the 2020s and how fast that rise accelerates. As the rate increases, humans will need to adapt to the effects of rising seas — including flooding, coastal erosion, hazards from storms and negative impacts to marine life.

Along with measuring sea level rise, the mission will provide datasets that can help with weather predictions, assessing temperature changes in the atmosphere and collecting high-resolution vertical profiles of temperature and humidity.

As with its Jason-series predecessors, Sentinel-6/Jason-CS will gather global ocean data every 10 days, providing insights into large ocean features like El Niño events. However, unlike previous Jason-series missions, its higher-resolution instruments will also be able to provide data on smaller ocean features — including complex currents — that will benefit navigation and fishing communities.


One week’s worth of data from NASA’s Earth observing satellites show the rising sea level on Earth between Oct. 29 and Nov. 7, 2019. Areas in red show higher levels, while blue show the lowest. The joint U.S.-European Sentinel-6/Jason-CS mission will continue efforts to track sea level rise. Credits: NASA/JPL-Caltech

“Global sea level rise is one of the most expensive and disruptive impacts of climate change that there is,” said Willis. “In our lifetimes, we’re not going to see global sea level fall by a meaningful amount. We’re literally charting how much sea level rise we’re going have to deal with for the next several generations.”

Sentinel-6/Jason-CS is being jointly developed by the European Space Agency (ESA), the European Organisation for the Exploitation of Meteorological Satellite (EUMETSAT), NASA and the National Oceanic and Atmospheric Administration (NOAA) with funding support from the European Commission and support from France’s National Centre for Space Studies (CNES). NASA’s contributions to the Sentinel-6 mission are science instrument payloads for the two Sentinel-6 satellites, launch services for those satellites, ground systems supporting the science instruments operations and support for the international Ocean Surface Topography Science Team.

Original Article; NASA (11-20-2019)

Waterfront retreat: a Bay community faces rising seas and buyouts


Photograph: © SAF — Coastal Care

Excerpts;

Beset by sea level rise and increasing storm damage, most residents of the Delaware Bay community of Money Island have opted to take buyouts from the state and abandon their homes. An e360 video shows that for those who remain, the decision to stay or leave can be agonizing…

Read Full Article and Watch Video; Yale E360 (11-21-2019)

Rising sea levels pose threat to homes of 300m people – study; Guardian UK (10-29-2019)

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…

California prepares policy for coastal ‘retreat’; E & E News (12-07-2018)
Oceanfront homes could be demolished along California’s coastline under a groundbreaking proposal to preserve the state’s made-for-movies beaches before they’re destroyed by rising seawater. The California Coastal Commission plans to release guidance early next year for dealing with sea-level rise in residential areas…

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…

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…