Category Archives: Sea level rise

A key part of Antarctica is doomed to slow collapse

No matter how much the world cuts back on carbon emissions, a key and sizable chunk of Antarctica is essentially doomed to an “unavoidable” melt, a new study finds.

Associated Press, by Seth Borenstein, AP video produced by Teresa de Miguel, October 23, 2023

No matter how much the world cuts back on carbon emissions, a key and sizable chunk of Antarctica is essentially doomed to an “unavoidable” melt, a new study found.

Though the full melt will take hundreds of years, slowly adding nearly 6 feet (1.8 meters) to sea levels, it will be enough to reshape where and how people live in the future, the study’s lead author said.

Researchers used computer simulations to calculate future melting of protective ice shelves jutting over Antarctica’s Amundsen Sea in western Antarctica. The study in Monday’s journal Nature Climate Change found even if future warming was limited to just a few tenths of a degree more – an international goal that many scientists say is unlikely to be met – it would have “limited power to prevent ocean warming that could lead to the collapse of the West Antarctic Ice Sheet.”

“Our main question here was: How much control do we still have over ice shelf melting? How much melting can still be prevented by reducing emissions?” said study lead author Kaitlin Naughten, an oceanographer at the British Antarctic Survey. “Unfortunately, it’s not great news. Our simulations suggest that we are now committed to the rapid increase in the rate of ocean warming and ice shelf melting over the rest of the century.”

While past studies have talked about how dire the situation is, Naughten was the first to use computer simulations to study the key melting component of warm water melting ice from below, and the work looked at four different scenarios for how much carbon dioxide the world pumps into the atmosphere. In each case, ocean warming was just too much for this section of the ice sheet to survive, the study found.

Naughten looked at melting gatekeeper ice shelves, which float over the ocean in this area of Antarctica that is already below sea level. Once these ice shelves melt, there’s nothing to stop the glaciers behind them from flowing into the sea.

Naughten specifically looked at what would happen if somehow future warming was limited to 1.5 degrees Celsius (2.7 degrees Fahrenheit) over mid-19th century levels — the international goal — and found the runaway melting process anyway. The world has already warmed about 1.2 degrees Celsius (nearly 2.2 degrees Fahrenheit) since pre-industrial times and much of this summer temporarily shot past the 1.5 mark.

This undated image provided by British Antarctic Survey, shows the North Cove, in Antarctic. (Michael Shortt/British Antarctic Survey via AP)

Naughten’s study concentrated on the part of the West Antarctic Ice Sheet that is most at risk from melting from below, near the Amundsen Sea. It includes the massive Thwaites ice shelf that is melting so fast it got the nickname “the Doomsday Glacier.” West Antarctica is only one-tenth of the southern continent but is more unstable than the larger eastern side.

That part of Antarctica “is doomed,” said University of California Irvine ice scientist Eric Rignot, who wasn’t part of the study. “The damage has already been done.”

University of Colorado ice scientist Ted Scambos, who also wasn’t part of the study, said this ice sheet “eventually is going to collapse. It’s not a happy conclusion and it is one that I’m only saying reluctantly.”

Naughten doesn’t like to use the word “doomed,” because she said 100 years from now the world might not just stop but reverse carbon levels in the air and global warming. But she said what’s happening now on the ground is a slow collapse that can’t be stopped, at least not in this century.

“I think it’s unavoidable that some of this area is lost. It’s unavoidable that the problem gets worse,” Naughten told The Associated Press. “It isn’t unavoidable that we lose all of it because sea level rise happens over the very long term. I only looked in this study up to 2100. So after 2100, we probably have some control still.’’

No matter what words are used, Naughten said she and other scientists studying the area in previous research conclude that this part of Antarctica “couldn’t be saved or a lot of it couldn’t be saved.”

Naughten’s study did not calculate how much ice would be lost, how much sea level would rise and at what speed. But she estimated that the amount of ice in the area most at risk if it all melted would raise sea levels by about 1.8 meters (5.9 feet).

This 2020 photo provided by the British Antarctic Survey shows the Thwaites glacier in Antarctica. (David Vaughan/British Antarctic Survey via AP)

However, she said, that is a slow process that would play out through the next few hundred years through the 2300s, 2400s and 2500s.

Naughten said that may seem like a long way away, but noted that if the Victorians of the 1800s had done something to drastically change the shape of our world, we would not look well on them.

This type of sea level rise would be “absolutely devastating” if it happened over 200 years, but if it could be stretched out over 2,000 years, humanity could adapt, Naughten said.

“Coastal communities will either have to build around or be abandoned,” Naughten said.

While this part of Antarctica’s ice sheet is destined to be lost, other vulnerable sections of Earth’s environment can still be saved by reducing heat-trapping emissions so there is reason to still cut back on carbon pollution, Naughten said.

Twila Moon, deputy chief scientist at the National Snow and Ice Data Center who wasn’t part of the research, said she worries that most people will see nothing but doom and gloom in the research.

“I don’t see a lot of hope,” Naughten said. “But it’s what the science tells me. So that’s what I have to communicate to the world.”

Naughten quoted former NASA scientist Kate Marvel, saying “when it comes to climate change we need courage and not hope. Courage is the resolve to do well without the assurance of a happy ending.”


Menacing threat to Vallejo (and Benicia): Greenland’s rapidly shrinking ‘zombie ice’

IMPORTANT OCTOBER 24, 2023 UPDATE: A key part of Antarctica is doomed to slow collapse

Brendan Riley’s Solano Chronicles: Vallejo’s shoreline threatened by zombie ice

Flooding around the old Times-Herald and News-Chronicle building in 1967 on what’s now Curtola Parkway could occur again there and elsewhere in Vallejo without safeguards against predicted sea rise. (Vallejo Naval and Historical Museum files)

Vallejo Times-Herald, by Brendan Riley, September 8, 2022

Efforts to extend the shorelines of Vallejo and now-closed Mare Island Naval Shipyard, just across the Napa River, transformed bay and river waters into thousands of acres of low-lying land. But those efforts that spanned more than a century are threatened by “zombie ice” and other effects of global warming.

A new study, published Aug. 29 in the journal Nature Climate Change, describes part of Greenland’s rapidly shrinking ice sheet as zombie ice because it’s doomed to melt. The study says that by 2100 the melting ice sheet, no longer being replenished by glaciers getting less snow, will raise global sea levels a minimum of 10 inches and possibly as much as 2 ½ feet.

The sea rise from the Greenland ice sheet would be in addition to other Arctic and Antarctic ice melting due to global warming. Other documents, including a National Academy of Sciences report and a current State Sea-Level Rise Action Plan, warn that ice melt from all sources could cause two or more feet of sea rise on the West Coast as early as 2050 and five to six feet of rise by 2100.

Vallejo was part of a 2018 sea-rise study by a group called Resilient by Design. The study included an interactive risk-zone map on the Internet at sealevel.climatecentral.org/maps that shows the impact of rising levels. That easy-to-use link is available to anyone interested in seeing how our area would be impacted by varying amounts of sea rise.

The Resilient by Design link indicates that a foot of sea rise, without new levees, seawalls or other barriers, would flood a large strip of Vallejo’s Riverfront Park, along Wilson Avenue north of Tennessee Street. On Mare Island, part of its southwest tip would be underwater. Flooding also would occur on marshy land to the north, adjacent to State Route 37 and Dutchman Slough; and on SR37 near Black Point, several miles west of Vallejo.

Without protective barriers, a five-foot rise in the tideline would cause temporary or permanent flooding on most of SR37 (Sears Point Road) between Vallejo and Novato to the west. Much of the Mare Island fill land would be affected, including parts of Nimitz Avenue in the shipyard’s historic core.

In Vallejo, a long stretch of Mare Island Way and part of Curtola Parkway could flood. That would affect the municipal marina, Vallejo Yacht Club, a former State Farm Insurance building proposed as a new Police Department, the Ferry Building, Independence Park and the city boat launch area. Many locations to the south also could flood, including the city’s sewage treatment plant, Kiewit Pacific and the old Sperry Mill site.

Those projected flood zones would affect most, if not all, of the Vallejo and Mare Island shorelines that were expanded starting in the 1850s. Old navigation charts show the Navy, which opened its first West Coast shipyard in 1854, quickly filled in a strip of marshland along the river and constructed a seawall or quay where ships could tie up.

Expansion of Mare Island continued for decades, resulting in the shipyard increasing from less than 1,000 acres to its estimated 5,600 acres today. The new land was formed all the way around the island mainly by dredged mud from Mare Island Strait, the renamed stretch of the Napa River between the island and Vallejo, and by fill that was imported or obtained by digging into original higher ground on the island. Some of the new land is designated as marsh or tideland, but at least half of the new acreage has streets and roads and was used for all types of Navy shipyard activity.

On the Vallejo side, expansion into the Mare Island Strait added nearly 500 acres along the waterfront. The projects included one in the early 1900s that filled in a wide section of river that once separated Vallejo from South Vallejo.

The new land was formed by establishing a barrier that ran straight from the city boat ramp area almost to Lemon Street in South Vallejo. Mud dredged from the river on the west side of the barrier, or bulwark, was then pumped into what once had been navigable water and tideland on the other side.

The dredge-and-fill process that began on a large scale in 1913 took several years, creating more land and more direct road links between the two communities. Present-day Sonoma Boulevard between Curtola Parkway and Lemon Street would not exist without this project. The same goes for the sewage plant, Kiewit and many other businesses.

Without all the fill, you could anchor a boat at the present-day location of Anchor Self Storage on Sonoma Boulevard. The river reached what’s now Curtola Parkway on the north, and spread as far east as Fifth Street, where it turned into a marshy connection to Lake Dalwigk. On the south side, the railroad tracks that cross Fifth Street near Solano Avenue once ran along the water’s edge to the old Sperry Mill area.

More acreage was added to Vallejo’s shoreline in the 1940s near the Mare Island causeway, and in the 1960s as part of a massive redevelopment project that resulted in Vallejo’s entire Lower Georgia Street business district being bulldozed. Many longtime Vallejoans can remember walking out on a pier over tideland to board ferries that ran to Mare Island. That tideland is now the seawall area where people can park cars, take a ferryboat to San Francisco, have a drink or dine out, or go for a stroll.

Before redevelopment, the original Vallejo Yacht Club building stood in the same location as the current building – but on pilings over tideland. Much of the fill dirt for this waterfront extension came from Vallejo’s historic York Street Hill – the site of California’s Capitol in 1852 and 1853. The hill was scraped flat and trucked to the nearby riverfront.

In addition to the shoreline work, nearly 500 acres of usable land were formed by levees and fill in a marshy area where Larwin Plaza, now Vallejo Plaza, was built in 1960, along Sonoma Boulevard on the north side of Vallejo. White Slough, which flows into the Napa River, is on the edge of this shopping center. Traces of the marsh once extended nearly to Tennessee Street, several blocks to the south.

 

One Bay Area city may surrender land to the rising sea

A $900 million plan outlines how Hayward is preparing its sewage plants, natural gas power plant and 1,899 acres of marshes and tidelands for  a rising San Francisco Bay.

San Francisco Chronicle, by John King, July 2, 2021
LINKS TO THE SERIES: Mission Creek, Foster City, Hayward

By 2100, we may need to let rising waters cover portions of today’s shoreline, once and for all.

“You’ve got to be forward-thinking,” said Al Mendall, who served on the Hayward City Council from 2012 until December. “As a layperson, it seems obvious to me that we’re going to have to consider some form of retreat at some point. Not just in Hayward, but all around the Bay.”

Before San Francisco Bay’s shoreline was recognized as an irreplaceable resource, it was where cities put garbage dumps, highways and industrial zones. Out of sight, out of mind.

That’s why the west edge of Hayward north of Highway 92 includes two sewage plants and the natural gas power plant that opened in 2013. The white toll booths of the San Mateo-Hayward Bridge shimmer in the haze of automobile exhaust. Two stumpy hillocks conceal long-closed dumps.

But there also are 1,800 acres of protected marshes and tidelands, along with the Hayward Shoreline Interpretive Center built in 1986. Even as new warehouses and research parks are built next to such preserves, populations of species like the snowy plover and salt water harvest mouse continue to increase.

A group of pelicans rest in a channel near the Hayward Shoreline Interpretive Center last month.

Three pelicans rest in a channel near the Hayward Shoreline Interpretive Center last month. Carlos Avila Gonzalez / The Chronicle

It’s a juxtaposition that feels oddly timeless, but the placid scene can be deceptive. Already, several times each year, the combination of high tides and strong winds send sheets of water fanning across the trail from the interpretive center. Factor in the likelihood of significant sea level rise and the rare could become commonplace.

Sea level rise is fueled by higher global temperatures that trigger two forces: Warmer water expands oceans while the increased temperatures hasten the melting of glaciers on Antarctica and Greenland and add yet more water to the oceans.

Variations of this forecast — inconvenience followed by upheaval — are found all along the edges of San Francisco Bay. The difference is that Hayward worked out a detailed plan for what might lie ahead.

In February, Hayward’s City Council approved a set of strategies on how to adapt the shoreline zone to what climate change might bring between now and 2070. In some areas, the city would restore marshes or relocate trails. In others, new levees would shield industrial functions that cannot be moved, like the wastewater treatment facility.

John Blanchard/The Chronicle | GIS data from ART Bay Shoreline Flood Explorer, Hayward Area Shoreline Planning Agency, Scape and Hayward Regional Shoreline Adaptation Master Plan

The effort was led by Scape, a New York landscape architecture firm that has been active in sea-level-rise planning since Hurricane Sandy laid waste to coastal New York and New Jersey in 2012.

Unlike some bay settings — such as San Francisco’s heavily developed Mission Creek or Foster City, where a levee already protects homes — Hayward’s shoreline area offers room to maneuver. The area studied by Scape extends 3¼ miles from Highway 92 past the city’s northern border, while extending inland as much as 2 miles, past the power plant and research buildings to modest older homes.

Bicyclists are in the foreground riding along the Hayward Regional Shoreline. In the background the San Francisco skyline is visible amid fog and clouds.
San Francisco rises in the distance as cyclists ride through the Hayward Regional Shoreline last month. Carlos Avila Gonzalez / The Chronicle

Scape’s team of designers and engineers was selected in 2018 by the Hayward Area Shoreline Planning Agency, which includes representatives from the city, the East Bay Regional Park District and the Hayward Area Recreation and Park District.

The scale of the area captured the firm’s notice. So did the scale of Hayward’s ambitions.

“Plenty of cities and agencies are beginning to study risks. Hayward is one of the few places taking the next step and trying to offer solutions,” said Gena Wirth, who led the Scape team.

The 244-page plan lays out steps that can be taken in coming decades to stay ahead of the changes that would accompany daily tides 4 feet above current levels. Another 3.3 feet were added to account for the waves that could be triggered by a once-in-a-century storm.

“You want to look for how you can restore natural systems in a way that magnifies the overall benefits,” Werth said. “It’s all about establishing a vision and then breaking it down into bite-size components.”

None of this is easy — or cheap.

The combined price tag for everything in the plan tops $900 million, and there is no funding yet. But the recommendations are split into 26 projects of varying size — the idea being that pilot programs and smaller initiatives can kick off within the next few years, building momentum for larger projects in later decades.

“We have a lot of work ahead of us, definitely,” said Erik Pearson, the environmental services manager for Hayward’s Public Works department. “This is something we can use as a guide.”

The approach is applauded by scientists and officials wrestling with the challenge of a future in which the old danger — developers wanting to fill in the bay — is replaced by the need to keep the bay from reclaiming the low-lying lands at its edge.

“The level of sophistication and thoughtfulness is rare,” said Jessica Fain, the head planner of the Bay Conservation and Development Commission, a state agency created in 1967 to watch over the health of the bay. “There’s a range of solutions spelled out, and also a real dedication to pursuing them.”

This includes what potentially is the most controversial solution of all.

After it describes various natural methods to enhance and protect the shoreline, the plan devotes two pages to “managed retreat.” Or as Scape puts it, “a management strategy for retreating from vulnerable coastal areas” and “adapting to sea level rise over time.”

In one design scenario, Scape went so far as to study moving the Interpretive Center from the south end of the area, near Highway 92, to the top of one the hillocks that hide a former dump. Besides protecting the center from flooding, this option “maintains visibility of the structure and offers expansive views of the Bay.”

Al Mendall, who served on Hayward’s City Council from 2012 until last year, has been an advocate for Hayward’s planning efforts along its shoreline. Carlos Avila Gonzalez / The Chronicle

The final plan doesn’t include this move. But it emphasizes that if sea level rise matches current projections, the relocation of buildings and services “would likely be needed … long-term.”

That topic rarely is discussed, except in coastal areas that routinely flood or suffer dangerous levels of erosion. But Hayward officials inserted it deliberately.

“It’s important to mention that the concept exists” within the larger discussion, Pearson said. “At 4 feet, it doesn’t make sense to look at retreat. But at some point after that, it may be the best approach.”

Experts familiar with bay’s potential reach welcome the willingness of Hayward and the design team to acknowledge this.

“We need to stop thinking, ‘This is going to be here forever,’” said Letitia Grenier. She leads the resilient landscapes program at the San Francisco Estuary Institute, which advised Scape on the Hayward shoreline’s environment. “That’s not the way the world works. We need to learn to live with that.”

Will Travis, who was the executive director of the bay commission when it released its first sea level projections in 2007, has a similar view.

“The hard decisions will be what not to protect,” he said. “How you prioritize where to put your (limited) resources.”

The plan went to Hayward’s City Council on Feb. 16. It passed on a 5-0 vote.

Mendall, the former council member, was excited to see the council act in unison — and with no public opposition.

“We wanted something doable, not pie-in-the-sky,” he said. “It’s a tool for the next generation to preserve and protect the shoreline.”

An aerial view of the Hayward Regional Shoreline. In addition to restored marshes, it includes wastewater storage ponds and a field of solar panels. Carlos Avila Gonzalez / The Chronicle

CREDITS

REPORTING – John King

EDITING – Mark Lundgren

VISUALS – John Blanchard, Carlos Avila Gonzalez,
Guy Wathen, Alex K. Fong, Drawings animated in Mental Canvas

DESIGN AND DEVELOPMENT – Paula Friedrich

GIS DATA – BCDC (2017). Adapting To Rising Tides Bay Area Sea Level Rise Analysis & Mapping Project: SF Bay [spatial data file]. SF Bay Conservation and Development Commission

Greenland ice melt: Imagine a herd of 2000 elephants charging into the sea every SECOND!

2019 Arctic Report Card warns of California-sized algal blooms and imperiled livelihoods

PBS News Hour Science, December 10, 2019

A view of ice melting during a heatwave in Kangerlussuaq, Greenland is seen in this August 1, 2019 image obtained via social media. Photo by Caspar Haarloev from "Into the Ice" documentary via Reuters
A view of ice melting during a heatwave in Kangerlussuaq, Greenland is seen in this August 1, 2019 image obtained via social media. From 2002 to 2019, Greenland’s ice sheet lost 267 billion metric tons per year, on average, according to the 2019 Arctic Report Card. Photo by Caspar Haarloev from “Into the Ice” documentary via Reuters

“Two hundred sixty-seven billion tons of ice is really hard to put into context, but you could start by imagining a herd of elephants charging into the ocean from Greenland,” Osterberg said. “If you imagine that, we’re talking about 2,000 elephants charging into the ocean every second. That’s how much mass is going from Greenland into the ocean.” — Erich Osterberg, Dartmouth College climatologist

Dead seals, marked with bald patches, washing onto shores or floating in rivers. A 900-mile-long bloom of algae stretching off the coast of Greenland, potentially suffocating wildlife. A giant, underground storehouse of carbon trapped in permafrost is leaking millions of tons of greenhouse gases into the atmosphere, heralding a feedback loop that will accelerate climate change in unpredictable ways.

These are all bleak highlights from the 2019 Arctic Report Card, unveiled on Tuesday at the American Geophysical Union Fall Meeting. Published annually by the National Oceanic and Atmospheric Administration, the 14th iteration of this peer-reviewed report examines the status of the planet’s northern expanse and changes due to global warming, with potential consequences reaching around the globe.

In addition to scientific essays, this year’s report card for the first time delivers firsthand accounts from indigenous communities confronting the Arctic’s dramatic, climate-caused transformation. More than 70 such communities depend on Arctic ecosystems, which are warming twice as fast as any other location on the planet.

“In the northern Bering Sea, sea ice used to be present with us for eight months a year,” write members of the Chevak, Golovin, Nome, Savoonga, St. Paul Island, Teller, Unalakleet and Wales communities. “Today, we may only see three or four months with ice.”

The 2019 report documented sea ice at its second-lowest level ever recorded during a summer period, out of the last 41 years of satellite observations. This disappearing sea ice not only serves as a natural bridge for Native people hunting for food, but is central to creating the food in the first place. Its loss appears to be tied to dramatic shifts in marine life, as the sea ice helps create cold patches of water where Arctic fish thrive.

Sea ice cover in the Bering Sea on March 20, 2012 (left), and February 24, 2019 (right). Extremely low winter ice extents occurred in the Bering Sea in 2018 and 2019. NOAA Climate.gov image based on NASA satellite images from Worldview

Sea ice cover in the Bering Sea on March 20, 2012 (left), and February 24, 2019 (right). Extremely low winter ice extents also occurred in the Bering Sea in 2018 and 2019. NOAA Climate.gov image based on NASA satellite images from Worldview

Without those cooler pools, economically important marine species from the south — walleye pollock and Pacific cod, for example — are migrating northward, complicating business for the billion-dollar U.S. fisheries operating near Alaska in the Bering Sea.

“Major changes are occurring. For example, we closed the cod fishery early — first time in a long time — because of the decline in stocks there,” Retired Navy Rear Adm. Timothy Gallaudet, deputy NOAA administrator, said Tuesday at a press conference in San Francisco. “Our fishery science really is important to ensure we better manage what’s occurring.”

The Bering Sea and the Barents Sea appear to be the major centers of tumult. Fish leaving southern waters are challenging underwater species — like Arctic cod — for the northernmost territory, and may also consume the marine food typically eaten by seabirds, leaving other species hungry.

Over the last year, the Bering Sea has witnessed mass die-offs of short-tailed shearwaters near Bristol Bay, while the same has happened for ivory gulls in Canada, Greenland, Svalbard and Russia. Populations of Canadian ivory gulls have declined 70 percent since the 1980s, according to the report card.

“We as indigenous people have always adapted to our environment — whether something was imposed upon us or not,” Mellisa Johnson, executive director of the Bering Sea Elders, said Tuesday at a press conference in San Francisco. “The Mother Earth is doing what she needs to do because we are not taking care of our land and sea as given. We’re going to continue to adapt and move forward with the change.”

A fledgling short-tailed shearwater (Puffinus tenuirostris) on Heron Island, Australia. Shearwaters migrate north of the Bering Strait in the northern summer. Photo by Auscape/Universal Images Group via Getty Images

A fledgling short-tailed shearwater (Puffinus tenuirostris) on Heron Island, Australia. Shearwaters migrate north of the Bering Strait in the northern summer. Photo by Auscape/Universal Images Group via Getty Images

Ivory gull in Svalbard. Photo by Mats Brynolf via Getty Images

Ivory gull in Svalbard. Photo by Mats Brynolf via Getty Images

Those die-offs may also be due to the rise of algal blooms across the Arctic waterways. Red tides and other harmful algal blooms — typically a phenomena of warmer, southerly waters — are becoming more common in the north, as also detailed in last year’s report.

“Not only are we seeing these blooms in this particular region happening earlier, but they’re also substantially larger than what you would expect even later on in the year,” Karen Frey, a geographer and biogeochemist at Clark University in Worcester, Massachusetts, and co-author of the 2019 Arctic Report Card, told the PBS NewsHour.

Frey described the sea ice as a dark cap on the ocean, reflecting sunlight back into the atmosphere, keeping the algae contained and in check. When sea ice declines, large algal blooms are expected to increase.

Marine algae are essentially waterbound plants — they need sunlight and nutrients to multiply. During the winter, they’re mostly inactive because the Arctic is dark, at times for 24 hours a day. This inactivity allows nutrient to build up during the winter months. Then, as sea ice disappears in spring and summer months, sunlight can penetrate into the water, allowing algae to flourish to levels never before seen.

Without that cap, Arctic seas experiencing some of the highest algal production rates in the world, Frey said. She pointed to a 930-mile-long algal bloom — longer than California — recorded off the eastern coast of Greenland in May 2019. Based on observations from NASA’s Aqua satellite, the biomass in this bloom was 18 times higher than any event on record and occurred one month earlier than the typical peak for algal blooms. Earlier blooms suggest larger sea-choking events lasting for longer portions of the year.

Total mass change (in gigatonnes or billions of metric tons) of the Greenland ice sheet between April 2002 and April 2019. Infographic by Megan McGrew

Total mass change (in gigatonnes or billions of metric tons) of the Greenland ice sheet between April 2002 and April 2019. Infographic by Megan McGrew

Another issue highlighted in the report is the age of the sea ice, which is becoming younger and younger as the years pass. In 1985, old ice — chunks that have been frozen continuously for more than four years — accounted for 33 percent of sea ice in the Arctic ocean.

“Now, it’s just 1 percent. There’s just this little sliver of this old ice remaining,” said Erich Osterberg, a climatologist at Dartmouth College. That decline is noteworthy because older sea ice is much thicker and harder to melt. “Right now, the vast majority of the sea ice is first-year ice. It’s new ice, about 70 percent of it.”

As sea ice vanishes, it allows ocean water to warm, which in turn increases air temperatures and imperils other forms of frozen water.

Greenland, where Osterberg conducts much of his research, is home to the second-largest ice sheet on the planet — and it is disappearing. The Arctic Report Card shows that roughly 95 percent of the Greenland ice sheet melted at some point in 2019, and the magnitude of ice loss rivaled 2012 as the worst year on record. From 2002 to 2019, Greenland’s ice sheet lost 267 billion metric tons per year, on average.

“Two hundred sixty-seven billion tons of ice is really hard to put into context, but you could start by imagining a herd of elephants charging into the ocean from Greenland,” Osterberg said. “If you imagine that, we’re talking about 2,000 elephants charging into the ocean every second. That’s how much mass is going from Greenland into the ocean.”

These melts appear to be happening faster along the edges of the ice sheet, which speak to other disparities occurring across the Arctic region. Some parts of the Arctic are simply warming faster and faring worse than others from year to year. For example, snow cover over the North American Arctic was significantly lower than that of Eurasian portions, which remained normal last year.

A frozen beach on the Bering Sea coast is seen near the last stretch mushers must pass before the finish line of the Iditarod dog sled race in Nome, Alaska, March 11, 2014. The Bering Sea is experiencing the most dramatic changes in the Arctic. Photo by REUTERS/Nathaniel Wilder

A frozen beach on the Bering Sea coast is seen near the last stretch mushers must pass before the finish line of the Iditarod dog sled race in Nome, Alaska, March 11, 2014. The Bering Sea is experiencing some of the most dramatic changes in the Arctic. Photo by REUTERS/Nathaniel Wilder

The way that permafrost — perennially frozen ground — appears to be thawing may spell ill tidings for atmospheric levels of greenhouse gases. Permafrost holds the corpses of plants, animals and microbes that died in Arctic and boreal habitats over hundreds of thousands of years.

That’s a huge cache of carbon, namely along the southern borders of the Arctic and ranging from 1,460 to 1,600 billion metric tons, currently locked in the ground. If fully released, this permafrost carbon may accelerate climate change faster than currently predicted. And this year’s Arctic Report card spotlights how those gases are already leaking — to the tune of about half a billion metric tons (or 1.1 trillion pounds)–into the atmosphere.

“We’re not really accounting for this extra carbon coming out of the Arctic,” said Ted Schuur, an ecosystem scientist at Northern Arizona University who wrote the report card’s essay on permafrost. For comparison, humans burn enough fossil fuels each year to release about 10 billion metric tons of carbon.

While Arctic communities may be suffering the most now, elsewhere is starting to feel the effects, too — as the warming air disrupts weather patterns, throws off the polar jet stream and causes summer heat waves and winter cold snaps across much of North America and Europe.

“Things that we see happen in the Arctic are kind of foreshadowing what we expect elsewhere,” Schuur said.


Nsikan Akpan, digital science producer for PBS NewsHour and co-creator of the award-winning, NewsHour digital series ScienceScope.