Tag: ICE

Polar ice, atmospheric water vapor biggest drivers of variation among climate models — ScienceDaily

Posted on by [email protected]_84

A Florida State University researcher is part of a team that has found varying projections on global warming trends put forth by climate change scientists can be explained by differing models’ predictions regarding ice loss and atmospheric water vapor.

The work will help climate scientists reconcile various models to improve their accuracy, said Florida State University Meteorology Professor Ming Cai, one of the authors of the study published in Nature Communications .

Climate scientists agree that the Earth’s surface temperature is warming, but the details of exactly where and by how much are less clear. A worst-case climate change scenario (known as the “Representative Concentration Pathway 8.5”) predicted a likely increase in average global temperatures of about 2.6 degrees Celsius to 4.8 degrees Celsius (or about 4.7 degrees Fahrenheit to 8.6 degrees Fahrenheit) by 2100.

“This uncertainty limits our ability to foresee the severity of the global warming impacts on

… Read More Read More

Ice discharge in the North Pacific set off series of climate events during last ice age — ScienceDaily

Posted on by [email protected]_84

Repeated catastrophic ice discharges from western North America into the North Pacific contributed to, and perhaps triggered, hemispheric-scale changes in the Earth’s climate during the last ice age, new research published online today in Science reveals.

The discovery provides new insight into the impact rapidly melting ice flowing into the North Pacific may have on the climate across the planet, said Maureen Walczak, a paleoclimatologist in Oregon State University’s College of Earth, Ocean, and Atmospheric Sciences and the study’s lead author.

“Understanding how the ocean has interacted with glacial ice in the past helps us predict what could happen next,” Walczak said.

The Cordilleran ice sheet once covered large portions of western North America from Alaska to Washington state and western Montana. Radiocarbon dating and analyses of the marine sediment record revealed that recurrent episodes of discharge from this ice sheet over the past 42,000 years were early events in

… Read More Read More

Ice Age manatees may have called Texas home — ScienceDaily

Posted on by [email protected]_84

Manatees don’t live year-round in Texas, but these gentle, slow-moving sea cows are known to occasionally visit, swimming in for a “summer vacation” from Florida and Mexico and returning to warmer waters for the winter.

Research led by The University of Texas at Austin has found fossil evidence for manatees along the Texas coast dating back to the most recent ice age. The discovery raises questions about whether manatees have been making the visit for thousands of years, or if an ancient population of ice age manatees once called Texas home somewhere between 11,000 and 240,000 years ago.

The findings were published in Palaeontologia Electronica.

“This was an unexpected thing for me because I don’t think about manatees being on the Texas coast today,” said lead author Christopher Bell, a professor at the UT Jackson School of Geosciences. “But they’re here. They’re just not well known.”

The paper co-authors

… Read More Read More

Greenland is on track to lose ice faster than in any century over 12,000 years — ScienceDaily

Posted on by [email protected]_84

If human societies don’t sharply curb emissions of greenhouse gases, Greenland’s rate of ice loss this century is likely to greatly outpace that of any century over the past 12,000 years, a new study concludes.

The research will be published on Sept. 30 in the journal Nature. The study employs ice sheet modeling to understand the past, present and future of the Greenland Ice Sheet. Scientists used new, detailed reconstructions of ancient climate to drive the model, and validated the model against real-world measurements of the ice sheet’s contemporary and ancient size.

The findings place the ice sheet’s modern decline in historical context, highlighting just how extreme and unusual projected losses for the 21st century could be, researchers say.

“Basically, we’ve altered our planet so much that the rates of ice sheet melt this century are on pace to be greater than anything we’ve seen under natural variability of

… Read More Read More

Greenland ice loss worst in 12,000 years

Posted on by [email protected]_84

Ice loss from Greenland’s massive ice sheet will cause sea levels to rise more during the 21st century than they have during any 100-year period in the last 12,000 years, even if global warming is held in check, scientists said Wednesday.

The study — based on ice core data and models and published in the journal Nature — is the first to painstakingly reconstruct Greenland’s ice loss record over the entire course of the Holocene, the geological epoch that has allowed civilisation to flourish.

It found that if greenhouse gas emissions continue unabated, the kilometres-thick ice block will shed some 36 trillion tonnes of mass from 2000 to 2100, enough to lift the global ocean waterline by 10 centimetres.

Until the late 1990s, Greenland’s ice sheet was roughly in balance, gaining as much mass through snowfall as it lost in summer from crumbling glaciers and melt-off.

But accelerating climate change

… Read More Read More

Geologists glean insights about how Earth went from a hothouse to an ice age, and what that may mean for the future — ScienceDaily

Posted on by [email protected]_84

Usually, talk of carbon sequestration focuses on plants: forests storing carbon in the trunks of massive trees, algae blooming and sinking to the seabed, or perhaps peatlands locking carbon away for tens of thousands of years.

While it’s true that plants take up large amounts of carbon from the atmosphere, the rocks themselves mediate a great deal of the carbon cycle over geological timescales. Processes like volcano eruptions, mountain building and erosion are responsible for moving carbon through Earth’s atmosphere, surface and mantle.

In March 2019, a team led by UC Santa Barbara’s Francis Macdonald published a study proposing that tectonic activity in the tropics, and subsequent chemical weathering by the abundant rainfall, could account for the majority of carbon capture over million-year timeframes.

Now, Macdonald, doctoral student Eliel Anttila and their collaborators have applied their new model to the emergence of the Southeast Asian archipelago — comprising New Guinea,

… Read More Read More

The Technology 202: Activists slam Palantir for its work with ICE ahead of market debut

Posted on by [email protected]_84

But activist groups and human rights watchdogs say that the company’s track record of working with Immigration and Customs Enforcement and countries with questionable human rights records makes it a bad investment. They spent the last week protesting online and in-person to highlight concerns to investors ahead of the public listing. 

“There is a high risk that Palantir is contributing to human rights violations of asylum-seekers and migrants through the ways the company’s technology facilitates ICE operations,” Amnesty International said in a report released yesterday that accused Palantir of failing to guarantee its software isn’t being used to aid in human rights abuses and racial profiling against migrants. Palantir, which declined to comment for this piece citing its “quiet period” running up to the public listing, has said its software is not used for raids or deportations. 

Co-founded by Peter Thiel, a prominent donor to President Trump, the company has

… Read More Read More

Throwing a warm sheet over our understanding of ice and climate

Posted on by [email protected]_84

antarctica
Credit: Pixabay/CC0 Public Domain

Temperatures at Earth’s highest latitudes were nearly as warm after Antarctica’s polar ice sheets developed as they were prior to glaciation, according to a new study led by Yale University. The finding upends most scientists’ basic understanding of how ice and climate develop over long stretches of time.


The study, based on a reconstruction of global surface temperatures, gives researchers a better understanding of a key moment in Earth’s climate history—when it transitioned from a “greenhouse” state to an “icehouse” state. The study appears in the journal Proceedings of the National Academy of Sciences the week of Sept. 28.

“This work fills in an important, largely unwritten chapter in Earth’s surface temperature history,” said Pincelli Hull, assistant professor of earth and planetary studies at Yale, and senior author of the study.

Charlotte O’Brien, a former Yale Institute for Biospheric Studies (YIBS) Donnelley Postdoctoral Fellow who is

… Read More Read More

Palantir’s ICE Contracts ‘Raise Human Rights Concerns’, Report Warns As Firm Prepares To Go Public

Posted on by [email protected]_84

With Palantir Technologies Inc. prepared to go public this week through a direct listing on the New York Stock Exchange, Amnesty International has released a report condemning the data-mining firm over “human rights concerns” raised by its contracts with the U.S. Immigration and Customs Enforcement (ICE) agency.

Titled Failing to Do Right: The Urgent Need for Palantir to Respect Human Rights, the report, which was released on Monday, concludes that Palantir is “failing to conduct human rights due diligence around its contracts with ICE,” a press release from Amnesty states.

As a result, the organization states, the company, which was co-founded by Peter Thiel, runs a “high risk” of “contributing to human rights violations of asylum-seekers and migrants through the ways

… Read More Read More

Light-loving algae grow under ice during the dark Arctic winter

Posted on by [email protected]_84

Each winter, Baffin Bay freezes over as polar darkness descends over the top of the world.

Come spring, phytoplankton will bloom in these cold waters between Greenland and Canada, bolstering a bustling ecosystem of beluga whales and narwhals (SN: 4/8/20). But scientists have long assumed that the photosynthetic algae remain largely dormant in winter, blocked off from light by thick sea ice and snow.

New research challenges that assumption, however, finding that phytoplankton under the bay’s ice start growing as early as February, when the sun barely blips above the Arctic’s horizon.

Achim Randelhoff, an oceanographer at Université Laval in Quebec City, and colleagues deployed autonomous submersible floats in Baffin Bay that can measure photosynthetic activity and algae concentrations underwater.

In February, when light was barely detectable

… Read More Read More