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Antarctica’s Thwaites Glacier starting to collapse


Thwaites Glacier, Photo courtesy NASA.

New data means sea level may rise more — and sooner — than expected

Staff Report

FRISCO — Antarctica’s massive, fast-moving Thwaites Glacier is probably going to be history in a couple of centuries, leading to a two-foot rise in global sea level, according to a new study funded by the National Science Foundation.

The glacier is a key piece in the global sea level puzzle, acting as an ice dam, stabilizing and regulating movement toward the sea of the massive West Antarctic Ice Sheet. The ice sheet contains enough ice to cause another 3 to 4 meters (10 to 13 feet) of global sea level rise. Continue reading

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Climate: West Antarctic Ice Sheet is in trouble

Meltdown is inevitable …


New findings require upward revision of sea level rise estimates. bberwyn photo.

By Summit Voice

FRISCO — Scientists say it’s only a matter of time before a huge chunk of the West Antarctic Ice Sheet melts into the ocean, potentially raising sea level around the world by several feet.

“The collapse of this sector of West Antarctica appears to be unstoppable,” said glaciologist Eric Rignot, a UC Irvine Earth system science professor who is also with NASA’s Jet Propulsion Laboratory. “The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating parts of the glaciers. At this point, the end appears to be inevitable.” Continue reading

UK scientists seek to pinpoint West Antarctic ice loss

Robots, seal-mounted instruments and remote-operated subs part of ambitious project to study Pine Island, Thaite glaciers

West Antarctic ice sheets

West Antarctic ice sheets are melting fast, and scientists want to know why. bberwyn photo

By Summit Voice

FRISCO — With this year’s Antarctic research season starting to ramp up, a key focus is taking a closer look at ice sheets on the western side of the continent, where rapid ice loss from the Pine Island and Thwaite glaciers could affect sea level worldwide.

A team of researchers led by the British Antarctic Survey aims to discover what’s causing the recent rapid ice loss, and whether this loss will continue to increase or slow down. Continue reading

Climate: Does El Niño drive West Antarctic warming?

Ice cores suggest current climate is in the natural range of variability


Climate scientists track Antarctic changes, Bob Berwyn photo.

By Summit Voice

FRISCO — Ice cores from West Antarctica spanning the last 2,000 years suggest that recent warming and glacier loss in the region is comparable to other warm periods during that span.

Most of the recent warming may be related to powerful El Niño phases in the tropical Pacific in the 1990s, said University of Washington researcher Eric Steig. The ice core record shows similar temperature spikes in the 1830s and 1940s, he said, adding that the recent warming  cannot be attributed with confidence to human-caused global warming.

Steig built on previous research showing that rapid thinning of Antarctic glaciers was accompanied by rapid warming and changes in atmospheric circulation near the coast. The new study suggests that the 1990s were not all that different from some of those earlier warm spells. Continue reading

New ice core data from Greenland offers chilling clues about the direction of Earth’s climate

‘Our kids and grandkids are definitely going to look back and shake their heads at the inaction of this country’s generation’


For several days in July 2012, the surface of the Greenland ice sheet melted over a larger area than at any time in more than 30 years of satellite observations. An estimated 97 percent of the ice sheet surface had thawed by July 12, with satellite data providing a picture of an extreme melt event about which scientists are very confident. Graphic courtest Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory.

By Summit Voice

FRISCO — Last summer’s unusual melting at the surface of Greenland’s ice cap has a historic precedent, but you have to go back more than 100,000 years, to an extremely warm interglacial period of Earth’s history, to find it, according to an international science team’s  analysis of ice core samples spanning millennia of climate history.

The new study, published this week in Nature, offers clues about where the planet is headed in terms of increasing greenhouse gases and rising temperatures, according to CU-Boulder ice core expert Jim White — another researcher whose detailed knowledge of climate science has led him to advocate for reductions in greenhouse gas emissions.

“Unfortunately, we have reached a point where there is so much carbon dioxide in the atmosphere it’s going to be difficult for us to further limit our impact on the planet,” White said. “Our kids and grandkids are definitely going to look back and shake their heads at the inaction of this country’s generation. We are burning the lion’s share of oil and natural gas to benefit our lifestyle, and punting the responsibility for it.” Continue reading

Climate: Study suggests recent West Antarctic glacier changes are nearly unprecedented

Data to help refine sea level rise forecasts


West Antarctica‘s Pine Island Glacier. Photo courtesy European Space Agency.

By Summit Voice

FRISCO — After studying the paleoclimate record of West Antarctica, an international team of scientists say some of the recent observed changes in the Pine Island and Thwaites glaciers may well be exceptional and are unlikely to have happened more than three or four times in the last 10,000 years.

Radiocarbon dates of tiny fossilized marine animals found in Antarctica’s seabed sediments offer new clues about the recent rapid ice loss from the West Antarctic Ice Sheet and help scientists make better predictions about future sea-level rise.  This region of the icy continent is thought to be vulnerable to regional climate warming and changes in ocean circulation. Continue reading

Global warming research eyes ‘runaway’ ice melt

Sea level forecasts may be way off


Will there be runaway ice sheet melting? Bob Berwyn photo.

By Summit Voice

FRISCO — Most climate models are probably underestimating the rate of sea level rise expected during the next few decades, according to some of the latest research that tries to quantify how much ice may melt off the Greenland and Antarctica ice sheets.

A Dec. 26 update by James Hansen and Makiko Sato warns that melting of those ice sheets could increase sea level rise exponentially higher than most existing forecasts, potentially inundating coastal cities around the world with several feet of water by the end of the century.

The short paper discusses the linearity assumptions in most existing climate models and suggests that, if greenhouse gas emissions continue unchecked, “the climate forcing will be so large that non-linear ice sheet disintegration should be expected and multi- meter sea level rise not only possible but likely.” Continue reading

Global warming: Study suggests temperatures in West Antarctica rising much faster than previously estimated

New data fills gap in Antarctic climatology


A new evaluation of temperatures records from West Antarctica raises concerns about impacts to sea level rise. Bob Berwyn photo.

By Summit Voice

FRISCO — A new analysis of temperature records from a research station in West Antarctica suggests that temperatures in the remote region have climbed steeply in the last half-century, by as much as 4.3 degrees since 1958.

The findings, published in the most recent issue of Nature Geoscience, heighten concerns about the future contribution of Antarctica to sea level rise, because researchers say the West Antarctic Ice Sheet is especially sensitive to climate change.

Since the base of the ice sheet rests below sea level, it is vulnerable to direct contact with warm ocean water. Its melting currently contributes 0.3 mm to sea level rise each year—second to Greenland, whose contribution to sea level rise has been estimated as high as 0.7 mm per year, according to Ohio State University doctoral student Julien Nicolas. Continue reading

Climate: New clues for West Antarctic ice sheet melting

New data shows warm ocean currents melting the ice from below


Antarctic sea ice has expanded slightly in recent years, but the continental ice shelves are losing mass. Bob Berwyn photo.

By Summit Voice

FRISCO — New data from sensors in the Amundsen Sea suggest more strongly than ever that warm ocean currents are causing extensive ice loss from the West Antarctic Ice Sheet.

Ice in the area is melting faster than expected and could contribute significantly to sea level rise, but there’s been very little data from the region. The latest observations by oceanographers from the University of Gothenburg (Sweden) were recently published in the journal Nature Geoscience.

Previous research by the British Antarctic Survey showed that rising air temperatures in the region will break down a hydrological boundary of cold water, allowing warmer water to infiltrate beneath the ice. Continue reading

Climate: Arctic and Antarctic ice melt are accelerating

Greenland and Antarctica are now losing more than three times as much ice as they were in the 1990s

Antarctic sea ice may be growing, but ice sheets on the frozen continent’s edge are losing mass and contributing to sea-level rise. Bob Berwyn photo.

By Summit Voice

SUMMIT COUNTY — Climate scientists say they’re closer to pinpointing exactly how much of Greenland’s and Antarctica’s ice is melting, and after producing the most accurate assessment of ice losses to-date, a team of satellite experts say they’ve ended 20 years of uncertainty about how much that melting ice contributes to global sea level rise.

According to the landmark study, published on Nov. 30 in the journal Science, the that melting has contributed 11.1 millimeters to global sea levels since 1992. This amounts to 20 percent of all sea level rise during the survey period. About two thirds of the ice loss was from Greenland, and the remainder was from Antarctica.

Together, Greenland and Antarctica are now losing more than three times as much ice (equivalent to 0.95 mm of sea level rise per year) as they were in the 1990s (equivalent to 0.27 mm of sea level rise per year). The rate of melting increased dramatically in the late 1990s. Continue reading


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