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Climate: Antarctic ice melting faster than ever

New satellite data details rate of melting

Yes, there is still lots of ice in Antarctica, but it's melting faster than ever. bberwyn photo.

Yes, there is still lots of ice in Antarctica, but it’s melting faster than ever. bberwyn photo.

Staff Report

FRISCO — Yet another major study — the third within a week — confirms that the Antarctic ice sheets are going to big factors in the rise in sea level during the next few decades.

Led by scientists from the University of Leeds, the study shows that Antarctica is losing about 159 billion tons of ice each year — twice as much as during the last detailed survey. The latest assessment relied on detailed measurements of ice sheet elevation change from data collected by the European Space Agency’s CryoSat-2 satellite mission, which carries an altimeter specially designed for this task. Continue reading

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Climate: Annual sea-level cycles intensifying along eastern Gulf Coast

Higher summer spikes could mean more destructive storm surges

Researchers have documented changes in the annual cycle of sea level changes along the Florida Gulf Coast. bberwyn photo.

Researchers have documented changes in the annual cycle of sea level changes along the Florida Gulf Coast. bberwyn photo.

By Summit Voice

FRISCO — Annual sea level fluctuations have been intensifying along parts of the Gulf Coast, raising concerns about more hurricane flooding and impacts to delicate coastal ecosystems in the region.

There have always been seasonal fluctuations in sea level, which rise in summer and fall in winter. But a new study shows that, from the Florida Keys to southern Alabama, those cycles have amplified in the past 20 years.

The additional summer sea level rise during the past two decades means storm surges can rise higher than previously thought, according to Thomas Wahl, a postdoctoral researcher from the University of Siegen in Germany who is working at the University of South Florida in St. Petersburg and lead author of the study. Continue reading

Global warming: Island biodiversity at risk

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These atolls in the Maldives are only about 1 meter above sea level. Learn more at this NASA Earth Observatory website.

More than 10,000 islands will be completely inundated by the end of the century

By Summit Voice

FRISCO — Low-lying tropical islands harboring a disproportionately high percentage of the world’s biodiversity are also vulnerable to rising seas. With most climate models conservatively estimating that sea level will rise between 2 and six feet by the end of the century, some biodiversity hotspots could be completely lost, according to a new study from researchers with the University of Paris Sud.

“Losses of insular habitats will … be relatively important in the future, probably leading to a major impoverishment of insular biodiversity,” said lead author Dr. C. Bellard. ” Given the implications of these results, decision-makers are required to define island conservation priorities that accounts for sea level rise following climate change,” he added. Continue reading

Climate: Grant program aims to boost coastal resilience with restoration of wetlands, marshes and beaches

Hurricane Sandy

Hurricane Sandy lashes the Northeast Coast in October. 2012. Image courtesy NASA.

Enhanced natural features eyed as buffers to coastal storm impacts

By Summit Voice

FRISCO — The U.S. Department of Interior plans to help protect the Atlantic Coast from future storms with a competitive $100 million grant program, eying projects that will restore coastal marshes, beaches and wetlands that can buffer storm impacts.

“By stabilizing marshes and beaches, restoring wetlands, and improving the resilience of coastal areas, we not only create opportunities for people to connect with nature and support jobs through increased outdoor recreation, but we can also provide an effective buffer that protects local communities from powerful storm surges and devastating floods when a storm like Sandy hits,” said Interior Secretary Sally Jewell.

“In cooperation with the National Fish and Wildlife Foundation, this competitive grant program will fund innovative projects by States, local communities, tribes, non-profit organizations and other partners to rebuild, restore, and research these natural areas along the Atlantic Coast,” Jewell said. 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: Study raises new questions about future of East Antarctic ice sheet

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The future of Antarctic ice sheets is a key question in climate change research.

By Summit Voice

FRISCO — The world’s largest ice sheet could be more vulnerable to the effects of climate change than previously thought, according to new research from Durham University. Using declassified spy satellite images, the researchers created a long-term record of changes in the ice sheet’s outlet glaciers.

The mapping, spanning 50 years, from 1963 to 2012, shows that the glaciers underwent rapid and synchronized periods of advance and retreat which coincided with cooling and warming. Large parts of the ice sheet, which reaches thicknesses of more than 4 kilometers, could be more susceptible to changes in air temperatures and sea-ice than previously believed. Continue reading

Climate: What if Arctic sea ice doesn’t form in winter?

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Arctic sea ice is on a downward spiral. Visit this NASA Earth Observatory website for information on this image.

New models look at year-round ice-free conditions to find parallels with Pliocene epoch

By Summit Voice

FRISCO — As atmospheric concentrations of carbon dioxide start to hover around 400 parts per million, climate scientists have been looking back about 3 to 5 million years, to the Pliocene Epoch — the last time heat-trapping greenhouse gases were at a similar level.

But temperatures during the Pliocene were about 3.5 to 9 degrees Fahrenheit warmer than today and the sea level was 65 to 80 feet higher. Until now, scientists have assumed that there’s a time lag between atmospheric CO2 levels and the subsequent temperature increases that melt ice and drive ocean levels up. Continue reading

Climate: How stable is the East Antarctica ice sheet?

New research suggests significant melting during Pliocene era, when CO2 levels and temps were comparable to levels projected by 2100

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Parts of the Antarctic ice sheets may not be as stable in the face of climate change as previously believed. Bob Berwyn photo.

By Summit Voice

FRISCO — The biggest ice sheet in the world may be more susceptible to a warming climate than previously believed.

New evidence garnered from mud deposits suggests that the East Antarctica Ice Sheet may have experiences significant melting about 5 million years ago — enough to raise sea level by about 60 feet worldwide, according to researchers from Imperial College London.

The study, published last week in  the journal Nature Geoscience, shows that there was repeated melting between five and three million years ago, during a geological period called Pliocene Epoch, when atmospheric CO2 levels were similar to today’s and temperatures comparable to what’s being projected by the end of this century. Continue reading

Climate: Ocean melting Antarctic ice shelves from beneath

Study says iceberg calving a smaller factor in ongoing ice loss

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Pinpointing the rate of ice melt in Antarctica will help fine-tune future sea level rise projections. Bob Berwyn photo.

By Summit Voice

SUMMIT COUNTY — Supporting the conclusions of several previous research efforts, a new study published this week in Science provides additional evidence that Antarctica’s ice shelves are melting from beneath. Warmer ocean waters — not icebergs calving into the sea — are responsible for most of the continent’s ice loss, the study by UC Irvine scientists and others has found.

The first comprehensive survey of all Antarctic ice shelves discovered that basal melt, or ice dissolving from underneath, accounted for 55 percent of shelf loss from 2003 to 2008 — a rate much higher than previously thought. Ice shelves, floating extensions of glaciers, fringe 75 percent of the vast, frozen continent.

The findings will help scientists improve projections of how Antarctica, which holds about 60 percent of the planet’s freshwater locked in its massive ice sheet, will respond to a warming ocean and contribute to sea level rise. Continue reading

New website to report on Greenland’s melting ice cap

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The Greenland ice sheet is becoming less reflective, according to NASA measurements.

Portal to feature daily updates on melting episodes and analysis of conditions

By Bob Berwyn

SUMMIT COUNTY — Climate scientists have long been keeping a close watch on Greenland’s ice sheet, a key indicator of global warming impacts. This month, the National Snow and Ice Data Center launched a new website to help track the changes on an continual basis.

The new site, Greenland Today, will present images of the widespread melt on Greenland during 2012 and scientific commentary on the year’s record-breaking melt extent, which far exceeded all previous years of satellite monitoring, and led to significant amounts of ice loss for the year.

Satellite images updated daily, with a one-day lag and a daily melt image shows where the surface of the Greenland Ice Sheet experienced melt on that day.

“The Greenland melting last year was just tremendous … about 600 to 700 billion tons of ice melted and ran off,” said NSIDC glaciologist Ted Scambos, explaining that, as recently as the 1990s, scientists estimated the rate of melt at anywhere from zero to 30 billion tons. Just in the past few years, that number jumped dramatically, from 100 billion to 500 billion tons or more, Scambos said. Continue reading

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