Climate: National Parks face huge sea level threats

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Can the National Park Service protect coastal assets from rising sea levels? Photo courtesy U.S. Air Force.

Study says $40 billion in park assets at risk

Staff Report

FRISCO — Researchers are only a third of the way through their efforts to catalog how rising sea level threatens national parks, but they’ve already documented risks to more than $40 billion worth of park assets.

“Many coastal parks already deal with threats from sea level rise and from storms that damage roads, bridges, docks, water systems and parking lots,” National Park Service Director Jonathan B. Jarvis said in a prepared statement. “This infrastructure is essential to day-to-day park operations, but the historical and cultural resources such as lighthouses, fortifications and archaeological sites that visitors come to see are also at risk of damage or loss.” Continue reading

Climate: Alaska glaciers a big factor in sea level rise

Photograph of the calving terminus of Tyndall Glacier, located at the head of Taan Fiord, Icy Bay, Wrangell - St. Elias National Park, Alaska. Photo courtesy USGS.

Photograph of the calving terminus of Tyndall Glacier, located at the head of Taan Fiord, Icy Bay, Wrangell – St. Elias National Park, Alaska. Photo courtesy USGS.

New study helps quantify glacial meltdown

Staff Report

FRISCO — Global warming is melting Alaska’s glaciers so fast that the water would cover the entire state a foot deep every seven years, scientists report in a new study. The melting won’t slow down anytime soon and will be a major factor in global sea level rise, the researchers said.

“The Alaska region has long been considered a primary player in the global sea level budget, but the exact details on the drivers and mechanisms of Alaska glacier change have been stubbornly elusive,” said Chris Larsen, a research associate professor with the Geophysical Institute at the University of Alaska Fairbanks. Continue reading

Climate: Is this the Antarctic tipping point?

Study shows widespread, simultaneous ice shelf melting

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Satellite data shows sudden shift in ice shelf dynamics along the southern Antarctic Peninsula. @berwyn photo.

Staff Report

FRISCO — Along with studies showing dramatic changes in individual ice shelves in Antarctica, new research shows widespread changes in the region since 2009. Up until then, the Southern Antarctic Peninsula showed no signs of change.

But suddenly, multiple glaciers along a vast coastal expanse, measuring some 750km in length, suddenly started to shed ice into the ocean at a nearly constant rate of 60 cubic kilometers, or about 55 trillion liters of water, each year. This makes the region the second largest contributor to sea level rise in Antarctica and the ice loss shows no sign of waning. Continue reading

Global warming: Antarctic ice shelves have thinned 18 percent in the past two decades

Troubling signs of a major meltdown continue

It's not clear when the waters around Antarctica will no longer be able to support production of phytoplankton.

 Global warming is nibbling away at Antarctica’s ice sheets, which show declines of up to 18 percent in a new analysis of satellite data. bberwyn photo.

Staff Report

*More Summit Voice stories on global warming changes in Antarctica.

FRISCO — In the dry language of science, researchers this week said that some of Antarctica’s floating ice shelves have thinned by as much as 18 percent in just a couple of decades — a finding that provides “new insights on how the Antarctic ice sheet is responding to climate change.”

After analyzing 20 years of satellite data, the new NASA-supported study shows the ice volume decline is accelerating under a thickening blanket of greenhouse gases. Merging data from three overlapping missions, the study was able to show the trend over time rather than just offering a snapshot view of the ice.

“Eighteen percent over the course of 18 years is really a substantial change,” said Paolo. “Overall, we show not only the total ice shelf volume is decreasing, but we see an acceleration in the last decade.” said Scripps graduate student Fernando Paolo. Continue reading

Rising sea level to take big bite from Hawaii beaches

Study projects increasing rate of coastal erosion

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The Hawaiian Islands via NASA Earth Observatory.

Staff Report

FRISCO — As sea level rises, Hawaii’s beaches are on track to shrink by 20 to 40 feet during the next few decades, scientists announced in a new study.

“When we modeled future shoreline change with the increased rates of sea level rise projected under the IPCC’s “business as usual” scenario, we found that increased SLR causes an average 16 – 20 feet of additional shoreline retreat by 2050,” said lead author Tiffany Anderson, a post-doctoral researcher at the UHM School of Ocean and Earth Science and Technology. Continue reading

Climate: More melting ahead for East Antarctica glaciers

Seafloor channels sluicing warm ocean water toward base of East Antarctica’s Totten Glacier

Increasing concentrations of CO2 could turn this Antarctic beach into a tropical zone. Photo by Bob Berwyn.

Are Antarctica’s ice sheets near a global warming tipping point? bberwyn photo.

Staff Report

FRISCO — Scientists say they’re a step closer to understanding the extreme thinning of East Antarctica’s largest glacier, which contains enough ice to raise global sea level by about 11 feet.

Ocean gateways are sluicing warm water toward the base of the Totten Glacier near the shoreline, undercutting the icy anchors that slow the advance of the ice toward the sea, according to researchers with the University of Texas at Austin’s Institute for Geophysics, who outline their findings in the March 16 edition of the journal Nature Geoscience.

Similar findings from the region were reported by Australian scientists just a few weeks ago, and another study showed widespread thinning of ice in East Antarctica. Continue reading

How do Antarctica snowfall rates affect sea level rise?

New ice core analysis shows less of an ‘offset’ than most models currently project

Antarctica permafrost

Increasing snowfall in Antarctica will moderate the rate of global sea level rise — but not as much as previously thought. bberwyn photo.

Staff Report

FRISCO — Detailed ice core records from Antarctica show that snowfall over the frozen continent increased about 5 percent for each degree (Celsius) of warming as Earth emerged from the last ice age.

The findings confirm that the increased snowfall will slightly offset sea level rise, as suggested by other research — but not as much as previously thought. That means that some computer models may be underestimating the amount and rate of future sea level rise if they’re based on inaccurate assumptions. Continue reading

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