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

Posted on January 19, 2013 by Bob Berwyn

Data to help refine sea level rise forecasts

;lk

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. (more…)

Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: , , , , , , , | 3 Comments »

Climate: ‘Today’s flood is tomorrow’s high tide … ‘

Posted on January 18, 2013 by Bob Berwyn

‘The ocean is rising and it’s going to keep rising for quite some time’

dfgh

A NOAA aerial photo shows damage caused by superstorm Sandy along the New Jersey shoreline. Click on the photo to see before and after images on the NASA EO website.

By Bob Berwyn

FRISCO — What until recently was a mostly academic discussion about sea level rise is starting to hit home — literally —as Americans watch devastating storms like Katrina, Irene and Sandy engulf cities and fundamentally alter the shape of coastal areas.

“What is very clear is, the ocean is rising and it’s going to keep rising for quite some time. The difference from last time is, now, there are a lot of people living on the coast,” said Margaret Davidson, acting director of NOAA’s Office of Ocean and Coastal Resource Management. Davidson’s powerpoint presentation is online here, and a video of her presentation should also be posted at the same place soon.

The consequences of rising sea level are likely to be enormous, given that the majority of the country’s population lives along coastlines, and those coastal cities generate a huge percentage of the country’s economic wealth.

“How do we begin to think about that? We’ve never had to think about relocating large populations,” Davidson said, addressing an audience of broadcast meteorologists and climate scientists during the annual Glen Gerberg Weather and Climate Summit in Breckenridge. (more…)

Filed under: climate and weather, Environment, global warming | Tagged: , , , , , , , , , , | 1 Comment »

Global warming: Sea level rise threatens Hawaii biodiversity

Posted on December 17, 2012 by Bob Berwyn
sdfg

Pelagic birds do need a bit of land, and some nesting areas in Hawaii may be threatened. Bob Berwyn photo.

USGS study says sea bird rookery in outlying Hawaiian Islands at risk

By Summit Voice

SUMMIT COUNTY — Sea level rise could threaten the breeding areas of numerous sea bird breeding areas in the northwestern Hawaiian Islands, according to a new U.S. Geological Survey study that analyzed the combined effects sea-level rise and wave action.

Most climate change models predict a 1-meter rise in global sea level by 2100, with larger increases possible in parts of the Pacific Ocean. Those rising sea levels may inundate low-lying islands across the globe, placing island biodiversity at risk. (more…)

Filed under: biodiversity, climate and weather, Environment, global warming | Tagged: , , , , , , | Leave a Comment »

Climate: More snow in Antarctica will speed up ice loss

Posted on December 13, 2012 by Bob Berwyn

Antarctica ice-loss rate about equal to Greenland’s

sdfg

Increasing snowfall in Antarctica could — almost paradoxically — speed up the loss of ice mass. Bob Berwyn photo.

By Summit Voice

FRISCO — German researchers say they’ve placed another piece of the Antarctic climate puzzle by calculating how heavier snowfall on the frozen continent is likely to increase future ice discharges from the continental ice sheets.

Their study, published this week in Nature, shows that a lot of the Antarctic ice gain due to increased snowfall is countered by an acceleration of ice-flow to the ocean. Thus, Antarctica’s contribution to global sea-level rise is probably greater than estimated, the team of authors from the Potsdam Institute for Climate Impact Research concluded.

The research team’s ensemble of ice-physics simulations shows that future ice discharge will increased up to three times because of additional precipitation in Antarctica under global warming. During the last decade, the Antarctic ice-sheet has lost volume at a rate comparable to that of Greenland. (more…)

Filed under: Antarctica, climate and weather, Environment, global warming, snow | Tagged: , , , , | 2 Comments »

Climate: Arctic and Antarctic ice melt are accelerating

Posted on November 30, 2012 by Bob Berwyn

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. (more…)

Filed under: Antarctica, Arctic, climate and weather, Environment, global warming | Tagged: , , , , , , , , | Leave a Comment »

Global warming: Sea level rising much faster than forecast

Posted on November 28, 2012 by Bob Berwyn

Observational data is piling up and showing that sea level rise is exceeding the rate predicted by the IPCC

Glaciers and ice caps are melting, and sea level is rising even faster than forecast by the IPCC. Photos courtesy NASA. (Click the image for more information.)

By Summit Voice

SUMMIT COUNTY — Sea levels during the past two decades are rising 60 percent faster than the general estimates made by the IPCC, according to new research published this week in the journal Environmental Research Letters.

The scientists with the Potsdam Institute for Climate Impact Research, Tempo Analytics and Laboratoire d’Etudes en Géophysique et Océanographie Spatiales said that, while temperature rises appear to be consistent with the projections made in the IPCC’s fourth assessment report , satellite measurements show that sea-levels are rising at a rate of 3.2 mm a year compared to the best estimate of 2 mm a year in the report.

“This study shows once again that the IPCC is far from alarmist, but in fact has under-estimated the problem of climate change,” said lead author Stefan Rahmstorf. “That applies not just for sea-level rise, but also to extreme events and the Arctic sea-ice loss.” (more…)

Filed under: climate and weather, Environment, global warming | Tagged: , , , , , , , | 6 Comments »

Alaska’s Columbia Glacier may stop retreating by 2020

Posted on November 27, 2012 by Bob Berwyn

New modeling may help generate more accurate predictions of sea level rise

An iceberg from Alaska’s Columbia Glacier floats in Prince William Sound. Photo by Kim Fenske.

By Summit Voice

SUMMIT COUNTY — Alaska’s Columbia Glacier — a poster child for the impacts of global warming — is likely to stop receding around 2020, when the terminus of the glacier retreats into water shallow enough to provide a stable position through 2100 by slowing the rate of iceberg production.

The Columbia Glacier is a large (425 square miles), multi-branched glacier in south-central Alaska that flows mostly south out of the Chugach Mountains to its tidewater terminus in Prince William Sound.

The new study by Boulder-based University of Colorado scientists with the Cooperative Institute for Research in Environmental Sciences shows that a single glacier’s contribution to sea level rise can “turn on” and “turn off” quite rapidly, over a couple of years, with the precise timing of the life cycle being difficult to forecast. (more…)

Filed under: climate and weather, Environment, global warming | Tagged: , , , , , | 1 Comment »

Climate: Groundwater another factor in coastal flooding

Posted on November 12, 2012 by Bob Berwyn

Coastal and island communities must consider groundwater as a potential multiplier when planning for rising sea levels. Image courtesy NASA.

New study sees groundwater as doubling the amount of flooding in some areas

By Summit Voice

FRISCO — Some coastal communities may face a double whammy when it comes to climate-related flooding during the next few decades. Along with rising sea levels, there’s also the overlooked threat of inundation from groundwater sources, according to a new research done by scientists with the University of Hawaii at Manoa.

The study, published in the journal Nature Climate Change, shows that the flooded area in urban Honolulu, Hawaii, including groundwater inundation, is more than twice the area of marine inundation alone — Specifically, a 1-meter rise in sea level would inundate 10 percent of a 1-kilometer wide urbanized area along the shoreline of southern Oahu; 58 percent of the total flooded area would be due to groundwater inundation. (more…)

Filed under: climate and weather, Environment, global warming | Tagged: , , , , | Leave a Comment »

Global warming: Sea level rising faster than expected

Posted on November 5, 2012 by Bob Berwyn

Climate feedback loops at play in accelerated rate

This map by Emanuel Soeding, of Christian-Albrechts University, uses NOAA data to show possible impacts of sea level rise to the U.S. Coast.

By Summit Voice

FRISCO — Sea level rise is one of the most obvious signs of global warming, but climate scientists have been trying to figure out why the oceans are expanding faster than most models predict. The 2007 IPCC report forecast global sea level to rise between0.2 and 0.5 meters by the end of the century, but with the rate accelerating, that could increase to as much as 1 meter.

Sea levels are rising faster than expected from global warming, and University of Colorado geologist Bill Hay has a good idea why. The last official IPCC report in 2007 projected a global sea level rise between 0.2 and 0.5 meters by the year 2100. But current sea-level rise measurements meet or exceed the high end of that range and suggest a rise of one meter or more by the end of the century.

“What’s missing from the models used to forecast sea-level rise are critical feedbacks that speed everything up,” said University of Colorado geologist Bill Hay, explaining that the models may not be accurately accounting for feedbacks from Arctic sea ice, the Greenland ice cap, and even soil moisture and groundwater mining. (more…)

Filed under: climate and weather, Environment, global warming | Tagged: , , , , , | 1 Comment »

Climate: Discussions raging on possible links between global warming and superstorm Sandy

Posted on October 31, 2012 by Bob Berwyn

Hurricane Sandy bearing down on the East Coast. Satellite image courtesy NOAA.

Record-breaking storm spurs more public awareness about the potential for more frequent extreme weather events

By Bob Berwyn

SUMMIT COUNTY — With several all-time weather records shattered and early estimates that Hurricane Sandy may cost the U.S. economy some $20 to $25 billion, it’s clear that the storm lived up to its billing. Along with the cleanup, there’s also a raging debate about whether global warming was a factor in the storm’s development and path.

On the one side, environmental activists seeking to limit heat-trapping greenhouse gases have jumped on the so-called super storm as an opportunity to tout their cause. On the other side, global warming deniers and others have pulled out timeworn statistics about past hurricanes that supposedly were equally as strong.

The arguments at the extreme sides of the spectrum don’t ring true. Of course, there is no way to scientifically prove that increases in air and ocean temps directly contributed to this storm. There’s still so much natural variability in nature that you just can’t establish a causal link. (more…)

Filed under: climate and weather, Environment, global warming, tropical storms and hurricanes | Tagged: , , , , , , , , | 1 Comment »

« Previous Page — Next Page »
Follow

Get every new post delivered to your Inbox.

Join 5,587 other followers