Man-made Warming the Main Cause of Glacier Retreat -Study

Posted by Eric Haun
Thursday, August 14, 2014
Photo Credit: O. Baranova

Man-made greenhouse gas emissions have become the dominant cause of melting in glaciers from the Alps to the Andes that is raising world sea levels, a study said on Thursday.

Human emissions accounted for an estimated 69 percent of loss of ice from glaciers from 1991-2010, overtaking natural climate variations that had been the main driver of a retreat since the mid-19th century, researchers wrote in the journal Science.

Until now, scientists have struggled to quantify the impact of human behaviour on glaciers because the frozen rivers of ice take decades, perhaps centuries, to respond to rising temperatures and shifts in snow and rainfall.

The study published on Thursday used historical observations of glaciers around the world, except in Antarctica, twinned with computer models to simulate all factors that could explain the retreat. It found that natural variations were not enough on their own, meaning man-made greenhouse gases played an increasing role.

"This is more evidence of human influence on the climate," Ben Marzeion, of the University of Innsbruck in Austria and lead author of the study, told Reuters.

The scientists estimated that human influences accounted for only about 25 percent of glaciers' total retreat since 1850 - meaning that natural swings in the climate, such as changes in the sun's output, have long been dominant.

Little Ice Age
Many glaciers grew during a period known as the Little Ice Age from 1350 to 1850, perhaps caused by a natural decline in the sun's output or sun-dimming volcanic eruptions.

Michael Zemp, head of the World Glacier Monitoring Service at the University of Zurich, said snowfall declined after around 1850. Rising temperatures from about the 1890s, when wider burning of coal meant more greenhouse gases, hastened the thaw.

"The big majority of glaciers have been retreating over the past century," he told Reuters. "We even have an accelerated retreat in recent decades." Glaciers have also varied widely - many Alpine glaciers advanced in the 1970s and 1980s.

Thursday's study estimated that water from melting glaciers has contributed a total of 13.3 cms (5 inches) from 1851-2010 to rising sea levels. Without human influences the rise would still have been 9.9 cms (4 inches).

Zemp said that greenhouse gases already in the atmosphere meant that glacier retreat and related sea level rise would continue for decades, even if emissions were to stop now.

Melting glaciers, especially in the Himalayas, also supply water vital to millions of people. A Chinese newspaper said that Tibet was warmer over the past 50 years than at any time in the past 2,000.

Pinning down a human influence on temperatures has been easier. A U.N. scientific panel said last year that it was at least 95 percent probable that mankind was the main cause of higher surface temperatures since 1950.

(By Alister Doyle, Environment Correspondent; Reporting by Alister Doyle; Editing by Ruth Pitchford)

Maritime Reporter May 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Environmental

Korean Register Opens Green-ship Certification Center

The Korean Register informs it has formally opened the Green-ship Equipment Test Certification Center in Gunsan, Jeonbuk, Korea.   This large-scale facility will

DNV GL Names Remi Eriksen Group CEO

Remi Eriksen has been appointed as the DNV GL Group’s new president and CEO, succeeding Henrik O. Madsen, who will retire August 1. The DNV GL board of directors

LNG Vessel with Wartsila Integrated Solutions Delivered to Evergas

The first in a series of 27,500 cbm 'Dragon' class vessels ordered by Evergas, a world renowned owner and operator of seaborne petrochemical and liquid gas transport vessels,

News

Israeli Port Workers Defy Court Order to Continue Strike

Striking Israeli dockworkers defied a court order on Thursday and shut down the country's two main seaports for a second day in protest at the creation of two new foreign-run ports.

New Ferry Safety Initiative from RINA

Italy-based classification society RINA informs it has launched a ferry safety initiative.    The Asset Integrity Management scheme for ro-pax ferries covers fire risk mitigation,

Korean Register Opens Green-ship Certification Center

The Korean Register informs it has formally opened the Green-ship Equipment Test Certification Center in Gunsan, Jeonbuk, Korea.   This large-scale facility will

Marine Science

VIKING’s Top Safety Offerings at Nor-Shipping

Marine safety equipment leader VIKING Life-Saving Equipment will appear in force at Nor-Shipping 2015, displaying both innovative products and services that

US Forecaster Predicts Below-average Atlantic Hurricane Season

The Atlantic Ocean will see a below-average number of hurricanes this season due to cooler seas and a strong El Niño effect, the U.S. government weather forecaster announced on Wednesday.

UNOLS Seeks Fleet Improvement Committee Chair

The University-National Oceanographic Laboratory System (UNOLS) informs it is seeking nominations to fill a Fleet Improvement Committee (FIC) Chair position.   The position,

Arctic Operations

Keel Laid for Russia’s Next Generation Icebreaker

The world’s biggest nuclear-powered icebreaker keel laying ceremony took place of at the Baltic Shipyard on 26 May 2015. Heads of Atomfflot, the Baltic Shipyard

US Senators Want a Stop to Arctic Drilling

Eighteen U. S. senators have urged the Obama’s administration to halt Shell’s Arctic drilling plans saying that it is an unacceptable and irresponsible decision, says a report in Reuters.

Arctic Sea Ice Decline

Sea ice in the Arctic Ocean is at its lowest May level since records began in the 1980s, says Al Jazeera.    The lowest levels in the history of Arctic sea ice

Offshore Energy

U.S.: Stronger Response in South China Sea Needed

By releasing video of Beijing's island reclamation work and considering more assertive maritime actions, the United States is signaling a tougher stance over the

Fugro Extends Contract with McDermott

Fugro has been awarded a three-year extension to its existing contracts with McDermott Middle East, Inc. The contract covers the provision of survey, positioning,

First Damen Twin Axe for Offshore O&G

To develop its large fleet, Groen Offshore, Guard & Support has selected the first Damen Twin Axe Fast Crew Supplier 2610 to be customised with Offshore Oil & Gas standby capabilities.

 
 
Maritime Contracts Maritime Security Navigation Offshore Oil Pipelines Port Authority Salvage Ship Repair Shipbuilding / Vessel Construction Sonar
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.2276 sec (4 req/sec)