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 Today


The Maritime Industry's original and most viewed E-News Service

Maritime Reporter February 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Environmental

Maersk to Scrap Ships at India's Alang Beaches, NGO Dismayed

Maersk Line said on Friday it had chosen four shipbreaking yards along India's Alang beaches to handle an increase in vessels that need to be scrapped, to the dismay

Helsinki, Tyumen State Universities to form Arctic station

Within the framework of the international project Reeh, Tyumen State University in cooperation with the University of Helsinki are planning to create a unique Arctic observation stations.

Ice Condition 3 for Delaware Bay

The Captain of the Port (COTP), Delaware Bay is notifying mariners that Ice Condition 3 has been set for the Port which includes the Delaware Bay and River, the C&D Canal,

News

Nordana Sea Delivered to Symphony Shipping

After successful sea trials, M.V. Nordana Sea was delivered to Symphony Shipping on February 11, 2016. Constructed by builder Ferus-Smit in the Netherlands (yard number 419),

NATO Ships Arrive in Batumi

This morning, four NATO ships assigned to Standing NATO Mine Counter-Measures Group TWO (SNMCMG2) arrived in Batumi, Georgia for a scheduled visit in an effort

US Oil Drillers Cut Rigs to Least in 6 Years

U.S. energy firms this week cut oil rigs for an eighth week in a row to the lowest levels since January 2010, data showed on Friday, as energy firms continue to

Marine Science

OSD Designs Research Vessel for TORI

Offshore Ship Designers (OSD-IMT) has signed a new contract to design an IMT2001 Scientific Research Vessel for the Taiwanese Ocean Research Institute (TORI).    The

Update on Seagull Mobile apps for Crew

The Seagull mobile app for crew training status is set to revolutionise the way seafarers track their training records and receive critical safety alerts, by making

Royal Caribbean Ship Thrashed by Storm Returns on Wednesday

A Royal Caribbean cruise ship forced to turn back early after being battered by an Atlantic storm was expected to return to its New Jersey port at 9 p.m. on Wednesday (0200 GMT Thursday),

Arctic Operations

Helsinki, Tyumen State Universities to form Arctic station

Within the framework of the international project Reeh, Tyumen State University in cooperation with the University of Helsinki are planning to create a unique Arctic observation stations.

U.S. Okays ConocoPhillips Alaska LNG Exports

The U.S. Department of Energy approved ConocoPhillips' application to export about 40 billion cubic feet of natural gas from its Kenai liquefied natural gas export

IOCs Stress on OSV Fuel Management Performance

Growing insistence by international oil companies (IOCs) that oilfield contract vessels (OSVs) are fitted with fuel monitoring systems has prompted an upsurge in

Offshore Energy

US Oil Drillers Cut Rigs to Least in 6 Years

U.S. energy firms this week cut oil rigs for an eighth week in a row to the lowest levels since January 2010, data showed on Friday, as energy firms continue to

Eni, Exxon, Statoil Win Irish Offshore O&G Licences

The Irish government said on Thursday it had awarded oil and gas licences to companies including oil majors Eni, Exxon and Statoil , allowing them to explore for hydrocarbons off the coast of Ireland.

Neptune Awarded Kitan Contract

Neptune has been awarded an air diving services contract by Technip Oceania Pty Ltd (“Technip”) for the Kitan disconnection project. The project is offshore

 
 
Maritime Careers / Shipboard Positions Maritime Security Offshore Oil Pipelines Port Authority Salvage Ship Electronics Ship Repair Ship Simulators 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: 0.0869 sec (12 req/sec)