Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




CLIMATE SCIENCE
Is global heating hiding out in the oceans
by Staff Writers
New York NY (SPX) Nov 05, 2013


H. balthica fossils are painstakingly separated from grains of sand and then analyzed by mass spectrometers. Credit: (Rudy Diaz, Columbia University).

A recent slowdown in global warming has led some skeptics to renew their claims that industrial carbon emissions are not causing a century-long rise in Earth's surface temperatures. But rather than letting humans off the hook, a new study in the leading journal Science adds support to the idea that the oceans are taking up some of the excess heat, at least for the moment.

In a reconstruction of Pacific Ocean temperatures in the last 10,000 years, researchers have found that its middle depths have warmed 15 times faster in the last 60 years than they did during apparent natural warming cycles in the previous 10,000.

"We're experimenting by putting all this heat in the ocean without quite knowing how it's going to come back out and affect climate," said study coauthor Braddock Linsley, a climate scientist at Columbia University's Lamont-Doherty Earth Observatory. "It's not so much the magnitude of the change, but the rate of change."

In its latest report, released in September, the UN's Intergovernmental Panel on Climate Change (IPCC) noted the recent slowdown in the rate of global warming. While global temperatures rose by about one-fifth of a degree Fahrenheit per decade from the 1950s through 1990s, warming slowed to just half that rate after the record hot year of 1998.

The IPCC has attributed the pause to natural climate fluctuations caused by volcanic eruptions, changes in solar intensity, and the movement of heat through the ocean. Many scientists note that 1998 was an exceptionally hot year even by modern standards, and so any average rise using it as a starting point would downplay the longer-term warming trend.

The IPCC scientists agree that much of the heat that humans have put into the atmosphere since the 1970s through greenhouse gas emissions probably has been absorbed by the ocean. However, the findings in Science put this idea into a long-term context, and suggest that the oceans may be storing even more of the effects of human emissions than scientists have so far realized.

"We may have underestimated the efficiency of the oceans as a storehouse for heat and energy," said study lead author, Yair Rosenthal, a climate scientist at Rutgers University. "It may buy us some time - how much time, I don't really know. But it's not going to stop climate change."

Ocean heat is typically measured from buoys dispersed throughout the ocean, and with instruments lowered from ships, with reliable records at least in some places going back to the 1960s. To look back farther in time, scientists have developed ways to analyze the chemistry of ancient marine life to reconstruct the climates in which they lived.

In a 2003 expedition to Indonesia, the researchers collected cores of sediment from the seas where water from the Pacific flows into the Indian Ocean.

By measuring the levels of magnesium to calcium in the shells of Hyalinea balthica, a one-celled organism buried in those sediments, the researchers estimated the temperature of the middle-depth waters where H. Balthica lived, from about 1,500 to 3,000 feet down.

The temperature record there reflects middle-depth temperatures throughout the western Pacific, the researchers say, since the waters around Indonesia originate from the mid-depths of the North and South Pacific.

Though the climate of the last 10,000 years has been thought to be relatively stable, the researchers found that the Pacific intermediate depths have generally been cooling during that time, though with various ups and downs.

From about 7,000 years ago until the start of the Medieval Warm Period in northern Europe, at about 1100, the water cooled gradually, by almost 1 degree C, or almost 2 degrees F.

The rate of cooling then picked up during the so-called Little Ice Age that followed, dropping another 1 degree C, or 2 degrees F, until about 1600. The authors attribute the cooling from 7,000 years ago until the Medieval Warm Period to changes in Earth's orientation toward the sun, which affected how much sunlight fell on both poles.

In 1600 or so, temperatures started gradually going back up. Then, over the last 60 years, water column temperatures, averaged from the surface to 2,200 feet, increased 0.18 degrees C, or .32 degrees F. That might seem small in the scheme of things, but it's a rate of warming 15 times faster than at any period in the last 10,000 years, said Linsley.

One explanation for the recent slowdown in global warming is that a prolonged La Nina-like cooling of eastern Pacific surface waters has helped to offset the global rise in temperatures from greenhouse gases.

In a study in the journal Nature in August, climate modelers at the Scripps Institution of Oceanography showed that La Nina cooling in the Pacific seemed to suppress global average temperatures during northern hemisphere winters but allowed temperatures to rise during northern hemisphere summers, explaining last year's record U.S. heat wave and the ongoing loss of Arctic sea ice.

When the La Nina cycle switches, and the Pacific reverts to a warmer than usual El Nino phase, global temperatures may likely shoot up again, along with the rate of warming.

"With global warming you don't see a gradual warming from one year to the next," said Kevin Trenberth, a climate scientist at the National Center for Atmospheric Research in Boulder, Colo., who was not involved in the research.

"It's more like a staircase. You trot along with nothing much happening for 10 years and then suddenly you have a jump and things never go back to the previous level again."

The study's long-term perspective suggests that the recent pause in global warming may just reflect random variations in heat going between atmosphere and ocean, with little long-term importance, says Drew Shindell, a climate scientist with joint appointments at Columbia's Earth Institute and the NASA Goddard Institute for Space Studies, and a lead author on the latest IPCC report.

"Surface temperature is only one indicator of climate change," he said. "Looking at the total energy stored by the climate system or multiple indicators--glacier melting, water vapor in the atmosphere, snow cover, and so on-may be more useful than looking at surface temperature alone."

The study's third author, Delia Oppo, is a climate scientist at Woods Hole Oceanographic Institution. Watch the video here

.


Related Links
The Earth Institute at Columbia University
Climate Science News - Modeling, Mitigation Adaptation






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





CLIMATE SCIENCE
Geoengineering the climate would reduce vital rains
Boulder, CO (SPX) Nov 05, 2013
Although a significant build-up in greenhouse gases in the atmosphere would alter worldwide precipitation patterns, a widely discussed technological approach to reducing future global warming would also interfere with rainfall and snowfall, new research shows. The international study finds that a massive increase in greenhouse gases and warming of the planet would spur a nearly 7 percent g ... read more


CLIMATE SCIENCE
Crowdfunded Lunar Spacecraft Reaches Funding Milestone

LADEE Continues To Settle Into Operational Lunar Orbit

NASA's moon landing remembered as a promise of a 'future which never happened'

Russia could build manned lunar base

CLIMATE SCIENCE
India reaches for Mars on prestige space mission

India mission to Mars blasts off successfully

Mars Mission: India's Tryst with the Red Planet

Martian box of delights

CLIMATE SCIENCE
A look at recent tech sector IPOs

NASA's Orion Spacecraft Comes to Life

Flights of Fancy

NewSpace Business Plan Competition 2013 Winners Announced

CLIMATE SCIENCE
China shows off moon rover model before space launch

China providing space training

China launches experimental satellite Shijian-16

China Moon Rover A New Opportunity To Explore Our Nearest Neighbor

CLIMATE SCIENCE
Spaceflight Joins with NanoRacks to Deploy Satellites from the ISS

Crew Completes Preparations for Soyuz Move

Mission accomplished for Europe's cargo freighter

Soyuz changes parking spots at space station, making way for new crew

CLIMATE SCIENCE
Kazakhstan say Baikonur launch site may be open to Western countries

ESA Swarm launch postponed

Europe's fifth ATV for launch by Arianespace begins its pre-flight checkout at the Spaceport

ILS Proton Launches Sirius FM-6 Satellite

CLIMATE SCIENCE
One in five Sun-like stars may have Earth-like planets

Mystery World Baffles Astronomers

Researchers discover that an exoplanet is Earth-like in mass and size

'Hellish' exoplanet has Earth-like mass: research

CLIMATE SCIENCE
Plasmonic crystal alters to match light-frequency source

Virtually numbed: Immersive video gaming alters real-life experience

New material for quantum computing discovered out of the blue

Google boss says US data spying is "outrageous"




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement