Subscribe free to our newsletters via your
. 24/7 Space News .




CLIMATE SCIENCE
Experiment would test cloud geoengineering as way to slow warming
by Staff Writers
Seattle WA (SPX) Aug 21, 2012


File image.

Even though it sounds like science fiction, researchers are taking a second look at a controversial idea that uses futuristic ships to shoot salt water high into the sky over the oceans, creating clouds that reflect sunlight and thus counter global warming.

University of Washington atmospheric physicist Rob Wood describes a possible way to run an experiment to test the concept on a small scale in a comprehensive paper published this month in the journal Philosophical Transactions of the Royal Society.

The point of the paper - which includes updates on the latest study into what kind of ship would be best to spray the salt water into the sky, how large the water droplets should be and the potential climatological impacts - is to encourage more scientists to consider the idea of marine cloud brightening and even poke holes in it. He and a colleague detail an experiment to test the concept.

"What we're trying to do is make the case that this is a beneficial experiment to do," Wood said. With enough interest in cloud brightening from the scientific community, funding for an experiment may become possible, he said.

The theory behind so-called marine cloud brightening is that adding particles, in this case sea salt, to the sky over the ocean would form large, long-lived clouds. Clouds appear when water forms around particles. Since there is a limited amount of water in the air, adding more particles creates more, but smaller, droplets.

"It turns out that a greater number of smaller drops has a greater surface area, so it means the clouds reflect a greater amount of light back into space," Wood said. That creates a cooling effect on Earth.

Marine cloud brightening is part of a broader concept known as geoengineering which encompasses efforts to use technology to manipulate the environment. Brightening, like other geoengineering proposals, is controversial for its ethical and political ramifications and the uncertainty around its impact. But those aren't reasons not to study it, Wood said.

"I would rather that responsible scientists test the idea than groups that might have a vested interest in proving its success," he said. The danger with private organizations experimenting with geoengineering is that "there is an assumption that it's got to work," he said.

Wood and his colleagues propose trying a small-scale experiment to test feasibility and begin to study effects. The test should start by deploying sprayers on a ship or barge to ensure that they can inject enough particles of the targeted size to the appropriate elevation, Wood and a colleague wrote in the report. An airplane equipped with sensors would study the physical and chemical characteristics of the particles and how they disperse.

The next step would be to use additional airplanes to study how the cloud develops and how long it remains. The final phase of the experiment would send out five to 10 ships spread out across a 100 kilometer, or 62 mile, stretch. The resulting clouds would be large enough so that scientists could use satellites to examine them and their ability to reflect light.

Wood said there is very little chance of long-term effects from such an experiment. Based on studies of pollutants, which emit particles that cause a similar reaction in clouds, scientists know that the impact of adding particles to clouds lasts only a few days.

Still, such an experiment would be unusual in the world of climate science, where scientists observe rather than actually try to change the atmosphere.

Wood notes that running the experiment would advance knowledge around how particles like pollutants impact the climate, although the main reason to do it would be to test the geoengineering idea.

A phenomenon that inspired marine cloud brightening is ship trails: clouds that form behind the paths of ships crossing the ocean, similar to the trails that airplanes leave across the sky. Ship trails form around particles released from burning fuel.

But in some cases ship trails make clouds darker. "We don't really know why that is," Wood said.

Despite increasing interest from scientists like Wood, there is still strong resistance to cloud brightening.

"It's a quick-fix idea when really what we need to do is move toward a low-carbon emission economy, which is turning out to be a long process," Wood said. "I think we ought to know about the possibilities, just in case."

The authors of the paper are treading cautiously.

"We stress that there would be no justification for deployment of [marine cloud brightening] unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favor of such action," they wrote in the paper's summary.

There are 25 authors on the paper, including scientists from University of Leeds, University of Edinburgh and the Pacific Northwest National Laboratory. The lead author is John Latham of the National Center for Atmospheric Research and the University of Manchester, who pioneered the idea of marine cloud brightening.

.


Related Links
University of Washington
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








CLIMATE SCIENCE
Studies shed light on why species stay or go in response to climate change
Berkeley CA (SPX) Aug 21, 2012
Two new studies by scientists at UC Berkeley provide a clearer picture of why some species move in response to climate change, and where they go. One study, published online in the journal Global Change Biology, finds that changes in precipitation have been underappreciated as a factor in driving bird species out of their normal range. In the other study, published the journal Proceedings ... read more


CLIMATE SCIENCE
LRO Spectrometer Detects Helium in Moon's Atmosphere

NASA's 'Mighty Eagle' Robotic Prototype Lander Flies Again at Marshall

Roscosmos Announces Tender for Moon Rocket Design

US flags still on the moon, except one: NASA

CLIMATE SCIENCE
Curiosity rover set for first test drive

Rover's Laser Instrument Zaps First Martian Rock

Fantastic Phobos

New NASA Mission to Take First Look Deep Inside Mars

CLIMATE SCIENCE
For US students, plane tickets, TVs are relics

Voyager at 35: Break on Through to the Other Side

XCOR Becomes Corporate Sponsor of Uwingu, a Space Apps Company

Florida Spaceport Stakes Claim to Commercial Missions

CLIMATE SCIENCE
Is China Going to Blast Past America in Space?

Hong Kong people share joy of China's manned space program

China's Long March-5 carrier rocket engine undergoes testing

China to land first moon probe next year

CLIMATE SCIENCE
ISS Orbit Adjustment to Continue on August 22

Cosmonauts Begin First Expedition 32 Spacewalk

ATV-3 Vehicle Fails to Adjust Space Station Orbit

ISS crew to embark on two spacewalks in August

CLIMATE SCIENCE
Russian Booster Rocket Lifts US Satellite in Seaborne Launch

India's GSAT-10 satellite continues its checkout for the upcoming Arianespace Ariane 5 mission

Flight Readiness Review Complete; No Constraints to Aug. 23 Launch

Pre launch verifications are underway for next Soyuz mission

CLIMATE SCIENCE
First Evidence Discovered of Planet's Destruction by Its Star

Exoplanet hosting stars give further insights on planet formation

Five Potential Habitable Exoplanets Now

RIT Leads Development of Next-generation Infrared Detectors

CLIMATE SCIENCE
Yap.TV tunes Internet Age viewing for the world

Good vibrations

Britain and Ireland tuning into Netflix

Apple is most valuable company ever at $623 bn




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