Featured Research

from universities, journals, and other organizations

Geoengineering for global warming: Increasing aerosols in atmosphere would make sky whiter

Date:
May 31, 2012
Source:
Carnegie Institution
Summary:
One idea for fighting global warming is to increase the amount of aerosols in the atmosphere, scattering incoming solar energy away from Earth's surface. But scientists theorize that this solar geoengineering could have a side effect of whitening the sky during the day. New research indicates that blocking 2 percent of the sun's light would make the sky three-to-five times brighter, as well as whiter.

One idea for fighting global warming is to increase the amount of aerosols in the atmosphere, scattering incoming solar energy away from Earth's surface. But scientists theorize that this solar geoengineering could have a side effect of whitening the sky during the day.
Credit: xuxw / Fotolia

One idea for fighting global warming is to increase the amount of aerosols in the atmosphere, scattering incoming solar energy away from Earth's surface. But scientists theorize that this solar geoengineering could have a side effect of whitening the sky during the day. New research from Carnegie's Ben Kravitz and Ken Caldeira indicates that blocking 2% of the sun's light would make the sky three-to-five times brighter, as well as whiter.

Their work is published June 1st in Geophysical Research Letters, a journal of the American Geophysical Union.

Carbon dioxide emissions from the burning of coal, oil, and gas have been increasing over the past decades, causing Earth to get hotter and hotter. Large volcanic eruptions cool the planet by creating lots of small particles in the stratosphere, but the particles fall out within a couple of years, and the planet heats back up. The idea behind solar geoengineering is to constantly replenish a layer of small particles in the stratosphere, mimicking this volcanic aftermath and scattering sunlight back to space.

Using advanced models, Kravitz and Caldeira -- along with Douglas MacMartin from the California Institute of Technology -- examined changes to sky color and brightness from using sulfate-based aerosols in this way. They found that, depending on the size of the particles, the sky would whiten during the day and sunsets would have afterglows.

Their models predict that the sky would still be blue, but it would be a lighter shade than what most people are used to looking at now. The research team's work shows that skies everywhere could look like those over urban areas in a world with this type of geoengineering taking place. In urban areas, the sky often looks hazy and white.

"These results give people one more thing to consider before deciding whether we really want to go down this road," Kravitz said. "Although our study did not address the potential psychological impact of these changes to the sky, they are important to consider as well."

There are several larger environmental implications to the group's findings, too. Because plants grow more efficiently under diffuse light conditions such as this, global photosynthetic activity could increase, pulling more of the greenhouse gas carbon dioxide out of the atmosphere. On the other hand, the effectiveness of solar power could be diminished, as less sunlight would reach solar-power generators. "I hope that we never get to the point where people feel the need to spray aerosols in the sky to offset rampant global warming," Caldeira said. "This is one study where I am not eager to have our predictions proven right by a global stratospheric aerosol layer in the real world."


Story Source:

The above story is based on materials provided by Carnegie Institution. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ben Kravitz, Douglas G MacMartin, Ken Caldeira. Geoengineering: Whiter Skies? Geophysical Research Letters, 2012; DOI: 10.1029/2012GL051652

Cite This Page:

Carnegie Institution. "Geoengineering for global warming: Increasing aerosols in atmosphere would make sky whiter." ScienceDaily. ScienceDaily, 31 May 2012. <www.sciencedaily.com/releases/2012/05/120531112614.htm>.
Carnegie Institution. (2012, May 31). Geoengineering for global warming: Increasing aerosols in atmosphere would make sky whiter. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2012/05/120531112614.htm
Carnegie Institution. "Geoengineering for global warming: Increasing aerosols in atmosphere would make sky whiter." ScienceDaily. www.sciencedaily.com/releases/2012/05/120531112614.htm (accessed July 24, 2014).

Share This




More Earth & Climate News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Higgins Breaks Record at Mt. Washington

Higgins Breaks Record at Mt. Washington

Driving Sports (July 24, 2014) Subaru Rally Team USA drivers David Higgins and Travis Pastrana face off against a global contingent of racers at the annual Mt. Washington Hillclimb in New Hampshire. Includes exclusive in-car footage from Higgins' record attempt. Video provided by Driving Sports
Powered by NewsLook.com
Storm Kills Three, Injures 20 at Virginia Campground

Storm Kills Three, Injures 20 at Virginia Campground

Reuters - US Online Video (July 24, 2014) A likely tornado tears through an eastern Virginia campground, killing three and injuring at least 20. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins