Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Geoengineering could lead to a whiter sky

01.06.2012
One idea for fighting global warming is to increase the amount of aerosols in the atmosphere, scattering incoming solar energy away from the 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.

Carbon dioxide emissions from the burning of coal, oil, and gas have been increasing over the past decades, causing the Earth to get warmer. 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, Carnegie's Ben Kravitz and Ken 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 work will be published 1 June in Geophysical Research Letters, a journal of the American Geophysical Union.

The scientists' 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."

Title: "Geoengineering: Whiter Skies?"

Authors: Ben Kravitz: Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA; Douglas G MacMartin: Department of Control and Dynamical Systems, California Institute of Technology, Pasadena, California, USA; Ken Caldeira: Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA.

Contact Information for the Authors: Ben Kravitz, Email: bkravitz@stanford.edu

Kate Ramsayer | American Geophysical Union
Further information:
http://www.agu.org

More articles from Earth Sciences:

nachricht Modeling magma to find copper
13.01.2017 | Université de Genève

nachricht What makes erionite carcinogenic?
13.01.2017 | Friedrich-Schiller-Universität Jena

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Energy-Efficient Building Operation: Monitoring Platform MONDAS Identifies Energy-Saving Potential

16.01.2017 | Trade Fair News

Designing Architecture with Solar Building Envelopes

16.01.2017 | Architecture and Construction

Sensory Stimuli Control Dopamine in the Brain

13.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>