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17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
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ScienceShot: Climate Combat Could Turn Sky White
1 June 2012 1:30 pm
Talk about a vanilla sky. A scheme that would add light-colored, highly reflective particles to the atmosphere to reflect sunlight and cool the planet would significantly whiten the heavens, a new study suggests. Researchers analyzed the effect of adding enough aerosols to block 2% of the sun's light from reaching the ground, the amount needed to offset a carbon dioxide concentration twice that found in the air before the Industrial Revolution. (The approach is one of a series of so-called geoengineering efforts to tinker with the planet to mitigate the effects of climate change.) Depending on the size of the particles injected into the atmosphere, which would likely range between 0.7 and 0.9 micrometers in diameter, the aerosols' light-scattering effect would render the sky between three and five times brighter than it is now, the researchers report online today in Geophysical Research Letters. Most infrared wavelengths outbound from Earth wouldn't be strongly scattered by aerosols this size, so the particles wouldn't effectively trap heat in the atmosphere. But in visible wavelengths, the particles would tend to scatter more red light than blue, rendering the heavens whiter—in essence, giving the deep-blue sky now seen in remote areas such as Utah's Arches National Park (shown) the same hazy appearance often found in urban areas. Other side effects would include redder sunsets and brighter glows in the sky just after sunset—the same sort of phenomena seen after large volcanic eruptions, which spew large amounts of geological aerosols high into the atmosphere until natural processes clear the air.
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