Our Terms of Service and Privacy Policy have changed.

By continuing to use this site, you are agreeing to the new Privacy Policy and Terms of Service.

3 of 8
A permanent haze
A permanent haze
You can go a step further than just whitening clouds by actually putting more clouds in the atmosphere.

How it works: Volcanic eruptions have shown that putting sulfur in the atmosphere cools the planet. Rain drops react with the sulfur particles high in the stratosphere, forming clouds that keep out sunlight.

The clouds are thin, so the sky would be less like London and more like a hazy day at the beach.

The sulfur is cheap, and comes from an activity we're well versed in: burning oil and coal. It could be delivered into the stratosphere by high flying jets, artillery, or hot air balloons, pictured here.

Another idea is to deliver the sulfur to the stratosphere via an extremely long hose kept aloft by a series of balloons. This method is said to be cheaper than others.

Why it might not work: A major downside is what effect this could have on rain patterns, said Alan Robock, an environmental sciences professor at Rutgers University. It may disrupt the monsoons in Asia, rains that sustain food crops for billions of people.

And like most geoengineerng schemes, it would need to be done continuously, for as long as carbon levels stayed high, or else the earth would rapidly warm up again.

NEXT: Carbon-sucking machines

Last updated December 02 2009: 10:52 AM ET
Email | Print | Share  |  RSS
google my aol my msn my yahoo! netvibes
Paste this link into your favorite RSS desktop reader
See all CNNMoney.com RSS FEEDS (close)
More Galleries
Black Friday 2015 in pictures Shoppers around the country braved the crowds to get their hands on the best Black Friday deals. More
Driving the ultimate in '50s Mercedes-Benz style The SC was the car that re-introduced Mercedes-Benz as a global luxury car icon. More
Driving the world's first car Driving a replica of the 1886 Benz Patent Motorwagen, the first internal combustion automobile. More

Special Offer