(Anna Lubovedskaya/iStockphoto)

Quick, what’s the biggest problem facing Earth’s atmosphere today? Too late. The correct answer is increasing carbon dioxide levels. CO2 isn’t the harshest greenhouse gas, but it’s the one that is emitted the most and it’s capable of causing quite a bit of damage. There’s a finite amount of carbon dioxide in Earth’s biogeochemical carbon cycle; the problem is we humans are releasing CO2 in droves, artificially accelerating the carbon cycle through means like removing fossil fuels and burning them.

The best solution to this problem would be to simply stop releasing CO2, but see, we have this thing called the global economy and it runs on coal and oil. Instead, research has yielded a potentially equally acceptable solution: simply capturing the carbon dioxide before it makes its way into the air. This is called carbon capture.

There are a couple of ways to capture CO2, and most are centered around coal, which — even in clean form — is exceptionally dirty. (There’s a single coal-fire power plant run by Southern Company here in Georgia that emits more CO2 than the entire electricity infrastructure of Brazil.) One method is to remove carbon dioxide from coal before it’s burned. Another is to catch it in the flues before it makes its way out in a puff of smoke. Researchers at Georgia Tech (boo!) have come up with a synthetic, sand-like material that can catch CO2 and trap it. The stuff is called hyperbranched aminosilica, which is Latin for really, really branched aminosilica, I believe.

Now that you’ve got it captured, what to do with the CO2? Here’s where the storage part comes in. Most CO2 storage going on today has to do with trapping the stuff below ground; another proposal is to keep it in liquid form in bags along the continental shelf. Either way, it’s possible we will find a way to regenerate captured carbon into a synthetic fossil fuel, forming a closed loop where fuel is burned, CO2 is captured and reused once more. Pretty sweet, huh?

Boo-ya! That’s one down; four to go.

The rest of the list:

No. 4: Green Brownfield Remediation
No. 3: Biohydrocarbons
No. 2: Any Kind of Turbine
No. 1: Water Desalination

More on HowStuffWorks.com:
How Carbon Capture Works
Can we bury our CO2 problem in the ocean?
Can we make tailpipes that capture CO2?
What is clean coal technology?