This is Scientific American 60-Second Earth. I'm David Biello. Your minute begins now.
Look up in the sky! It's a bird! It's a plane!
Yes, it's a plane.
On any given day odds are you'll see several contrails, some slowly spreading out to form high, cirrus clouds.
Air travel just keeps growing and the atmosphere is starting to notice.
The act of burning kerosene and other aviation fuels to power jet engines and propellers means carbon dioxide emissions, among other types of pollution.
And that CO2, plus water vapor and the like is deposited high in the atmosphere, where it contributes most effectively to global warming.
The world's nations have spent years trying to come up with a way to restrain air travel emissions.
And this week the International Civil Aviation Organization, the ICAO, a UN body, agreed on a plan to do just that—that won't take effect until 2020.
Hence the flyby in Montreal of a chartered plane trailing the banner: "Can't Spell Procrastination without ICAO."
Solutions exist for airplane emissions, ranging from low-carbon biofuels to more efficient engines and lighter plane bodies.
If an airplane powered only by sunshine can fly across the U.S., there's reason to believe air traffic can be cleaned up, and soon.
Your minute is up, for Scientific American 60-Second Earth. I'm David Biello.