Changing Air
It's just air, isn't it?
What is AIR?
- Air is mostly nitrogen
- 1/5 of it is the oxygen we need to breathe
- Also a bit of other gases
- Can this little bit make a difference - YES!
The Ozone Hole
The air around our earth protects us from damaging UV light - what sunburns you. Without the air the UV light would do a lot worse than sunburn you.
The ozone "hole" is a a region in the upper atmosphere of exceptionally depleted ozone. Ozone (O3) is transformed oxygen (O2) that efficiently absorbs UV light.
How do we know there is an ozone hole? We can measure the UV light getting to the surface under the hole or we can stand there in the sunlight and get fried.
What caused the ozone hole? CFC's - a very specific chemical used mostly in air conditioning.
How did we figure out that CFC's were the problem?
We could measure them in the ozone hole and measure in a lab how good they were at destroying ozone.
How were we finally certain that CFC's were the problem? They were banned, how much there was in the air decreased, and the ozone hole healed.
Why does this matter for investigating climate change? Now we know for certain that a little bit of gas can make a big difference in the air around the earth and how it affects us.
How much CFC's are we talking about? 1 CFC in 1 billion air molecules. Not much.
Did the air conditioner industry claim this research was wrong? You bet!
Heat Absorbing Gases
Does air absorb sunlight?
- Yes, but not nitrogen or oxygen
What part of air does air absorb sunlight?
- Water (vapor) - chemical formula H2O
- CO2 - Carbon Dioxide
- Methane - chemical formula CH4
- Nitrous Oxide - chemical formula NO
- Ozone - chemical formula O3
How do we know these gases absorb light (which is heat)?
- Absorption of specific gases easily and accurately measured by lasers.
- We know the amount of light reaching the earth - satellite measurements
- We know how much light reaches the ground (on a clear day)
- The difference is absorbed in the atmosphere
- The atmosphere measurements of gas concentration agrees with lab gas measurements.
Doesn't this light/heat get absorbed by the ground anyhow?
- Bright surfaces like snow, ice, and clouds reflect the most, oceans reflect the least.
- At night the entire earth radiates heat
- The absorbing gases trap this heat that would otherwise go into space and cool the earth.
How much light/heat do the various gases absorb?
Where do these gases come from?
How much do people put out?
How much is that?
- The numbers are huge.
- The amount of CO2 in the atmosphere is far higher than it has been for a long, long time.
Email: thought@thoughtventions.com
Email: thought@thoughtventions.com
Last updated: September 2020