Comments on: What’s in the air?

By: greg laden

greg laden — Sun, 14 Sep 2008 09:18:25 +0000

I would assume the Hawaiian research station famous for its CO2 data has that as well. There are national archives of atmospheric data. Poke around in NOAH, you’ll find it.Report back.

By: james smith

james smith — Sun, 14 Sep 2008 06:50:14 +0000

Hi Greg, do you know of any links to data regarding present day oxygen levels around the world and any previous data recorded, the only dates I have found information on is 1950 at 21% and 1997 at 19%, with the increase of fresh water into the artic regions along with pollution and forest devastation I would say that humanity is in big trouble

By: ecoli

ecoli — Sat, 31 May 2008 15:29:34 +0000

@yogi-one, above me.The form of nitrogen you’re thinking of is ammonia (NH3), which results from the decomposition of animal wastes. However, this is not a gas, and doesn’t enter the atmosphere.However, another product of animal digestion is methane (CH3) which is, in fact, a greenhouse gas. In terms of a scale, methane is a stronger greehouse gas than carbon dioxide, but it exists in much smaller amounts, so isn’t as big a player. You are right in saying that the amount of livestock we keep can and does contribute to global warming through methane levels. I don’t believe we can accurately predict what that affect is, yet, unfortunately.

By: yogi-one

yogi-one — Sat, 19 Apr 2008 19:01:03 +0000

Thanks, Greg – my roommate’s 9-year-old son asked me that last week and I found myself stumbling for an answer. All us common folk know oxygen is a major component, but, seeing as how pure oxygen is rocket fuel, and obviously we don’t go around sucking in pure rocket fuel 24/7, I could not remember the other primary components.I was forgetting about the nitrogen. Also what you have written on the “dirt” is very interesting.Could someone say something more about nitrogen – that is appearing more and more in debates about climate change. Apparently nitrogen is a major component of many animals’- especially cattle – waste products.

By: Dizzlski

Dizzlski — Sat, 19 Apr 2008 10:45:44 +0000

And don’t forget, in the nuclear navy (US) air is: 80% oxygen, 20% nitrogen, and 1% other.

By: The Science Pundit

The Science Pundit — Sat, 19 Apr 2008 08:21:21 +0000

Water vapor is less dense that air in general and high humidity decreases air density and also decreases percentage of oxygen in the air.

Yes, I remember this from The Physics of Baseball as the reason that you're likely to see more home runs on humid days.It's a testimony to the power of the hydrogen bond that water has the smallest MW of all the major components of air (and I'm even throwing Argon in for good measure), and yet is the only component that is a stable liquid at ambient temperature and pressure.

By: BlindSquirrel

BlindSquirrel — Fri, 18 Apr 2008 19:22:42 +0000

Please ignore above post I misread the comment. Time for my nap.

By: BlindSquirrel

BlindSquirrel — Fri, 18 Apr 2008 19:19:52 +0000

My information has water vapor as less dense than air. Also, bear in mind that water vapor is “invisible”, ie clear and colorless.

By: Jim Thomerson

Jim Thomerson — Fri, 18 Apr 2008 18:27:14 +0000

As you know, oxygen is a deadly poison. We will all die of oxygen poisioning unless something else gets us first. I read someplace, many years ago, that the threshold value of enough oxygen in the atmosphere to make it worthwhile to go to oxidative metabolism was 4%. Water vapor is less dense that air in general and high humidity decreases air density and also decreases percentage of oxygen in the air. Pilots are well aware of what is called “density altitude”, a mix of real altitude, humidity and temperature. On a hot wet day, up in the mountains, you don’t want to load your airplane too heavy.