CO2

>CO2
>Greenhouse gas
>Causes global warming

>Water vapor
>Greenhouse gas
>Doesn't cause global warming

What CO2 has that water vapor doesn't?

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ipcc-nggip.iges.or.jp/faq/faq.html
en.wikipedia.org/wiki/Global_warming_potential
hitran.org/
nature.com/nature/journal/v349/n6309/abs/349500a0.html
ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
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Entirely different physical properties
Lrn2 UV spectrums

Entirely different physical properties
Lrn2 UV spectrum

Why just UV? IR doesn't count?

long-ass residence time in the atmosphere
not in equilibrium with a huge ocean of the stuff in liquid phase

basically, CO2 hangs out in the atmosphere for a while, while water vapor precipitates out relatively quickly.

Water vapor also causes clouds to form, raising albedo.

global warming is not real
the earths surface or atmosphere doesn't cool itself via infrared radiation

>the earths surface or atmosphere doesn't cool itself via infrared radiation

Every macroscopic, physical body with a finite temperature does.

I believe he's attempting a "troll" by saying something obviously untrue in order to receive attention and replies correcting him. This is considered "humorous" by some.

That doesn't mean the water vapor disappears.

Also that doesn't mean that the CO2 does not end up being absorbed by the oceans and the plants.
Actually the amount of water vapor is about 30000 ppm, meanwhile CO2 in the atmosphere is about 400 ppm. Why isn't water vapor counted when calculating the greenhouse effect?

Hm, yes. Quite.

>That doesn't mean the water vapor disappears.
There's this thing called condensation. Ever seen it rain?

>Also that doesn't mean that the CO2 does not end up being absorbed by the oceans and the plants.
More is absorbed than emitted thanks to man.

>Actually the amount of water vapor is about 30000 ppm, meanwhile CO2 in the atmosphere is about 400 ppm. Why isn't water vapor counted when calculating the greenhouse effect?
It is. But because it is quickly reabsorbed and fluctuates quite wildly from day to day, while CO2 is controllable, CO2 is the far more important factor from an environmental perspective.

>Why isn't water vapor counted when calculating the greenhouse effect?
Where did you get the idea that it's not? Water vapor forms a positive feedback loop with CO2:

Warming -> more water vapor and CO2 evaporating out of the oceans -> more warming from greenhouse effect -> ...

In the past, the orbital eccentricity of the earth would lead to warming from more solar radiance, which would lead to this cycle starting. This is why historically you see increases in CO2 following increases in temperature. Today, the greenhouse effect from CO2 emitted by man started the warming cycle. Water vapor is a very important part of this, but it's not directly effected by man.

>There's this thing called condensation. Ever seen it rain?
That means all water vapor on earth condenses and the atmosphere becomes 100% dry? No.

>More is absorbed than emitted thanks to man.
You meant More is emitted than absorbed, I think.

>CO2 is the far more important factor from an environmental perspective.
Why? If the amount of water vapor is about 75 times the amount of CO2?

>Where did you get the idea that it's not?
ipcc-nggip.iges.or.jp/faq/faq.html
>Why is water vapour not covered by the IPCC Guidelines?
>A: There is a natural greenhouse effect which is largely driven by water vapour (H2O) and other greenhouse gases which occur to a certain extent naturally in the atmosphere. However anthropogenic emissions of water vapour do not contribute significantly to the change of atmospheric water vapour concentration. Thus, the IPCC Guidelines do not deal with water vapour as an anthropogenic GHG.

I know we basically can't change the amount of water vapor.
But the IPCC just ignores the water vapor from its predictions.

>But the IPCC just ignores the water vapor from its predictions.
Bullcrap on at least two levels.

First, the IPCC doesn't run models or predictions.
Secondly, water vapour IR absorption is in fucking every radiative transfer model via standard absorption coefficient tables such as HITRAN.

The effect of CO2 is mostly imaginary. The dominant effect are the solar activity cycles and all that entails (cosmic rays, clouds). We will soon have to realize that and the CO2 hypnosis will collapse.

I'm an Earth Science student. I've taken classes explaining exactly this. Try and listen.

There are positive feedback loops and negative feedback loops.

A positive feedback loop. The louder the children get the angrier the parents become. The angrier the parents become the louder the children get.

This goes to infinity. Got it?

Negative feedback loop. The less students there are the more students enter school. The more students in school the more they graduate. The more they graduate the less students there are in school.

Negative feedback loops lead to equilibrium.

Water vapor is a POSITIVE FEEDBACK LOOP. The hotter it gets the more water evaporates. The more water evaporates the hotter it gets.

Likewise. The colder it gets the more water freezes. The more water freezes the less water vapor there is. The less water vapor there is the colder it gets.

We've known this for centuries. It's absolutely nothing new. We've known that there must be something that regulates temperature and it CANNOT be water vapor. Water vapor as a temperature regulator is impossible.

>comic sans

I tried to find the water vapour IR absortion without success. But the radiance seems a better property, right? Like in the pic of the first post. There's CO2, CO, etc... But not water vapor.
There's a measure called Global warming potential, and at least in Wikipedia it's said it's hard to calculate to calculate water vapor's GWP.

en.wikipedia.org/wiki/Global_warming_potential
>Water vapour has a profound infrared absorption spectrum with more and broader absorption bands than CO2, and also absorbs non-zero amounts of radiation in its low absorbing spectral regions,[16] (see greenhouse gas (GHG)), its GWP is therefore difficult to calculate. Further, its concentration in the atmosphere depends on air temperature and water availability; using a global average temperature of ~16 °C, for example, creates an average humidity of ~18,000ppm at sea level (CO2 is ~400ppm[17] and so concentrations of [H2O]/[CO2] ~ 45x). Another issue with calculating GWP is that, unlike other GHG, water vapor does not decay in the environment, so an average over some time period or some other measure consistent with "time dependent decay," q.v., above, must be used in lieu of the time dependent decay of artificial or excess CO2, molecules. Other factors complicating its calculation are the Earth's temperature distribution, and the differing land masses in the Northern and Southern hemispheres.

I understand positive and negative feeedback loops, but thanks for the explanation.
>Water vapor as a temperature regulator is impossible.
Why? Isn't water vapor a gas like many others? It does have a property called specific heat capacity, which means that it's able to store temperature, receive heat when it's colder than the surroundings and provide heat when it's warmer than the surroundings.
Also the specific heat capacity is nearly equal to that of the CO2.

>I tried to find the water vapour IR absortion without success.
Try here:
hitran.org/

>Like in the pic of the first post. There's CO2, CO, etc... But not water vapor.

It's because water vapor is fucking everywhere in this absorption spectrum, they probably didn't need to specifically label it.

heat is spread around the earth primarily via convection

>heat is spread around the earth primarily via convection

I would still argue that a body with finite temperature T > 0 will exhibit the features known from a Planck'ian black-body and thus emit a continuous spectrum of thermal radiation, thus losing energy that way.

>Water vapor is a POSITIVE FEEDBACK LOOP.

This is a pretty bold assumption based on what evidence exactly?
Are you unaware that clouds block a hell of a lot of sunlight?

Paper from 1991
nature.com/nature/journal/v349/n6309/abs/349500a0.html

The hypothesis is older than you are, and it's been taken as confirmed by a number of publications now. You're welcome to make a contribution, thought, and publish something that would prove them wrong or show an error in their works.

>That means all water vapor on earth condenses and the atmosphere becomes 100% dry? No.
Nice pedantry. What's the point?

>Why? If the amount of water vapor is about 75 times the amount of CO2?
I just explained why. Then you cut off the explanation in your quote and asked why. Let's try again:

1. Water vapor is reabsorbed very quickly. It fluctuates wildly from day to day.

2. Man has no significant direct effect or control on water vapor

3. Water vapor increases albedo of the earth, which counteracts its greenhouse effect.


>I know we basically can't change the amount of water vapor.
>But the IPCC just ignores the water vapor from its predictions.
That's not what the website says though. It says that the IPCC does not treat it as an anthropogenic GHG, not that it doesn't treat it as a GHG or doesn't use it in models and predictions. Are you being deliberately dense?

Water Vapor was not considered.
Figure 1: Spectrum of the greenhouse radiation measured at the surface. Greenhouse effect from water vapour is filtered out, showing the contributions of other greenhouse gases (Evans 2006).
ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm

>heat is spread around the earth primarily via convection
That's a non-sequitur since the question is how does heat *escape* the earth? Hint: not by convection.

Pick this then.
I usually work with very narrow bands, so forgive me for not being able to point out H2O contributions in an ultra-wide band plot.

ok but assuming the earth dissapates heat like a black body, and the atmosphere is a single layer it must pass through is a completely wrong way to view the atmosphere.

If it was not considered how was it filtered out? You are just interpreting things obtusely without any concern to relevant meaning. In order to measure the IR spectrum of any gas you need to filter out the IR spectrum of water since it covers the entire spectrum. This does NOT mean the effect of water vapor is ignored in climatology, you ignoramus.

My point is that water vapor do absorb temperature and that the water vapor is always present in the atmosphere.

3. Water vapor increases albedo of the earth, which counteracts its greenhouse effect.
That's true. The clouds reflect most of the solar radiation before it reaches the surface. But of what is absorbed by the surface has it's temperature increased, therefore increasing the amount of water vapour and the temperature of the atmosphere.

>It says that the IPCC does not treat it as an anthropogenic GHG
You're right. I didn't read it well.

One truly magical difference - they still haven't found a way to TAX water vapor.

Water vapor could easily be taxed as essentially the only mass producer of water vapor is heavy industry.

>blames an increasing trend with no sign of 11-year periodicity on solar activity
o I am laffin

this

there's a good reason to do that.
water in the lower atmosphere varies a lot (higher humidity near bodies of water, lower humidity in the horse latitudes) and so for a general look at atmospheric absorption, it's best to look only at the effects of dry air.

Just because water vapor in the lower atmosphere varies a lot, it's greenhouse radiation shouldn't be considered independently?

The point is that due to it's high variability, water vapour is relevant on timescales of days. If your interest is in long-term trends, h2o becomes a bystander - while having large effects on climate and weather, water vapour never is and never was a primary driver.

>being this wilfully retarded

Water vapor existed even before the oceans were formed on Earth.
>water vapour is relevant on timescales of days.
Get a load of this guy.

I think you have some horrible confusion about what weather is and how it works.