EXXON Contradicts its Own Scientists

[_Tobin]

Here is a chart using relative humidity and dew point:



Want me to do the math for you Brad?

[_Res Ipsa]

Here is a chart using relative humidity and dew point:



Want me to do the math for you Brad?

Please proceed, Tobinor.

[_Res Ipsa]

***Taps foot. Looks at watch.***

Must be some purty fancy math...

[_Tobin]

See the far end of the graph Brad? What percentage is 100 grams of 1kg? 10% Ohhh, such hard math.

[_Res Ipsa]

See the far end of the graph Brad? What percentage is 100 grams of 1kg? 10% Ohhh, such hard math.

At what temperature, Tobin?

Never mind. I'll save you the trouble. 122F and 100% humidity. And what does that have to do with earth's atmosphere?

I'll save you the trouble. Nothing!

You've made the ridiculous claim that 4% of the atmosphere is water vapor based on not a shred of evidence. Put up or shut up.

[Guest]

The role of water vapor in greenhouse effect:

It’s true that water vapor is the largest contributor to the Earth’s greenhouse effect. On average, it probably accounts for about 60% of the warming effect. However, water vapor does not control the Earth’s temperature, but is instead controlled by the temperature. This is because the temperature of the surrounding atmosphere limits the maximum amount of water vapor the atmosphere can contain. If a volume of air contains its maximum amount of water vapor and the temperature is decreased, some of the water vapor will condense to form liquid water. This is why clouds form as warm air containing water vapor rises and cools at higher altitudes where the water condenses to the tiny droplets that make up clouds.

The greenhouse effect that has maintained the Earth’s temperature at a level warm enough for human civilization to develop over the past several millennia is controlled by non-condensable gases, mainly carbon dioxide, CO2, with smaller contributions from methane, CH4, nitrous oxide, N2O, and ozone, O3. Since the middle of the 20th century, small amounts of man-made gases, mostly chlorine- and fluorine-containing solvents and refrigerants, have been added to the mix. Because these gases are not condensable at atmospheric temperatures and pressures, the atmosphere can pack in much more of these gases . Thus, CO2 (as well as CH4, N2O, and O3) has been building up in the atmosphere since the Industrial Revolution when we began burning large amounts of fossil fuel.

If there had been no increase in the amounts of non-condensable greenhouse gases, the amount of water vapor in the atmosphere would not have changed with all other variables remaining the same. The addition of the non-condensable gases causes the temperature to increase and this leads to an increase in water vapor that further increases the temperature. This is an example of a positive feedback effect. The warming due to increasing non-condensable gases causes more water vapor to enter the atmosphere, which adds to the effect of the non-condensables.

There is also a possibility that adding more water vapor to the atmosphere could produce a negative feedback effect. This could happen if more water vapor leads to more cloud formation. Clouds reflect sunlight and reduce the amount of energy that reaches the Earth’s surface to warm it. If the amount of solar warming decreases, then the temperature of the Earth would decrease. In that case, the effect of adding more water vapor would be cooling rather than warming. But cloud cover does mean more condensed water in the atmosphere, making for a stronger greenhouse effect than non-condensed water vapor alone – it is warmer on a cloudy winter day than on a clear one. Thus the possible positive and negative feedbacks associated with increased water vapor and cloud formation can cancel one another out and complicate matters. The actual balance between them is an active area of climate science research.


ACS CLIMATE SCIENCE TOOLKIT
About
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Energy Balance & Planetary Temperatures
Atmospheric Warming
Greenhouse Gases

This has been frequently pointed out, and is a matter of well established science about which there is no significant controversy among scientists.

Brad is certainly right that the claim that the water in the atmosphere averages 4% or anywhere near that is ridiculous. All the reputable sources I can find agree that 4% is an extreme that occurs or is exceeded only in the hottest part of the day in the warmest and most humid regions of the earth. The average is much less than that.

[_canpakes]

Actually when the atmosphere is supersaturated with humidity, the atmosphere can hold up to 10% H2O. The ceiling isn't 4%. And given that 72% of the world is covered with oceans, it is more likely than not that the air above that water is saturated by 4% or more with H2O.

Tobin, you imply that air above water must always be at that 4% level. Then you must assume the same for any area covered by snow, but that example alone disproves your claim, even before we begin to examine percentage at a given height above ground (or water).

Anyhow, actual scientists have already looked at this issue and none agree with your claim that 4% is the average, or even close to average.

http://earthobservatory.nasa.gov/Global ... 2_M_SKY_WV

You've been tossing some claims out here and there about religious fanaticism. It should be noted that this label sticks well to folks who believe things that have no basis in fact. This category includes your statements here about water vapor content of the atmosphere, given that you have provided no reference to back it up.

[_Tobin]

Brad,

I wasn't the one claiming that 4% was the maximum saturation point for water vapor in air. Obviously that isn't true.

[_Res Ipsa]

Brad,

I wasn't the one claiming that 4% was the maximum saturation point for water vapor in air. Obviously that isn't true.

If you think that's been my claim, you've misunderstood. I've said several times that 4% represents fully saturated air at around 86 degrees. Your chart confirms that.

I've also referred to sources that describe the water vapor content of the atmosphere as ranging from 0% to 4%, depending on local temperature and relative humidity.

My actual claim is that your claim that water vapor is 4% of earth's atmosphere is absurd.

[_Res Ipsa]

Actually when the atmosphere is supersaturated with humidity, the atmosphere can hold up to 10% H2O. The ceiling isn't 4%. And given that 72% of the world is covered with oceans, it is more likely than not that the air above that water is saturated by 4% or more with H2O.

Tobin, you imply that air above water must always be at that 4% level. Then you must assume the same for any area covered by snow, but that example alone disproves your claim, even before we begin to examine percentage at a given height above ground (or water).

Anyhow, actual scientists have already looked at this issue and none agree with your claim that 4% is the average, or even close to average.

http://earthobservatory.nasa.gov/Global ... 2_M_SKY_WV

You've been tossing some claims out here and there about religious fanaticism. It should be noted that this label sticks well to folks who believe things that have no basis in fact. This category includes your statements here about water vapor content of the atmosphere, given that you have provided no reference to back it up.

Tobin's post here shows he doesn't know what he's talking about. He is mixing up ordinary saturation, which has a limit at a specific temperature, with supersaturation, which can occur under specific circumstances. For his claim to be true, the air temperature above all the oceans must be at least 86F.