Manmade humidity causes global warming

[rfkrfk]

I feel like starting a flamewar.

The biggest contributor to the greenhouse effect
is water vapor.
Human activity can increase atmospheric water vapor, in some areas.
For example, the Colorado River does not reach the ocean.
All of it goes into the air, in a formerly low-humidity place.
Something similar, for the places downwind of the
big manmade lake on the Nile River.
Just after 9/11, due to reduced air traffic, nightime temp drops, increased.
Etc, etc, etc.
Manmade humidity, is what I call,
temporary in theory, but permanent in practice.

[NNadir]

1. Man made humidity is caused by nuclear power plants.

Everyone has seen a picture of a cooling tower.

[IADEMO2004]

2. Sleep at night. No Art Bell

[Dogmudgeon]

3. Heat plus water equals water vapor

That's been known for decades, and the increase in atmospheric water has been logged for well over ten years.

During Ice Ages, water is condensed out and often ends up in the form of snow and ice.

What's to flame?

--p!

[leftstreet]

4. Nothing to flame here. We've got moss in a formerly arid part of state

Major, major corporate agriculture all around us.

Moss, SLUGS!, humid summers. Unheard of in the past.
And the difference between 100 degree temps in an arid vs humid climate?
UNBEARABLE!

[rfkrfk]

5. people attribute all of global warming to CO2 increase,

yet,
when I pose a question like...
if atmospheric CO2 goes from 300 to 400 ppm,
how much does that change the opaqueness of the atmosphere?,
nobody knows

[jpak]

19. They do know....

and it's old news...

http://www.eurekalert.org/pub_releases/2001-03/ICoS-Fdoe-1403101.php

First, direct observational evidence of a change in the Earth's greenhouse effect between 1970 and 1997

Scientists from Imperial College, London, have produced the first direct observational evidence that the earth’s greenhouse effect increased between 1970 and 1997.

Writing today in the journal Nature (1), researchers in the Department of Physics show that there has been a significant change in the Earth’s greenhouse effect over the last 30 years, a finding which is consistent with concerns over so-called ‘radiative forcing’ of the climate (2).

Previous studies in this area have depended on theoretical simulations because of the lack of data. However the Imperial team reached their conclusions after analysing data collected by two different earth-orbiting spacecraft, in 1970 and 1997.

Comparison between the two data sets has unequivocally established that significant changes in greenhouse gas emissions from the Earth have caused the change to the planet’s greenhouse effect over this time period.

<more>

[Dead_Parrot]

6. It's a valid question...

The largest source of water vapor is evaporation from the oceans: This should not surprise anyone.
Water evaporates more in warmer conditions: This should not surprise anyone, either.
It doesn't take a giant leap of logic to realise that oceanic water vapour is therefore one of the key positive feedback mechanisms: The warmer it gets, more evaporation there is, and the warmer it gets.

The question of how much water vapour gets into the air directly from human interference is an interesting one, but if you look at the comparitive sizes of the sources (ocean area vs river area) you'll see it is tiny: The daily evaporation/precipitation of water - about 1,150 km3 - is over half the total water in all the worlds rivers (2,120 km3) and the Colorado's daily flow of ~0.075 km3 pales into not very much at all, accounting for 0.0065%.

I don't have the GH-effect figures for water vapour to hand, but I assume a 90% increase in co2 is more significant than a 0.0065% increase in water vapour (although neither is a very good idea). If anyone wants to throw figures for the nile evaporation et al, please go ahead... :)

[rfkrfk]

7. look at this pic...

http://antwrp.gsfc.nasa.gov/apod/ap041013.html

then tell me, that water vapor from human
activity is not changing anything


Nile river, I would assume that more than half of the yearly flow,
does not reach the Mediterranian.

We are putting water vapor, where it
ain't suppose to be.

International jet fuel tax, zero, not one penny
jet fuel for domestic flight {US}, four cents a gallon .
not a typo, 4 cents

[Dead_Parrot]

8. OK: Water vapor from human activity is not changing anything.

Well, I didn't actually say that, but I was trying to point out he effect is negligible.

Contrails (unless you have a tin-foil hat on) are caused by turbulent shock coalescing water vapor into water droplets: no water vapor is actually added, it's just made visible. Here's a nice photo to illustrate it:



You will see that the visible vapor is forming just off the wingtips. The air behind contains as much H2O as the air in front, but now you can see it - that's all.

As for the Nile, dig out the flow rate in km3 and compare it to global evaporation, as I did for the colorado. It's not not much, percent-wise.

And yeah, 4c/gallon is dumb.

:)

[rfkrfk]

9. don't confuse, two different effects

that have a similiar appearance

a 'normal' condensation trail is the result of the condensation
of the water vapor in engine exhaust, the issue
being --> water is added

but, it looks similiar to,
what I call 'vacuum induced' contrail,
usually coming from a wing or propellor tip,
where there is no added water

total ocean evaporation is not meaningful,
adding water to a rainforest, does not change anything,

OTOH, I content that adding water to a desert or
the upper atmoshere, where it was previously dry,
does change something

http://www.nasa.gov/home/hqnews/2004/apr/HQ_04140_clouds_climate.html

[Dead_Parrot]

10. Well, I hestitate to argue with NASA, but...

Yes, aircraft exhaust does contain H20, but it is not a significant amount compared to evaporation. Certainly, water in aircraft is not coming out in visible drops of water - find a picture of a plane taking off (when the engines are at maximum) and point out the visible steam billowing out of the back: I've never seen it.

As for the report, they cheefully admit that the temperature rose after 9/11, which is the exact opposite of of thier predictions: I'm an old fashioned sort of scientist, and when the results don't match the theory I reckon I've got my theory wrong.

what "total ocean evaporation is not meaningful" means I have no idea, could you expand that a little? Thanks.

[rfkrfk]

12. my central contention is...

that human activity is adding water vapor,
to 'unsaturated' areas,
such as, the leeward side of the US Rockie Mountains, or,
the upper troposphere {where jet aircraft cruise],

suppose water evaporates, and falls in the Congo river basin.
... that amount is {poor choice of words on my part} meaningless,
as the area has 100% humidity, all the time, anyway

OTOH, my conjecture is, if human activity changes the humidity
in Death Valley from 5 to 10 percent, you have changed something

concerning 9-11, the reason temps went back to 'normal' {up,as you put it]
is that temps went down, for one day, the went back to
'normal', as flight activity resumed

[Dead_Parrot]

22. I still don't see it.

I'm happy to accept that we're artifically increasing humidity in certain areas like Death Valley, but again I can't see this as significant in regards to global climate change - The percentage of added h20 is simply too small. It may well have a localised impact, but only in the lowest zones.

Likewise, adding tiny quantities to the upper troposphere is not going to have an impact, as the area has normal evaporated water cycling through it anyway (This is the region where cirrus clouds form, even without our help). It seems more likly to me that contrails would lower the temperature by increasing the albedo.

If we were adding lots of H2O to the stratosphere then we might well have an issue, since it doesn't mix much and the water would stay there for some time, but this isn't the case.

I'm going to have to do some more digging on the 911 effect, as the daytime increase is offset by a corresponding nighttime decrease (so it might be something else altogether). I'll let know if I work it out :)

[OneBlueSky]

11. hot air from Washington is the greatest cause of global warming. . . n/t

.

[megatherium]

13. I've become concerned about global oxygen depletion.

As the CO2 levels in the atmosphere increase from 300 ppm to 400 ppm this century, this means the oxygen level will decrease from 190,000 ppm to 18,900 ppm. At this rate, in 10,000 years, the oxygen in the atmosphere will drop to below 180,000 ppm. This will cause profound effects on world ecosystems. For example, I would expect the alpine zones will drop in elevation on the world's mountain ranges.

[jpak]

20. Can't happen

Oxygen accumulates in the atmosphere due to the burial of organic matter in marine sediments.

There is a huge amount of organic matter in sedimentary rocks, but only an insignificant fraction is present as fossil fuels.

If humans burned every speck of oil and coal and natural gas on the planet, atmospheric oxygen concentrations would not decline appreciably.

Scientists have measured a decrease in atmospheric oxygen commensurate with the oxidation of fossil fuels. It was very difficult to do as they had to measure a very small change in oxygen relative to a very big pool....

[megatherium]

21. There is a famous article, "National Geographic:

Doomsday Machine" that appeared in the Journal for Irreproducible Results. It argued that the crust of North America would buckle because of the relentless accumulations of this magazine, which no one throws out. This was followed in a subsequent issue by an article carefully refuting the first article.

Cheers!

[Viking12]

14. For your reading pleasure

Water vapour: feedback or forcing?

Whenever three or more contrarians are gathered together, one will inevitably claim that water vapour is being unjustly neglected by 'IPCC' scientists. "Why isn't water vapour acknowledged as a greenhouse gas?", "Why does anyone even care about the other greenhouse gases since water vapour is 98% of the effect?", "Why isn't water vapour included in climate models?", "Why isn't included on the forcings bar charts?" etc. Any mainstream scientist present will trot out the standard response that water vapour is indeed an important greenhouse gas, it is included in all climate models, but it is a feedback and not a forcing. From personal experience, I am aware that these distinctions are not clear to many, and so here is a more in-depth response (see also this other attempt).


First some basics. Long-wave (or thermal) radiation is emitted from the surface of the planet and is largely absorbed in the atmosphere. Water vapour is the principle absorber of this radiation (and acknowledged as such by everybody). But exactly how important is it? In terms of mass, water vapour is much more prevalent (about 0.3% of atmospheric mass, compared to about 0.06% for CO2), and so is ~80% of all greenhouse gases by mass (~90% by volume). However, the radiative importance is less (since all molecules are not created equal). One way to quantify this is to take a radiation model and remove each long-wave absorber (principally the greenhouse gases, but also clouds and aerosols) and see what difference it makes to the amount of long-wave absorbed. This gives the minimum effect from each component. The complementary calculation, using only each particular absorber in turn, gives the maximum effect. Generally these will not be equal because of overlaps in the absorbing spectra (i.e. radiation at a particular frequency can either be absorbed by water vapour or CO2).


http://www.realclimate.org/index.php?p=142

Busy Week for Water Vapor

It's been a busy week for water vapor, and I have two recent papers to discuss. The first is the paper "Anthropogenic greenhouse forcing and strong water vapor feedback increase temperature in Europe" by Rolf Philipona et al. (GRL, 2005, subscription required for full text), which has attracted a certain amount of media attention. The overall goal of the paper is to understand, from a physical standpoint, why European temperatures have been increasing three times faster than the Northern Hemisphere average. It focuses on the changes between 1995 and 2002, over which time good surface radiation budget observations are available. The paper reports some results on the role of large scale circulation changes (which they conclude are minor) but I'll concentrate on the results relating to water vapor.

http://www.realclimate.org/index.php?p=212

[phantom power]

15. So... In 25 words or less....

Although water vapor does indeed dominate the greenhouse effect in our atmosphere, it also acts as an amplifier of any other GHGs, due to it's tendency to maintain relative humidity. A small increase in something like CO2 raises temperatures a small amount, but then water vapor also rises in response to that increase, and so adds it's own increase in temps. It amplified the effect of the CO2. The upshot is that the atmosphere, as a system, is indeed sensitive to the CO2, methane, etc, that we add to it.

Now, if I understood those writeups, the climatologists are still working out exactly why the atmosphere tends to maintain it's relative humidity, however both experimental measurements and their models show this effect, and so for whatever reason, they feel confident that it's a real phenomenon.

[Viking12]

16. Hey, that's more than 25 words :)

But a nice summary anyways :toast:

[phantom power]

17. "Can I have 55 words with you..."

[jpak]

18. Horse shit and pseudoscience

Water vapor exists in the atmosphere due to the presence of greenhouse gases.

If all GHG were removed from the atmosphere, water vapor would quickly be removed by precipitation, deposited as snow, and the Earth would become cold, dry and nearly lifeless (think Mars, and Neoproterozoic Snowball Earth).

http://www-eps.harvard.edu/people/faculty/hoffman/snowball_paper.html

Increases in GHG concentrations increase the mean temperature of the atmosphere and the amount of water vapor in the atmosphere.

http://news.bbc.co.uk/2/hi/science/nature/4419880.stm

It's a positive feedback in either direction.