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Water Vapor Causing Climate Warming
karvind writes "According to BBC, new studies suggest that water vapor rather than carbon dioxide in the atmosphere is the main reason why Europe's climate is warming. The scientists say that rising temperatures caused by greenhouse gases are increasing humidity, which in turn amplifies the temperature rise. This is potentially a positive feedback mechanism which could increase the impact of greenhouse gases such as CO2. Even though 2005 will probably be warmest year, climatologists still differ in opinion"
Too bad we wont be able to say "At least it's a dry heat" if this continues.
I could be missing something, but isn't this basic astronomy (or whatever science you care to term it)? Water vapor (among other gasses) is responsible for keeping a planet heated, and not a frozen ball of rock like Mars. Maintaining that delicate balance of how much water is in the air is important of course, but noting that water is causing the atmosphere to retain heat is... nothing new.
-Daniel
Scientists promptly advised everyone to:
1. Stop drinking water
2. Stop breathing
3. Stop taking showers (note: this doesn't apply to some countries such as France and Mexico)
Warming starts with CO2 and other greenhouse gases. Warmer climate means more evaporated water in the atmosphere. Guess what? Water vapor is also a greenhouse gas. So climate gets warmer. Lather. Rinse. Repeat.
This isn't a story that undermines or changes the prevailing scientific view. This may allow some fine tuning of the models. Some skeptics had argued with the results of the models because they didn't believe the contribution of water vapor. This may force them to reevaluate their view. (Yeah right).
The reason we don't know how much global temperatures are going to rise is because we don't know enough about water vapor. Water vapor is thousands of times more potent than man made greenhouse gas. The main reason we can't 100% accurately predict the temperature is because we don't know for sure where the water vapor goes in the atmosphere. However, that does not mean that water vapor is causing global warming. Human emissions are the reason why there is more water vapor in the air than ever before. This isn't really knew, mainstream science has known this for ten plus years.
Accepted facts about global warming are as follows:
a)We are putting more greenhouse gases into the air than ever before.
b)Greenhouse gases trap heat.
c)The earth is getting warmer.
No one disagrees on these facts. The only legitamite disagreement is on how much warmer the earth will get, and this is because we don't know where the water vapor sits in the atmosphere. Supercomputers estimate the temperature increase will be between 1.5 and 11 degrees celcius in the next 50 years. At the low end we are seriously screwed. At the high end it is the end of civilization as we know it.
Assuming this your post wasn't completely tongue-in-cheek...
So, in order to "mine" the water vapor out of the atmosphere, you would need some way of condensing the vapor. Any sort of heat exchanger would work, but the laws of thermodynamics dictate that, in the end, you would just be heating the atmosphere up more than accomplishing anything else. This does assume that the control volume for the system is the earth itself, and you're not using space as your 'cold reservoir'--doing that gets into all sort of pesky heat transfer issues as space is rather non conductive. There is something to be said for radiation, but it would only really be effective if shielded from the sun. Anyway, since the most likely mediums for heat rejection would probably be either the atmosphere (you lose), the ocean (you lose again), or the terrestrial bits of the earth (you lose still), all you would be doing it heating the atmosphere up more and putting more water vapor into the atmosphere in the long run.
If your toast does not accquire any kind of royalty, please do not contact us. We can't help you.
(Hopefully) before this ends up in a big pissing match over whether or not global warming is real, I'd like to lay down some ideas.
Our climate changes- it has for billions of years and it will for billions of more years.
Our climate is *incredibly* complex, so accurate prediction either way is nigh impossible (and I think it's arrogant to imply we know enough about our climate to even try to control it).
Global warming *is* happening, but factually only in the sense that our planet has been getting warmer- the debate is over whether or not man is to blame. Keep in mind, we just came out of an ice age several thousand years ago, so global warming is basically a given until we enter the next ice age.
There is NO consensus on whether or not man-made global warming is happening- anyone who claims to have "climatologist" friends who say it most definitely is or isn't real and that all the real scientists agree are just pulling stuff out of their ass (and it's pretty obvious, too, so don't even try to do it).
Not everyone who believes global warming is caused by man is a crazy hippy and not everyone who believes it isn't caused by man is some money-grubbing republican. It's that kind of black and white approach to this and other topics, both by the people and especially the media, that has trivialized the issue at hand.
Please try to keep this in mind.
-Moses
I'm just curious how many scientists have looked at the possibility that the earth warms and cools in cycles
Thousands. They list glaciation, ocean variability, plate tectonics, solar variation, orbital variations, magnetic field changes, vulcanism as some of the natural causes of climate change.
And there's really not anything we can do to affect it, or stop it.
Since the industrial revolution the burning of fossil fuels has increased the amount of atmospheric carbon dioxide to about 1.5 times the level it was in the early 1800s. By 2100 we are expected to be at double the 1800s level, resulting in a temperature increase of about 2 to 5 degrees celsius. So yes, we can affect the global temperature.
:wq
I'm just curious how many scientists have looked at the possibility that the earth warms and cools in cycles,
Yes. All of them. Find an atmospheric science textbook. It's in there.
and there's really not anything we can do to affect it, or stop it.
You're asking whether atmospheric scientists, people who study the atmosphere and its behavior, think that the manner in which earth's chaotic, multi-factored atmosphere behaves over time is fixed, unchanging, and can never be effected by anything.
No, none of them think that. The cycles themselves, which are quite erratic, demonstrate that changes can happen: For one thing, the cycles obviously happen for some kind of reason. For another thing, the cycles to which you refer haven't always happened. Further back in the past the climate's cycles operated differently.
The way in which the atmospheric cycles have operated for the last 2 billion years or so-- long stable periods followed by slowly increasing, then sudden and dramtic shifts-- suggest not that climate is some preplanned externally determined thing, caused by the hand of God moving a knob on a thermostat somewhere. What they suggest is the idea of the earth's atmospheric state having a number of equilibrium points, and we are moving back and forth between those equilibrium points. This is exactly what the article slashdot links here is about-- feedback mechanisms. The idea is that as you move further away from a stable equilibrium point, positive feedback mechanisms come into play which move you further and further away from that equilibrium point, and negative feedback mechanisms which were keeping you stable at that equilibrium point shut down. Once you nudge things away from the place where they were, the more the mean temperature rises the more the mean temperature is inspired to rise further, and the more the CO2 concentration rises the more the CO2 concentration is naturally inspired to rise even further. The lesson to take away here isn't to blame the cycles; the cycles themselves need that nudge to start. The lesson to take away is, you don't want to nudge the atmosphere out of that stable state, because once you start it may be too late to nudge it back.
Irritable, left-wing and possibly humorous bumper stickers and t-shirts
But this vapor is just a feedback effect, not an atmospheric forcing. This is due to the incredibly short residence time of water in the atmosphere of ~10 days. This means that even if you could somehow instantly cause the earth to have 0% humidity everywhere, things would stabalize back to "normal" within about 20-30. True forcings like CO2 have residence time of decades, which makes them the greenhouse gas to worry about.
Everyone posting here should first read this article for the full explination. The site in general is excelent.
"You saved 1968." - Ms. Valerie Pringle to the crew of Apollo 8
"Vapor does not represent a heating, it represents a cooling."
Water evaporates when it gets hotter. The fact that more water is evaporating indicates that the Earth's system has gained heat (from the sun), even if that's stored when the water vaporizes. And water is a greenhouse gas. Much moreso, in fact, than CO2. That's presumably (without reading the article) the feedback loop.
If you check my posts you will see that I have been saying this for years.
Most of this is probably due to a lot of land at high elevation. This causes a cooling because water vapour falls out at high elevation and cannot trap the incomming solar radiation. Furthermore we get a high reflection off the snow and ice as well.
In all likelihood the cooling from the Miocene was caused by mountain building with the himalyan plateau being the latest addition. The Rockys and Andies, Pyrannies, Alps and 2 Hellenic ranges appeared before the Himalain plateau was pushed up. In North America we have the Colorado Plateau.
As part of this cooling Antarctica froze over and that locked the planet into the current snowball earth. Prior to this freeze over Antactrica was cold - but still had significant amounts of water vapour which trapped solar energy falling during the Antarctic summers. After the freeze over, Antarctica became the dryest continent on the planet - with a huge increase in the loss of solar energy falling on Antarctica. So this is a powerful positive feedback mechanizm that locked us into the current snowball earth phase.
Since then a lot of erosion has taken place which my have moved us past the equilibrium point. Still - the ice on antarctica and the glaciers at high elevation have kept us locked into the snowball earth phase.
I suspect that irrigation is causing a warming. It makes a great deal of sense. But offsetting this is the distruction of the rain forests.
CO2 is negligable. During the ordovician levels of CO2 were 13x to 19x higher than now and the earth cooled.
Some have pointed out correctly that the sun was not as strong back then. While that is true - there was a fair amount of mountain building during the ordovician (taconic orogany) and this may have been what tipped the planet from the hot house into the snowball phase. The sun was also weaker when the planet came out of the snowball phase a few million years later.
For over 80% of the last 540 million years the earth has been about 22 degrees warmer on average than now. So it makes sense that the earth will warm up - we just do not know when.
Another thing is that we have had about 22 ice cycles in the last 2+ million years and typically with a frequency of about every 100,000 years or so. 5 million years ago there were trees north of the Arctic circle in Canada. This is probably true of Russia as well.
Since we have had a number of ice cycles (the last was at peak about 50,000 years ago) it would make sense that we will have another. If so then we may be within a few 1000 years of another ice age developing.
It really will depend on where the equilibrium points are and I don't think anyone has any real idea.
One thing that is really instructive is to look at a globe of the earth that has actual mountains on it. There is one at the Tyrrell Museum in Drumheller Alberta. When you look at this globe and see just how thin the atmosphere really is - 2/3 of it lies below 30,000 feet for instance (Mount Everest) - it becomes very clear that a lot of solar incident energy is simply reflected off into space.
Get rid of the mountains and you gain a very effective H2O blanket.
In the tropics at sea level and 35C the absolute H2O vapour in the atmosphere is over 8% (80,000 ppm). This is in contrast to CO2 levels of 365 PPM.
H2O is a stronger absorber than CO2 by far - in all wavelengths.
So I frankly do not think CO2 is even a factor to be honest. The models used by the IPCC do not take into consideration that water vapour levels may be changing. When your most significant variable is not handled properly then your model isn't very believable.
From a paleoclimate standpoint - CO2 can change climate. It did several times in the Precambrian. The thing is that in order to do this the CO2 levels had to climb to many 1000 PPM. This occurred back then because so much of the earth froze over that even the oceans may have frozen r
I love how two incredibly outspoken scientists making a wager is translated here as "climate scientists differ". The fact is that climate scientists who agree that long-term anthropogenic global warming is a reality versus those who don't are in the same sort of the same sort of ratios as between biologists who believe in sevolutionist and those who don't.
And it's not a surprise. Vostok and other core data show two very telling things: 1) Global temperatures are extremely tied in to CO2 levels, and 2) barring natural catastrophes (such as major volcanic events), this is among the fastest climate changes in recorded history. You then factor in the fact that the balance of CO2 outflux to influx is computable and we're very obviously putting out CO2 faster than it can be consumed (and while higher CO2 levels increase CO2 consumption, that capability is limited), and factor in climate modelling... well, it's no real surprise that the ratios are so extreme.
He's just being nice so my real father won't freeze him in carbonite and sell him for spice.
There seem to be a few things missing in this discussion:
s .1896.climate.pdf
1. The fact that most of the warming associated
with global warming is directly forced by water
vapor is well established, going back at least
as far as Arrhenius's 1895 paper often credited
with "discovering" global warming.
(original paper at:
http://geosci.uchicago.edu/~archer/PS134/arrheniu
)
i.e. this result is CONSISTENT with our understanding
of global warming.
2. Increases in atmospheric water vapor are tightly tied
to temperature. The saturation specific humidity
(the amount of water air will hold) increases
exponentially with temperature (an implication of the
Clasius-Claperyon relationship). Thus when you increase the
temperature of the atmosphere by dT (by, for example, adding
some CO2), more water vapor evaporates into the atmosphere,
amplifying the warming.
3. This effect, known as the water vapor feedback, has been in
our climate models from the beginning (at least as far back
as 1895), and produces results consitent with observations.
4. The cited Geophysical Research Letters paper uses observations
to estimate the strength of the water vapor feedback and
finds that it is strong (even stronger than most models
predict). It is also a step in the process
of understanding climate change on a regional level.
Z
The standard argument against global warming:
1. Weather is complicated. The models aren't perfect.
2. No matter how much of a scientific consensus there may be, there will always be a few guys who don't agree.
Conclusion: We don't really know anything about climate or global warming.
Rinse, lather, repeat.
The wonderful thing about these arguments is that no matter what we may discover in the future about climate, they will remain valid (well, as valid as they are today), so you can safely trot them out any time anybody dares to suggest that you should be inconvenienced in any way to reduce global warming.
Comment removed based on user account deletion
There is NO consensus on whether or not man-made global warming is happening- anyone who claims to have "climatologist" friends who say it most definitely is or isn't real and that all the real scientists agree are just pulling stuff out of their ass (and it's pretty obvious, too, so don't even try to do it).
Well, here I go pulling stuff out of my ass (and by "my ass" I mean "the positions of the most influential bodies in the field") [my bold].
From the Position Statement of the American Geophysical Union:
Human activities are increasingly altering the Earth's climate. These effects add to natural influences that have been present over Earth's history. Scientific evidence strongly indicates that natural influences cannot explain the rapid increase in global near-surface temperatures observed during the second half of the 20th century.
From the Position Statement of the American Meteorological Society:
* The theory of how greenhouse gases directly interact with atmospheric radiation is not controversial. If no other factors counter their influence, increases in their concentration will lead to global warming.
* A steady rise in the concentration of greenhouse gases began over 200 years ago and is continuing. Atmospheric concentration of carbon dioxide, the principal greenhouse gas, has increased from pre-industrial concentrations of 280 ppmv (parts per million by volume) to over 367 ppmv in 2000, an increase of more than 30%; methane has increased from 0.7 to about 1.8 ppmv, an increase of more than 150%; nitrous oxide has increased from 0.27 to over 0.31 ppmv, an increase of 16%. Tropospheric ozone is estimated to have increased by 35% since the industrial revolution...
The first line of the National Academy of Sciences 2001 report titled "Climate Change Science: An Analysis of Some Key Questions", performed at the request of President Bush:
Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise.
In short... there is no controversy. Yes, there are a handful of very loud people who are attempting to create one, who are assisted by the media's dedication to "balance," which consists of giving equal weight to totally unequal positions. Really, though, in the scientific community, anthropogenic warming is considered to be a fact.
Now, to be clear, this doesn't mean that we should necessarily do anything about it. The existence of a phenomenon is not de facto support for any particular policy position. But let's not screw around-- the "controversy" over whether global warming is at least partially anthropogenic is manufactured and does not reflect the views of the scientific community.