If water vapour is the worst greenhouse gas, is the water vapour from nuclear plants bad for global warming?

Question

I was reading http://www.greenhouse.gov.au/education/factsheets/what.html. Seeing as power plants emit so much water vapour, is the emissions worse than carbon emissions?

Answer 1

No one knows for sure. Water vapor accounts for around 60-70% of the greenhouse effect. The link you provide has some nice propaganda stating that CO2 is responsible for 70% of the "enhanced" greenhouse effect. My assumption is that "enhanced" means the amount of the greenhouse effect that is above normal. Whatever the case, CO2 accounts for a small percentage of the greenhouse effect overall.

The problem with water vapor is that it is part of a positive feedback loop. The greenhouse effect causes the atmosphere to warm which in turn allows the atmosphere to hold more water vapor. With more water vapor, the greenhouse effect increases which allows the atmosphere to hold even more water vapor.

The interesting fact is that with more water vapor, there will be more clouds which reflect sunlight back into space which can cause cooling.

Again, no one knows for sure how increased water vapor will affect global warming. What would happen if we converted much of our CO2 emissions to water vapor emissions? For all we know, we could greatly accelerate global warming.

And that is the problem with the global warming alarmism. Sure the planet is warming (.7 degree C in 100 years), but no one knows the exact reasons. The alarmists have largely ignored water vapor because man has little to do with water vapor. Yet, they are ignoring the biggest factor in the greenhouse effect.

EDIT - Water vapor doesn't stay in the atmosphere?!? The nice folks in Florida, Georgia, Alabama, Mississippi, Louisiana, much of Texas, and many, many other areas of the world would strongly disagree. And to think I though humidity is water vapor...

Answer 2

Water vapor is indeed a greenhouse gas, and more water vapor in the atmosphere causes the atmosphere retain more heat. But what is causing water vapor to increase in the atmosphere? Water vapor increases due to warmth. Warming causes more evaporation, more water in the atmosphere. It is a feedback to whatever causes the initial warming. While water vapor is a stronger greenhouse gas than CO2 it only stays in the atmosphere for a few days whereas CO2 stays in the atmosphere for hundreds of years. If the atmsophere were to cool a little, the amount of water vapor will decrease in just a few days and amplify the cooling. Likely, warming from CO2 causes more water vapor which amplifies the warming. The water vapor feedback increase the effect of CO2 by at least 2x and as much as 4x when the interaction with other feedbacks is considered. If global warming is a hoax, you should be very very alarmed because it means that all of the greatest scientists in the world are in a big conspiracy against all of the people of the world. It means there is no science that we can trust because all of academia and all the publishers of science journals are in on the conspiracy. It means that all technological development is crashing to a stop because the whole scientific method is a fake. The link below is to a paper that discusses the climate feedbacks to CO2 from the Journal of the American Meteorological Society.

Answer 3

I don't agree that water vapor is the "worst" greenhouse gas. It "forces" warming as a gas, but spends only part of it's time as a gas. Supposedly this is related to the "tipping" point.

The earth was believed to have been quite warm originally. Most of the water we have now was here, but all in the form of gas in the atmosphere. Rain fell, but instantly evaporated. Slowly the land cooled, until at some point, the rain that fell no longer evaporated and the accumulation of liguid water in the low places began. The seas absorbed more heat from the crust and sent it off into the atmosphere by evaporation, cooling the crust a little more. Whenever it got cool enough life evolved in the seas, including plants. The plants removed most of the CO2 from the air. CO2 on earth never takes liquid or solid form as it does on Mars and some other planets. This was a huge change. Without the CO2 or the high level of water vapor the atmosphere was more transparent and more of the sunlight was reflected into space, cooling things much more. At the point where it became cool enough, ice began to form. Because ice is very reflective, even more of the Sun's energy was reflected back into space, and things cooled a little more.

We've stayed in that condition ever since with minor fluctuation. The highest temperature since is thought to have been th 8 degree rise at the end of the Permian era. That killed all life on land, and almost all in the seas.

My opinion is that the real point of no return is the point where water can't exist as a liquid. We're a long way from that, and frankly, I doubt that we'll ever reach it. There will be an earlier point where life can't exist, and one earlier still where people can no longer influence things. So the relevant questions would appear to be whether without the human contribution of tCO2 and other gases the warming trend will reverse, and whether or not that comes before our extinction. There is no way to determine either. Human CO2 production is controlled by politics, and therefor so is the order of these events.

Answer 4

Hey! That's True! You got a point here! totally missed.
Thanks.
But, there is a confusing aspect about Water Vapor.
You see, the atmosphere can hold only so much water vapor and it already does, it always has all the vapor it can hold.
.
It is possible to locally or temporarily increase the water in the air until the air looks like steam, you know, like clouds.

But, there is a limit and that average limit was reached shortly after the oceans formed, for this reason, nuclear powerplants, notoriously wasteful in energy, will make matters worse in terms of heat energy that heats up the air and temporary concentrations of clouds (lets ignore that the clouds are white and reflect sun heating better than the ground, it is more confusing than significant),

The energy waste of nuclear powerplants means that they put into the air three times, or more, energy for EACH Kilowiatt produced than oil powerplants.
The reason is that the steam in Atomic plants reaches a maximum of about a third the temperature of in oil burning powerplants, this means far more than three times the energy used is wasted into the air (the energy conversion efficiency goes up with temperature).
This is DIRECT Global Warming. In the long term, nuclear power, even if they never had an accident, will not let humanity survive..

When the temperature of earth was higher, the amount of water in the air was higher. And, so it will in the future, which will increase Global Warming. That is another "Tipping Point".

When the amount of water vapor is too much to stay in the air, because the air is too cold, say due to air currents moving the vapor to Antarctica and the air reaches very low temperatures, then the vapor comes down like rain water or snow ice and that is why the ice thickness in Antarctica is increasing while the ice in Greenland melts away. Both are increasing in temperature but Antartica has more snowfall.

Small point, yes Water vapor is worse than Carbon Dioxide but Methane is eight (8) times worse and the oceans have not tons of it but GIGAtons of it. They are in a frozen solid state, they look like gravel, but if they ever come out of solution, well, how can one put it delicately.

Imagine the ovens in Auschwitz, something like that, with our grand children inside. And all because we were all from Missouri, the "Show Me!" State, except we don't have time to study, investigate and learn. We want somebody we trust to tell us what to believe. Like who? Like mother or father. But, do they know? Is it their problem to learn and teach us?

Maybe all we need to know is that as the temperature increases the water vapor goes to the top of the atmosphere and gets blown away by the solar wind, that is what happened in Venus, its atmophere is now Carbon Dioxide at a temperature of 846 deg. Fahrenheit. Warmer than a hot oven.

Answer 5

H2O in the atmosphere very rapidly reaches an equilibrium with liquid H20 on land. The "residence time" of H20 in the atmosphere is very short, compared to CO2.

That means, in terms of _changing_ temperature in the short term (global warming) CO2 is way more important. The scientific jargon is that H2O is not a climate "forcing" factor and CO2 is. More here:

http://environment.newscientist.com/channel/earth/climate-change/dn11652

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

5_for_fighting. You're close, but not there. Read the links above.

Answer 6

I don't see water vapour being the problem it is the carbon dioxide in the atmosphere. Water vapour is part of the water cycle of our planet and has been doing it for millions of years.

Answer 7

No.

Atmospheric water vapor concentrations are dependent upon the atmospheric temperature. A hotter planet makes a hotter atmosphere which holds more water vapor. You need something else (i.e. CO2) to increase the global temperature in order for there to be more atmospheric water vapor.

Answer 8

water vapor from what i understand is homeostatic and less of a concern than carbon dioxide. that is, an average of water vapor will always be in the atmosphere where as CO2 is increasing.
also, water vapor doesn't hang out in the troposphere which is where i guess the heat gets trapped.
-edit-, im sorry, i think i meant the thermosphere...

Answer 9

Short answer is no.

Long answer is that the natural process that removes water vapor from the air (rain) increases if the level of water vapor increases. Unfortunately the natural processes them remove CO2 from the air (biological and geological processes like plants growing and subduction) do not seem to be as responsive to increasing CO2 levels.

Answer 10

No. Water vapor doesn't remain in the atmosphere--unlike CO2, it condenses out. If the water vapor did remain in the atmosphere, it would be a problem.