Sentences with phrase «if water vapor feedbacks»

Sure, there might be a few papers that take climate sensitivity as a given and somehow try to draw conclusions about the impact on the climate from that... But, I hardly think that these are swamping the number of papers trying to determine what the climate sensitivity is, studying if the water vapor feedback is working as expected, etc., etc..

When the authors of the paper looked at their general climate models, they discovered that, once they corrected for an El Nino that occurred right after Pinatubo erupted, the model only produced roughly equivalent cooling if water vapor feedback was included in the model (Figure 4, to the right).

Not exact matches

If a positive feedback amplifies a signal, and the resulting change attributable to water vapour feedback is greater than the initial signal, then any further perturbations will be competing with the change attributable to water vapor.

[1] CO2 absorbs IR, is the main GHG, human emissions are increasing its concentration in the atmosphere, raising temperatures globally; the second GHG, water vapor, exists in equilibrium with water / ice, would precipitate out if not for the CO2, so acts as a feedback; since the oceans cover so much of the planet, water is a large positive feedback; melting snow and ice as the atmosphere warms decreases albedo, another positive feedback, biased toward the poles, which gives larger polar warming than the global average; decreasing the temperature gradient from the equator to the poles is reducing the driving forces for the jetstream; the jetstream's meanders are increasing in amplitude and slowing, just like the lower Missippi River where its driving gradient decreases; the larger slower meanders increase the amplitude and duration of blocking highs, increasing drought and extreme temperatures — and 30,000 + Europeans and 5,000 plus Russians die, and the US corn crop, Russian wheat crop, and Aussie wildland fire protection fails — or extreme rainfall floods the US, France, Pakistan, Thailand (driving up prices for disk drives — hows that for unexpected adverse impacts from AGW?)

I wonder what would happen if the same approach was applied to other climate metrics, like sea surface temperature, water vapor feedback strength, and precipitation - evaporation changes.

If the CO2 rise is a carbon cycle feedback, this is still perfectly compatible with its role as a radiative agent and can thus «trigger» the traditional feedbacks that determine sensitivity (like water vapor, lapse rate, etc).

(PS regarding Venus — as I have understood it, a runaway water vapor feedback would have occured when solar heating increasing to become greater than a limiting OLR value (Simpson - Kombayashi - Ingersoll limit — see http://chriscolose.wordpress.com/2010/08/23/climate-feedbacks-part-1/ — although I should add that at more «moderate» temperatures (warmer than today), stratospheric H2O increases to a point where H escape to space becomes a significant H2O sink — if that stage worked fast enough relative to solar brightening, a runaway H2O case could be prevented, and it would be a dry (er) heat.

BUT that if we continue to add CO2 to the air, the air has the added heat capacity to get warmer, IF and ONLY IF driven by the sun, but rapidly come to equilibrium with the ocean, by means of rain and the daily heating & condensation of the water vapor feedback mechanisif we continue to add CO2 to the air, the air has the added heat capacity to get warmer, IF and ONLY IF driven by the sun, but rapidly come to equilibrium with the ocean, by means of rain and the daily heating & condensation of the water vapor feedback mechanisIF and ONLY IF driven by the sun, but rapidly come to equilibrium with the ocean, by means of rain and the daily heating & condensation of the water vapor feedback mechanisIF driven by the sun, but rapidly come to equilibrium with the ocean, by means of rain and the daily heating & condensation of the water vapor feedback mechanism.

If a doubling of CO2 resulted in a temperature increase of approximately 1 K before any non-Planck feedbacks (before water vapor, etc.), then assuming the same climate sensitivity to the total GHE, removing the whole GHE would result in about a (setting the TOA / tropopause distinction aside, as it is relatively small relative to the 155 W / m2 value) 155/3.7 * 1 K ~ = 42 K. Which is a bit more than 32 or 33 K, though I'm not surprised by the difference.

16 (DBB) If more water vapor leads to more precipitation then water vapor will act as a negative feedback on rising global temperature.

Re 9 wili — I know of a paper suggesting, as I recall, that enhanced «backradiation» (downward radiation reaching the surface emitted by the air / clouds) contributed more to Arctic amplification specifically in the cold part of the year (just to be clear, backradiation should generally increase with any warming (aside from greenhouse feedbacks) and more so with a warming due to an increase in the greenhouse effect (including feedbacks like water vapor and, if positive, clouds, though regional changes in water vapor and clouds can go against the global trend); otherwise it was always my understanding that the albedo feedback was key (while sea ice decreases so far have been more a summer phenomenon (when it would be warmer to begin with), the heat capacity of the sea prevents much temperature response, but there is a greater build up of heat from the albedo feedback, and this is released in the cold part of the year when ice forms later or would have formed or would have been thicker; the seasonal effect of reduced winter snow cover decreasing at those latitudes which still recieve sunlight in the winter would not be so delayed).

If C02 is the largest single contributing factor to the Greenhouse Effect (because supposedly water vapor is only involved as a feedback to primary chemistry involving C02 itself), and C02 lags temperature increases (as has been stated on this very blog), how has the Earth ever returned to colder glacial conditions following periods of warming?

If CO2 in the Anthropocene atmosphere contributes to re-vegetating currently arid areas as it did post-LGM, we should expect an even greater warming feedback from CO2 than is assumed from water vapor and albedo feedbacks, due to decreased global dust - induced albedo and increased water vapor from transpiration over increased vegetated area.

It's hard to see how water vapor could be a negative feedback if 1) water vapor is a greenhouse gas (undeniable); and 2) water vapor increases with temperature (supported by theory and observations).

If water vapor is an exclusively positive feedback for warming, we would not currently be in an ice age, nor ever would be again.

Changing concentrations of CO2 will impact the temperature and if it is an increase the positive feedback of drawing out more water vapor will contribute to the average climate getting warmer.

If, for instance, CO2 concentrations are doubled, then the absorption would increase by 4 W / m2, but once the water vapor and clouds react, the absorption increases by almost 20 W / m2 — demonstrating that (in the GISS climate model, at least) the «feedbacks» are amplifying the effects of the initial radiative forcing from CO2 alone.

''... the warming is only missing if one believes computer models where so - called feedbacks involving water vapor and clouds greatly amplify the small effect of CO2.»

Water vapor is the major greenhouse gas and helps to warm the Earth if temperatures are below the «equilibrium» level (thermostat temperature)-- so called positive feedback.

If you're like many skeptics and think that the water vapor feedback is spurious, then you're saying that the air will be drier.

If there was no greenhouse effect or if something were to block it any doubling of carbon dioxide would yield zero degrees warming and the water vapor feedback likewise would be zero, giving a climate sensitivity of exactly zero for this doublinIf there was no greenhouse effect or if something were to block it any doubling of carbon dioxide would yield zero degrees warming and the water vapor feedback likewise would be zero, giving a climate sensitivity of exactly zero for this doublinif something were to block it any doubling of carbon dioxide would yield zero degrees warming and the water vapor feedback likewise would be zero, giving a climate sensitivity of exactly zero for this doubling.

But, if the atmosphere in the polar regions warms there will be more evaporation and thus a postive feedback from greenhouse effect of increased water vapor.

IF, water vapor feedback were 2 time CO2 forcing, it would have been a useful assumption.

If one argues that water vapor acts primarily as a feedback, you are also arguing that carbon dioxide is truly inconsequential.

One such feedback might exist if, as assumed in some models, relative humidity is constant, so increasing the temperature has the positive feedback of increasing the water vapor.

28 Estimated Strength of Water Vapor Feedback Earliest studies suggest that if the absolute humidity increases in proportion to the saturation vapor pressure (constant relative humidity), this will give rise to a water vapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute humiWater Vapor Feedback Earliest studies suggest that if the absolute humidity increases in proportion to the saturation vapor pressure (constant relative humidity), this will give rise to a water vapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute humiVapor Feedback Earliest studies suggest that if the absolute humidity increases in proportion to the saturation vapor pressure (constant relative humidity), this will give rise to a water vapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute hFeedback Earliest studies suggest that if the absolute humidity increases in proportion to the saturation vapor pressure (constant relative humidity), this will give rise to a water vapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute humivapor pressure (constant relative humidity), this will give rise to a water vapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute humiwater vapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute humivapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute hfeedback that will double the sensitivity of climate compared to an assumption of fixed absolute humidity.

So let me ask you if water vapor is a positive feedback, what is the effect of increasing temperature at top of atmosphere?

RG to Kim...» If you think water vapor feedback is incorrect, create the maths to take it out of the models and send your suggestion to NCAR in Boulder.»

If this is natural, so if a «warming regime» (the word choice may indicate bias, by the way) is changed unforced into a cooling regime you may very have proven that a positive feedback mechanism due to water vapor is impossiblIf this is natural, so if a «warming regime» (the word choice may indicate bias, by the way) is changed unforced into a cooling regime you may very have proven that a positive feedback mechanism due to water vapor is impossiblif a «warming regime» (the word choice may indicate bias, by the way) is changed unforced into a cooling regime you may very have proven that a positive feedback mechanism due to water vapor is impossible.

Warmist Sez: «If you think water vapor feedback is incorrect, create the maths to take it out of the models and send your suggestion to NCAR in Boulder.»

If you think water vapor feedback is incorrect, create the maths to take it out of the models and send your suggestion to NCAR in Boulder.

If water - vapor provides positive feedback at low absolute - humidity levels and negative feedback at high humidity levels, you have an explanation.

Miskolczi's argument (I think) is that CAGW proponents have to be out to lunch if they can believe water vapor is a negative temperature feedback EXCEPT when temperature rise is caused by CO2, in which case it magically becomes a positive feedback.

The only sense in which your argument for a negative water cycle feedback makes much sense is if you are grouping together cloud and water vapor effects in such a feedback (which I guess is not unreasonable when you refer to it as «water cycle» but becomes confusing when you refer to it as «water vapor feedback»).

Of course, warming from solar forcing (or reduced aerosols) would tend to increase the total convection even if the LW water vapor feedback is saturated at the surface (not the same as saturated at the tropopause or TOA).

If so then is there no such thing as feedback from added water vapor?

In other words, if I increase substance X by 1 % in the atmosphere, what is the effective change in radiative forcing (or temperature), either with or without water vapor feedbacks?

In light of trends showing a likely 3 °C or more global temperature rise by the end of this century (a figure that could become much higher if all feedback processes, such as changes of sea ice and water vapor, are taken into account) that could result in sea level rises ranging from 20 to 59 cm (again a conservative estimation), Hansen believes it is critical for scientists in the field to speak out about the consequences and rebuke the spin offered by pundits who «have denigrated suggestions that business - as - usual greenhouse gas emissions may cause a sea level rise of the order of meters.»

The units are irrelevant; the bottom line is that the IPCC's conclusions about water vapor feedback would be grossly incorrect if the old radiosonde data were correct.

If that problem could be solved, it would provide the longest record of water vapor feedback driven by the largest change in temperature.

If the models have similar assumptions wrt water vapor feedback, then the model accuracy rests on the accuracy of such assumptions.

But there has been at least one time where I brought up the amplification carbon dioxides» effect by water vapor, and if I didn» explain that the feedback had feedback, that became an issue for someone else — and I was trying to avoid that aspect of it.

But one thing all aerosols have in common is that if you are going to balance the greenhouse effect due to increasing levels of carbon dioxide, you must keep increasing the amount of aerosols — which will then increase the negative effects associated with them — including diminished agricultural output and climatic side - effects — as they will not evenly counteract the effects of increased carbon dioxide and its water vapor feedback due to evaporation.

But I do not see any simple way to verify the no - feedback sensitivity; if you include evaporative cooling from the ocean surface (for example), then you immediately get into the feed - back issues of water vapor and cloud cover.

The IPCC attributes ACO2 as being the forcing agent, F, for this scenario, with water vapor the feedback, f, and temperature, t, the parameter for the change; the interaction of these variables is measured by the state vector, S, which would itself change if F has the effect the IPCC alleges.