Sentences with phrase «positive water vapour»

I'd have thought that the best place to measure the no feedback case was the Arctic, where there is no water vapour feedback and the place to measure the feedback case are the tropics which is where positive water vapour feedback, if it exists at all, should be seen.

There is the lack of evidence supporting positive water vapour feedback, suggesting that nature has a mechanism to limit the concentration of water vapour in the atmosphere.

Truth n ° 10 The water vapour content of the air has been roughly constant since more than 50 years but the humidity of the upper layers of the troposphere has been decreasing: the IPCC foretold the opposite to assert its «positive water vapour feedback» with increasing CO2.

The water vapour content of the air has been roughly constant since more than 50 years but the humidity of the upper layers of the troposphere has been decreasing: the IPCC foretold the opposite to assert its «positive water vapour feedback» with increasing CO2.

If water vapour feedback was positive then due to the increased evaporation spurred on by the original warming in the MWP there should have ensued a period of elevated temperatures for thousands of years until the cooling of the Holocene as we dip into the next glacial period overwhelmed the positive water vapour forcing.

Certainly sounds like a nice, physically plausible mechanism: — RRB - rather than say something like CO2 (which needs massively unrestrained & unstable positive water vapour feedback).

With regards to «climate modelling», an assumed (positive water vapour feedback) warming mechanism that can not be observed, that there is no experimental evidence for, combined with after the fact, admitted as invented cooling factors....

Feedbacks, Well the data to date does not have a significant positive water vapour feedback.

«Positive Water Vapour Feedback in Climate Models Confirmed by Satellite Data.»

Not exact matches

Extra carbon dioxide means a warmer world — and then positive feedback effects from things like water vapour and ice loss will make it warmer still

First that CO2 is the main climate driver, second that in calculating climate sensitivity the GHE due to water vapour should be added to that of CO2 as a feed back effect and third that the GHE of water vapour is always positive.As to the last point the feedbacks can not be positive otherwise we wouldn't be here to talk about it.

Remember that direct greenhouse effect from CO2 is quite small; the predictions rely on positive feedback from other effects (particularly water vapour feedbacks, a far more significant greenhouse gas) to cause substantial warming.

And that additional water vapour would in turn cause further warming - this being a positive feedback, in which carbon dioxide acts as a direct regulator of temperature, and is then joined in that role by more water vapour as temperatures increase.

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.

[blockquote] The water vapour positive feedback theory has already been comprehensively disproven by independent investigations by Douglass, Lindzen, Paltridge and Spencer, inter alia (who used satellite data and radiosondes to reach their conclusions and showed that the posited feedbacks are either missing or negative).

However, they can provide both positive and negative forcing» and Ray # 252 «we understand extremely well the way greenhouse gasses [sic] like CO2 warm the planet» So here we go — Assumptions from considerations of physics: Unless CO2 could enlist water vapour to amplify its forcing it would simply be an unremarkable trace gas in the atmosphere, but — CO2 + water (vapour) = + ve feedback implying warming CO2 + water (liquid) = - ve feedback implying cooling Facts: Clouds cover half the surface of the planet.

The water vapour theory suggests that a small increase in CO2 will result in a large positive feedback loop from water vapour and this feedback loop will lead to dangerous warming.

Positive feedback caused by rise in water vapour (caused by warming) accounts for perhaps half of the estimated warming and this will be located most where the air is humid in contradiction to Dyson's «cold and dry».

However both do in fact force global temperature, therefore both could be called forcings and the greenhouse effect of water vapour would then be a positive feedback forcing.

Observations of the humidity in the upper troposphere and its relation with sea surface temperature in areas of deep convection point to an overall positive climate feedback by water vapour in the upper troposphere, which is inconsistent with the Iris effect.

After all the positive feedbackfrom water vapour was in the theory from its inception and is now more secure than before.

Fig 2A shows that there are (small) positive SST anomalies during these ISOs and (clear) water vapour positive anomalies, at least at the peak of the warming phase of ISOs.

However, the greenhouse effect from water vapour is due to a (positive) feedback from the temperature and so any warming caused by CO2 is amplified by water vapour.

Then we're back to the plain wrong stuff again: it has already been pointed out above that 3 - 4 times positive feedback from water vapour is incorrect (it's roughly 2x).

[10] All of the models used by the IPCC assume that this increase in water vapour will result in a positive feedback in the order of 3 - 4 times the increase in temperature that would be caused by the increase in CO2 alone.

Water vapour is also the dominant positive feedback in our climate system and amplifies any warming caused by changes in atmospheric CO2.

Climate models suggest that water vapour and snow cover, at least, are «positive feedbacks» and so should enhance the warming.

Much of the warming feared by the alarmists relies upon a positive feedback involving increased water vapour exaggerating any CO2 warming effect.

However, the contributions of water vapour / lapse rate and surface albedo feedbacks to sensitivity spread are non-negligible, particularly since their impact is reinforced by the mean model cloud feedback being positive and quite strong.

Second, the feedbacks are all based on a series of assumptions that climate science will not question (water vapour, positive cloud feedback, no / tiny lapse rate change).

The fact that is being overlooked is that the main positive feedback effect is thought to be, «more water vapour gives more temperature which gives more water vapour».

Hence water vapour leads to a lower surface temperature, so there goes all that positive feedback the IPCC likes to tell you about.

However, you have avoided my last comment that without a positive feedback from water vapour there is no chance of runaway global warming arising from increasing atmospheric CO2 levels.

More water vapour means also more clouds, which in the models are used as positive feedback.

Of course Ferdinand is right not to project catastrophism onto anthropogenic CO2 levels for as you likely know there is a inverse logarithmic relationship between changes in temperature and CO2 levels such that without the assumed positive feedback from water vapour there is no chance of runaway global warming, tipping points or whatever.

I mean, surely increased water vapour from even 1.3 C temp rise (400ppm CO2) will cause a continuous positive feedback loop to fry us...

As I've demonstrated, some warming has to be attributed to the positive feedback effect of water vapour, however, you are right in saying that the trigger for past warming was (almost always) solar activity (or Milankovitch cycles).

He argues that the current computer models which make more alarming predictions are unreliable, and based on the assumption of large positive «water vapour feedbacks».

Nurse hasn't the foggiest idea about the key part of climate science, aerosols / water vapour interactions supposed to produce dangerous positive feedback.

For instance if a 1 degree increase in T leads to lets say a further 3 degree increase through positive feedback with water vapour then shouldn't this 3 degree increase lead to a further 9 degree increase and then a 27 degree increase etc..

I would like to gain a better understanding of water vapour and positive feedback.

And tudddaaaa using simple logic clouds become a positive feed back and for all those that do nt know, gaseous water vapour is where clouds come from but we have no idea how, when, where or why and neither do the models.

The fact that the actual measured planetary warming is less than the lowest IPCC model prediction warming and is found only at high latitudes (which is not predicted by the IPCC models) logically supports the assertion that the planet's response to a change in forcing is to resist the change (negative feedback, planetary clouds in the tropics increase reflecting more sunlight in to space) rather than to amplify the change (positive feedback) due increased water vapour in the atmosphere.

If water vapour feedback was positive they would never had ended.

Basically the tropical troposheric hotspot is evidence of positive feedback amplification from water vapour.

A slight change of ocean temperature (after a delay caused by the high specific heat of water, the annual mixing of thermocline waters with deeper waters in storms) ensures that rising CO2 reduces infrared absorbing H2O vapour while slightly increasing cloud cover (thus Earth's albedo), as evidenced by the fact that the NOAA data from 1948 - 2008 shows a fall in global humidity (not the positive feedback rise presumed by NASA's models!)

Basically, Dr Ferenc Miskolczi's life as a NASA climate research scientist was made hell because he discovered that the extra water vapour being evaporated is not having a positive - feedback (increasing the CO2 warming effect by absorbing more infrared from the sun), instead it is going into increased cloud cover, which reflects incoming sunlight back to space.

tt: Now it's water vapour, not CO2, which is causing the positive feedback.

Its just nonsense to say that water vapour must first cause a further warming to be considered a positive feedback.

Existing climate models with a positive feedback from H2O are plain wrong, since they don't allow the heated water vapour to rise, forming clouds that contribute to global dimming, offsetting CO2 effects on temperature.