Sentences with phrase «strong water vapor feedback»

The point is quite simply: The IPCC assumption of essentially constant relative with warming is not supported by the physically observed data, therefore the assumption of strong water vapor feedback with warming is also not supported by the observations.

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.

Anthropogenic greenhouse forcing and strong water vapor feedback increase temperature in Europe.

Finally, because of the posited strong water vapor feedback, which depends on absolute, not anomaly, temperatures, one would expect that the relationship should be positive, not negative due to the greater rate of accumulation of water vapor at higher absolute temperatures.

Specific humidity content of the air has increased, as expected as part of the conventional water vapor feedback, but in fact relative humidity also increased between 1950 and 1990, indicating a stronger water vapor feedback than given by the conventional assumption of fixed relative humidity.

Not exact matches

So the fact that we have this very strong drying in the tropics during glaciation would argue for a strong feedback of water vapor concentration to the global climate during glacial - interglacial cycles.»

The factors that determine this asymmetry are various, involving ice albedo feedbacks, cloud feedbacks and other atmospheric processes, e.g., water vapor content increases approximately exponentially with temperature (Clausius - Clapeyron equation) so that the water vapor feedback gets stronger the warmer it is.

This isn't news to top climate scientists around the world (see Hadley Center: «Catastrophic» 5 — 7 °C warming by 2100 on current emissions path) or even to top climate scientists in this country (see US Geological Survey stunner: Sea - level rise in 2100 will likely «substantially exceed» IPCC projections, SW faces «permanent drying») and certainly not to people who follow the scientific literature, like Climate Progress readers (see Study: Water - vapor feedback is «strong and positive,» so we face «warming of several degrees Celsius»).

Water vapor is the largest and strongest feedback to CO2.

The important point here is that a small external forcing (orbital for ice - ages, or GHG plus aerosols & land use changes in the modern context) can be strongly amplified by the positive feedback mechanism (the strongest and quickest is atmospheric water vapor - a strong GHG, and has already been observed to increase.

This seems to imply the water vapor feedback gets stronger at higher temperatures so that the climate sensitivity does not decrease.

The water vapor and lapse rate feedbacks are typically combined because models show a strong negative correlation between the two.

We have no reason to be much concerned about CO2, unless there is a strong positive water vapor feedback.

It appears to me that the new «scientific evidence» is suggesting that water vapor feedback is not as strong as had been estimated by the models previously and that net cloud feedback may be neutral to slightly negative, rather than strongly positive, as predicted previously by the models.

manacker December 19, 2012 at 8:00 pm said:» It appears to me that the new «scientific evidence» is suggesting that water vapor feedback is not as strong as had been estimated by the models previously and that net cloud feedback may be neutral to slightly negative, rather than strongly positive, as predicted previously by the models»

Quoting Dr Roy Spencer: «One of the most robust feedback relationships across the IPCC climate models is that those models with the strongest positive water vapor feedback have the strongest negative lapse rate feedback (which is what the «hot spot» would represent).

When that is done, the evidence for substantial positive feedback from water vapor minus lapse rate, and snow / ice becomes almost inescapable, and the evidence from clouds suggests a positive feedback and excludes a strong negative feedback (long term — see below).

(While the data did suggest strong positive water vapor feedback, which enhances warming, that was far exceeded by the cooling effect of negative feedback from cloud changes.)»

Without a strong positive feedback from water vapor (as assumed in the models), Human - made climate forcing becomes insignificant.

On the other hand the projected positive feedbacks you support, which are COMPLETELY theoretical, depend on the LEAST understood aspects of the affect of water vapor and cloud formation, so the strong feedbacks PROJECTED are the least dependable, while the «OBSERVATIONS» used by Lindzen, Spencer, and others, support the lower estimates of climate sensitivity.

According to environmental scientist Dana Nuccitelli, the «literature consistently shows» that water vapor has a strong positive feedback and amplifies warming.

The only way to get scary warming projections from carbon dioxide (more than 1 °C / doubling) is by supposing a strong positive water vapor feedback, which is not supported by observations.

The strong positive water vapor feedback necessary for high sensitivity is also not happening.

Elliott et al. conclude, based on the selected data below 500 hPa only that SH (moisture content) increased slightly with warming, but not at a rate sufficiently strong to maintain constant RH, as is assumed by the IPCC models in estimating water vapor feedback.

The existence of a strong and positive water - vapor feedback means that projected business - as - usual greenhouse gas emissions over the next century are virtually guaranteed to produce warming of several degrees Celsius.

Interestingly, it seems that just about everybody now agrees water vapor provides a robustly strong and positive feedback

It's apparent that the negative feedbacks from water in all its phases are much stronger than the positive feedback from water vapor as a GHG.