Prior posts on negative feedback from water vapor
H2O decreasing while CO2 rises !
Dire predictions of global warming all rely on positive feedback from water vapor. The argument goes that as surface temperatures rise so more water will evaporate from the oceans thereby amplifying temperatures because H2O itself is a strong greenhouse gas. Climate models all assume net amplification factors of between 1.5 and 6. Has the water content of the atmosphere actually been increasing as predicted?
NASA have just released their latest NVAP-M survey of global water content derived from satellite data and radio-sondes over the period from 1988 to 2009. This new data is explicitly intended for climate studies . So lets take a look at the comparison between actual NVAP-M atmospheric H2O levels and those of CO2 as measured at Mauna Loa. I have extracted all the daily measurement NVAP-M data and then calculated the global average. Figure 1 shows the running 30 day average of all the daily data recorde between 1988 and 2009 inclusive. The 365 day (yearly) running average is also shown. Plotted on the right hand scale are the Mauna Loa CO2 concentration data in red over the same period.
Fig1: Total precipitative H2O (running 30 day average) compared to Mauna Loa CO2 data in red. The central black curve is a running 365 day average.
There is indeed some correlation in the data from 1988 until 1998, but thereafter the two trends diverge dramatically. Total atmospheric water content actually falls despite a relentless slow rise in CO2. This fall in atmospheric H2O also coincides with the observed stalling of global temperatures for the last 16 years. All climate models (that I am aware of} predict exactly the opposite. Something is clearly amiss with theory. Is it not now time for “consensus” scientists to have a rethink?
Thanks to Ken Gregory for providing me the data. The conversion from NetCDF was a bit of a nightmare!
NASA NVAP-M data is available here. Thanks to NASA Water Vapor Project-Measures (NVAP-M) team.
"In fact, the basic physics of the CO2 molecule makes it hard to justify a number much larger than ∆T2 = 1 C – with no feedbacks. The number 3 C comes from various positive feedback mechanisms from water vapor and clouds that were invented to make the eﬀects of more CO2 look more frightening. But observations suggest that the feedbacks are small and may even be negative."
see also full paper at
But surely less H20 = less clouds = more irradiance = global warming!ReplyDelete
Oh! Sorry. We don't consider clouds...
Neither do we consider radiative feedback from heat which leaves the Earth's surface through conduction, convection and latent heat of evaporation of water. If this equals 2X then X radiates away from the planet and X back towards the planet thus warming it.
Ooops sorry. I was forgetting all those pesky GHGs which absorb and re-emit this red-wards shifted back radiation back out to space. Double back radiation.
Yeah, and don't forget the triple back radiation, and quadruple back radiation, and the perpetual motion machine.Delete
A cooler object (atmosphere) cannot make a warmer object (ground) warmer still. No matter how much radiation. DOLT!
This is exactly what Dr. Ferenc M. Miskolczi predicted. The climate models take no account of the minimum energy principal and hense are plain straight wrong.ReplyDelete
Does not the sharp drop off in water vapor ca. 2010 suggest there is something wrong with the satellite?ReplyDelete
Even Kevin Trenberth has published that large spikes in water vapor were driven by El Nino. The decline in water vapor coincides with the swtich to a negative Pacific Decadal Oscillation and fewer El Nino. Trenberth's "wetter and warmer" world is driven by El Nino and the PDO not CO2.ReplyDelete
I believe Ken Gregory of Calgary emailed several scientists about a similar observation on August 31, 2008. I forwarded his email to Richard Lindzen at that time.ReplyDelete
See the graph entitled “Global Relative Humidity 300-700mb” under the heading “Water Vapour Feedback” about halfway down the long article “Climate Change Science”.
Thanks, yes there are other datasets also showing a declining trend in water vapor.Delete
That page is packed with a wealth of useful information!
The wv does seem to correlate with warming though. It increases up until temps level off.ReplyDelete
i'm not expert, but how can I compare this data (NASA vapor decreasing) with this other study, in which vapor trend seems contanty increasing?ReplyDelete
they seem different data (precipitable vapor one, and coloumn vapor the other)??? can you suggest how to correctly read theese data?
1. Your paper tries to remove the seasonal component, NASA NVAP doesn't [as far as I know]Delete
2. Your paper says in the conclusion that there is no statistically significant trend when the 1998 El Nino is taken into account.
3. NVAP data is from multiple data sets, satellite and radiosonde, therefore probably more accurate.
4. Your paper covers a shorter time period
no trend found evaporation