In this post I'm going to risk a 15 yard penalty for piling on and point out that the IPCC's AR4 Technical Summary claim that the Earth's water vapor is increasing is false.
First, the claim. It comes from the IPCC's AR4 Technical Summary.
TS.3.1.3 Changes in the Water Cycle: Water Vapour, Clouds, Precipitation and Tropical Storms
Tropospheric water vapour is increasing (Figure TS.8). Surface specific humidity has generally increased since 1976 in close association with higher temperatures over both land and ocean. Total column water vapour has increased over the global oceans by 1.2 ± 0.3% per decade (95% confidence limits) from 1988 to 2004. The observed regional changes are consistent in pattern and amount with the changes in SST and the assumption of a near-constant relative humidity increase in water vapour mixing ratio. The additional atmospheric water vapour implies increased moisture availability for precipitation.
The claim is that both tropospheric and surface water vapor is increasing from 1988 to 2004. Here's a screen grab of the accompanying graph:
The top part of the graph shows the alleged increase in water vapor. The bottom part of the graph shows the increase in temperatures. The meaning is pretty clear, increased water vapor is causing the temperatures to go up.
The problem is, the amount of water vapor in the troposphere, or anywhere else, hasn't increased between 1988 to 2004 or at any time since 1983. Atmospheric water vapor is measured by NASA's ISCCP project, and the results of their measurements from June, 1983 to July, 2008 are shown in the Climate4You graph below:
Tropospheric water vapor is the middle green line and it's been holding fairly steady for the entire graph. In fact, it's actually slightly lower at the end of the graph than at the beginning, as are all the other water vapor measurements in that graph.
Once again, the IPCC is presenting bogus claims.
Water Vapor And Cosmic Rays
A relationship that does hold up is that between cosmic rays and clouds and water vapor. As cosmic rays increase or decrease, so too do clouds and water vapor. You can see the relationship between cosmic rays (brown), clouds (light blue) and water vapor (dark blue) in the graph below:
The changes in cosmic rays along with a 1 year cycle that represents the Earth revolving around the sun provide a very good correlation with changes in clouds and water vapor. The data in the graph originally comes from NASA's ISCCP and the Climax cosmic ray monitoring system. You can also get the data for the above graph from the Climate Scientist Starter Kit Spreadsheet.
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And now for Amazongate
IPCC's AR4 Technical Summary.
ISCCP Cloud Data
Climax Cosmic Ray Data
Climate Scientist Starter Kit Spreadsheet.