The Mudcat Café TM
Thread #87391   Message #2679570
Posted By: Amos
13-Jul-09 - 08:44 PM
Thread Name: BS: Where's the Global Warming
Subject: RE: BS: Where's the Global Warming
Furthermore, the solar flare cycle has been uncommonly LOW for the last few years, if my information is correct.

The air temperature data is not a complete index, since it is much less absorbent than water bodies and land masses. Satellites do not measure temperature in air directly; they infer it from measuring radiances in various wavelength bands, which must then be mathematically inverted to obtain indirect inferences of temperature. "The resulting temperature profiles depend on details of the methods that are used to obtain temperatures from radiances. As a result, different groups that have analyzed the satellite data to calculate temperature trends have obtained a range of values. Among these groups are Remote Sensing Systems (RSS) and the University of Alabama in Huntsville (UAH).
To compare to the increase from the surface record (of approximately +0.07 °C/decade over the past century and +0.17 °C/decade since 1979) it is more appropriate to derive trends for the lower troposphere in which the stratospheric cooling is removed. Doing this, through June 2009:
RSS v3.1 finds a trend of +0.152 °C/decade.[3]
UAH analysis finds +0.12°C/decade.[4]
An alternative adjustment introduced by Fu et al. (2004)[5] finds trends (1979-2001) of +0.19 °C/decade when applied to the RSS data set.[6] A less regularly updated analysis is that of Vinnikov and Grody with +0.20°C per decade (1978–2004).[7], although it must be noted that RSS also has a higher trend when taken only to 2004 (+0.186 °C/decade)
In 1996, Hurrell and Trenberth published in the Journal of Climate an analysis showing a warming trend of +0.18 °C/decade from 1979-1995.[8]
Using the T2 channel (which include significant contributions from the stratosphere, which has cooled), Mears et al. of Remote Sensing Systems (RSS) find (through March 2008) a trend of +0.110 °C/decade.[3] Spencer and Christy of the University of Alabama in Huntsville (UAH), find a smaller trend of +0.050 °C/decade.[9]"

(Source article here

"the warming trend in global-mean surface temperature observations during the past 20 years is undoubtedly real and is substantially greater than the average rate of warming during the twentieth century. The disparity between surface and upper air trends in no way invalidates the conclusion that surface temperature has been rising."[21][22]

Board on Atmospheric Sciences and Climate (2000). "Executive Summary". Reconciling Observations of Global Temperature Change. Washington, D.C.: National Academy Press. pp. 1–4. ISBN 0309068916.
^ Llanos, Miguel (2000-01-13). "Panel weighs in on global warming: Earth's surface is warmer, they say, even if upper air isn't". MSNBC.

"he following figure shows a calculation of straight temperature averages for all of the reporting stations for 1950 to 2000 [http://www.uoguelph.ca/~rmckitri/research/nvst.html]. While a straight average is not meaningful for global temperature calculation (since areas with more stations would have higher weighting), it illustrates that the disappearance of so many stations may have introduced an upward temperature bias. As can be seen in the figure, the straight average of all global stations does not fluctuate much until 1990, at which point the average temperature jumps up. This observational bias can influence the calculation of area-weighted averages to some extent. A study by Willmott, Robeson and Feddema ("Influence of Spatially Variable Instrument Networks on Climatic Averages, Geophysical Research Letters vol 18 No. 12, pp2249-2251, Dec 1991) calculated a +0.2C bias in the global average due to pre-1990 station closures.


See graphs at http://www.appinsys.com/GlobalWarming/GW_Part2_GlobalTempMeasure.htm.

This is not to say that a lot of the data cannot be argued. But the blunt denial of surface warming trends, melting icecaps, liquefying permafrost, and other plain evidence is really thick. The right answer is to try and get better quantifying values and clearer analysis, rather than railling and denying.


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