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21-02-2003, 04:21 PM

In article ,
says...

On Thu, 20 Feb 2003 22:18:55 +0000, Daniel B. Wheeler wrote:

"Titan Point" wrote in message
...
On Wed, 19 Feb 2003 10:31:25 +0000, Daniel B. Wheeler wrote:

[snip]
The debate is not about global warming but about anthropogenic global
warming.
According to Warren Washington, that is not the debate. You are welcome
to disagree, of course. But the increased temperature globally within
the last 30 years strongly points to some particular effect which has
taken place or has accumulated within that time frame.

Funnily, satellite records calibrated with randio-sonde measurements have
found practically no increase in lower atmospheric temperature since 1979.
The increase of the last 30 years is nearly lost in the statistical noise.
By no means is the range of temperature rise over the last century,
unusual or unprecedented.

Funny, that's incorrect.

S & C did not "calibrate" their analysis against the sonde data. They took
some sonde data, ran it thru a simulation to create a synthetic MSU signal
and ran that thru their algorithm. It's another simulation, which those
who don't like simulations should find disgusting.

There are now three sets of results from the MSU data, 2 of which produce
a warming trend similar to that seen in the surface record. The third by
Spencer and Christy (to which you presumably refer) now also indicates a
warming trend. You have consistently ignored the other two.

BTW, the MSU does not measure "temperature". It measures microwave intensity.

So whatever Washington thinks about the record of climate change in the
last 30 years appears to be entirely removed from what was actually
recorded.

You ignore the effects of the Great Salinity anomalie, which may have contributed
to the colder conditions of the late 1960's and 1970's.

The climate has warmed about 0.6C since 1900. There is no dispute about
this from anyone. The question is whether the increase in carbon
dioxide - over and above that which would be expected to be produced by
a warming climate - is significant to force the climate warmer in a
significant AND biologically negative way.
The temperature has increased nearly a full degree Fahrenheit since
accurate temperatures have been kept, about 1970 I believe. While I
don't know about your figure of .6C since 1900, the increase of 1 degree
F. since 1970 is, I believe, well documented. And that figure was
assessed in 1990, after only 20 years of data. CO2 concentrations were
likewise also observed to increase.

The satellite record shows a decadal increase of (Spencer and Cristy)
0.075C/decade or 0.225C over the last 30 years. It is also misleading to
begin your measurements in a known cold period and then act surprised when
you show a warming trend. That is called end-date distortion.

Funny, your own words refute your claim above of practically no warming.

For one who wants us to believe that natural variability is the cause of
all the changes in climate, you must also consider the fact that the MSU
record begins near the peak of a sunspot cycle. Thus, if the solar
variability does have an impact, it should also be seen in the satellite
record. Start-date distortion is just as much a problem as end-date
distortion.

Also, S & C's claims of little change in temperature were based upon results
calculated up to 1997 and have since been changed as the result of the
discovery of several errors in the analysis, such as corrections for orbital
decay and shift in time of day of Equitorial crossing.

According to measurements taken over the last century from properly
maintained, rural temperature stations, the warmest decade of the 20th
Century was the 1930s (for example 1934 saw fully one half of the
contiguous US in extreme drought, the "Dustbowl" years)

Your use of data for the U.S. ignores the fact that the "Dust Bowl" was in large
part the result of cropping practices in the dry lands of the Great Plains.
When drought hit, these poor soil conservation practices exacerbated the problems.
Farms were abandoned and the bare soil without plant cover is much hotter than
the same area would have been with plants/crops.

The very faint rise since 1970 is neither unprecendented nor surprising.

The rise in carbon dioxide during the 20th Century appears to be a
confounding factor rather than cause of 20th Century warmth.

Most of the increase in atmospheric CO2 happened after WW II.
The time lags in the result make detecting the anthropogenic warming very
difficult. Only during the last decade or so has the magnitude of the AGW
approached and possibly exceeded the range of natural variability.

--
Eric Swanson --- E-mail address: :-)
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