Bob Martin writes:
in 125143 20091209 135918 "J. Clarke" wrote:
phorbin wrote:
In article , lcb11211
@swbell.dotnet says...
While forrests are being protected from being harvested and being
bought up. Al Gore is making a fortune on "cool the earth"
priojects. Once the global warming fad has cooled ;~) no pun
intended, we will once again be coolong off and those forrests will
once again be sold off and harvested for fire wood.



http://www.scientificamerican.com/ar...en-answers-to-
climate-contrarian-nonsense&page=6

or

http://tinyurl.com/yjhput9

Just the fact that it describes the contrarian view as "nonsense" tells us
that it's a propaganda piece not to be taken credibly.

So if I say the moon is made of green cheese ...

Then you'd be a fool, since we've been there and know that it is not.

On the other hand, the current hysteria around anthropgenic
climate change (of which there is little doubt that man changes
climate, at least locally; consider the Urban Heat Island effect,
for instance; or land-use changes (why don't tornadoes strike
big cities, as a rule?)) is based on some pretty iffy science.

First, the temperature record.

Historical temperatures are both direct and derived. We have direct
temperature measurements for various parts of of the world for up to
the last 150 years. The longest sequence of such measurements are
available in the United States and Europe.

Temperatures before 1850 or so (and up to 1960 in many cases) are
derived from various measurements believed to be related to temperature
in some way. These are called proxies and include the width of
tree rings (the trees are selected such that they are believed to be
growth limited by temperature, not precipitation or other external
factors; for example long-lived trees at the alpine tree-line. A
set of bristlecone pines in the White Mountains in central California
were used in several temperature reconstructions as representative of
global temperatures in the last millenium.

Other proxies include speleotherms in caves, boreholes and the deuterium
oxygen isotope ratios in various ice cores from the ice caps and greenland.

Tree rings have been pretty much discredited as a temperature proxy by
the National Academy of Sciences (DAGS: Wegman/NAS report). Yet they
were the primary constituent of the so-called "Hockey Stick" graph used
by advocates of catastrophic climate change due to man to indicate that
the world is heading for a catastrophy. In addition, the statistical
methods used to produce a temperature signal from the tree rings and
other proxies used in the hockey stick produce the same graph from
random data (red noise). See McIntyre/McKitrick.

As for the last 150 years of surface temperature data, it should be no
surprise that over that time period, the location at which temperature
is measured changes, the time of day of the measurement (and the number
of measurements per day) changed, and in many cases the sites themselves
while once rural, became urban. This requires that the data be manipulated
(or adjusted) to accomodate these differences. The algorithms used by
Dr. Hanson at GISS seem to underestimate past temperatures, and boot current
temperatures. Dr. Peilke Sr. has a peer-reviewed paper out illustrating
the problems with the current surface temperature record as well as pointing
out the uncertainties in both the data, as well as the algorithms used to
fill in missing data and derived a global average temperature.

The error bars, while not generally discussed along with the temperature
anomolies, dwarf the 20th century anomoly of about 1 degree C.

Of course, the land surface is a small fraction of the planets surface,
so other means are used to derive a temperature signal for the 7/8ths
of the planet covered by oceans. The main measurement used is the
Sea Surface Temperature (SST). SST temperatures are also available for
about the last 100 years in the main shipping routes. This data was
measured several times a day by ships captains and logged in ships logs.
This log data has been collected and massaged to attempt to derive a
historical temperature trend for the oceans surface. However, over the
century the methods used to measure the SST changed (from dropping a
bucket over the side and hauling it up, to measuring intake cooling water
for modern ocean liners). The depth at which the measurements changed
along with the method, the tools changed from mercury thermometers to
thermocouples. All of these changes require that the data be massaged
(i.e. adjusted). This increases the error bars on the measurements
here as well.

An addition source of late 20th century upticks in the surface temperature
record are due to the Urban Heat Island effect; which is the effect
of a large city on the temperatures within that city. There are
researchers on both sides of the issue of whether the UHI has a
significant effect or not on the temperature trends; Some who discount
UHI have compared the temperatures in old, large cities like London
and Paris and extrapolated that that also applies to cites that
have significantly increased in the 20th century (atlanta, LA, BA, etc).

There is also the so called 'microsite' biases. Several of the
US sites used for the surface temperature record have had installed,
in the last decade, air conditioners, asphalt parking lots and
generators in the direct vicinity of the temperature sensor (in
some cases, the exhaust from the AC unit is three feet from the
sensor and obviously biases the summertime temperatures higher).

Other measurements in the last thirty years or so have been made by a
series of satellites with different instruments designed to measure
the temperature of the air at various altitudes (again by measuring
some effect and deriving a temperature from that effect). Where
multiple satellites were in orbit simultaneously, the data can be
adjusted with the known bias of the various instruments, but in the
case where there is no overlap between the measurements by different
instruments on different satellites, the adjustment required to match
the data is more complicated. There are at least two sets of
satellite data being used today (UAH and RSS), each of which uses a
different algorithm to adjust the data to produce a temperature trend.
Again, the error bars are are relatively large.

There is also relatively little data from the southern hemisphere yet.

Then there is CO2, which is a trace gas. The direct doubling of the
concentration of CO2 in the atmosphere would result in perhaps a
degree C of heating. This is accepted. However, there is a school
of thought (of which Dr. Hanson is a prime proponent) which believes
that this doubling will lead to feedback effects from other greenhouse
gasses, particularly water vapor (which is the main greenhouse gas by
far). I.e. the belief is that adding CO2 will cause a cascading
increase in the water vapor component of the atmosphere leading to
catestrophic warming.

The only evidence for this is from computer models. Note that not one
of the dozen or so global climate models (GCM) correctly hindcast nor
forcast the actual weather. The models don't include clouds or
water vapor. Yet, the modellers claim that while no single model
is accurate, the models, when averaged together accurately predict
the future.

Given the above, I see no reason to rush through any massive economic
changes to adapt (assuming that a warming planet is a _bad_ thing, which
is another iffy proposition).

I'd point out the following, both peer reviewed climate scientists, who
present a more nuanced view of climate change:

Dr. Richard Lindzen, MIT
Dr. Roger Pielke, Sr., U of Colorado