I have relocated this text here while I'm restructing the profile - its easier to start with a clean slate. Then I'll reinstate the section on climate change and rewrite it to make it less of a puff piece. --Bob Burton 04:09, 3 May 2005 (EDT)
McKitrick and climate change
is an economist who suggests that the concept of global temperature has no physical meaning. However, criticism of his work has shown an ignorance of basic science by his detractors which, when examined, invalidates their claims.
For an example of the types of poor scientific understanding shown by a particular critic with a poor understanding of statistics and thermodynamical theory see the following links:
Tim Lambert has claimed that McKitrick has [http://cgi.cse.unsw.edu.au/~lambert/cgi-bin/blog/2004/04#mckitrick "messed up an analysis of the number of weather stations"], [http://cgi.cse.unsw.edu.au/~lambert/cgi-bin/blog/2004/04#mckitrick2 "showed he knew almost nothing about climate"], [http://cgi.cse.unsw.edu.au/~lambert/cgi-bin/blog/2004/05#georgia "flunked basic thermodynamics"], [http://cgi.cse.unsw.edu.au/~lambert/cgi-bin/blog/2004/05#mckitrick3 "couldn’t handle missing values correctly"] and "invented his own temperature scale".
McKitrick is a co-author of Taken By Storm, a book which has been supposed to have serious scientific errors which invalidate its major claims, usually made by non-scientists.
Decrease in stations
McKitrick has suggested that one source of change in the commonly-used global averages of temperature data is the decrease in the number of stations measuring the temperature.
Unfortunately, the claim is usually (deliberately?) mangled to say that which is not claimed. The book "Taken by Storm" makes the point that every time a station closes it produces a movement in the calculated average (page 140), but most of the warming trends have been predominantly in the urban or semi-urban stations with the rural stations showing little or no warming in the last 70 years. So if rural stations are closed (and many were subsequently to 1990 with the fall of the Soviet Union), then the change to the average is to produce a non-climatic warming, which is what has happened. The difference between the surface record and the independently checked and calibrated satellite record became even wider after 1990 - a sure sign that the apparent warming was due in part to the closure of mainly rural stations which showed much lower warming (if any) compared to the urbanized stations left behind. (Update: Of course, regardless of how accurate, relevant, and complete other claims presented here are, the difference between the satellite and surface records was accounted for in 2004. In addition, there's plenty of other observational evidence of an overall warming trend, apparently beyond anything explainable by natural events.)
This claim is easy to verify: simply look only at the stations that have been measuring each year. McKitrick did this, but Tim Lambert confused what was said and claimed that McKitrick's claim was wrong -- "the global warming continues to exist even when limited to these stations". But Lambert made a clear mistake in his reasoning in insisting that the since the warming could be seen after 1990 then McKitrick must be wrong - a clear category mistake.
When confronted, McKitrick responded by claiming that to calculate global temperature, a random sample of stations across the Earth was required. This is true, as this is standard procedure in statistical analysis.
Tim Lamber continues to plow his lonely furrow of making claims about McKitrick and Essex's book, producing his own "audit" of what he thinks McKitrick said.
In the "Corrections to the McKitrick..", Lambert betrays his fundamental misunderstanding of what thermodynamic states are. He quotes McKitrick:
“The main problem in the debate over what the Global Temperature is doing is that there is no such thing as a Global Temperature. Temperature is a continuous field, not a scalar, and there is no physics to guide reducing this field to a scalar, by averaging or any other method. Consequently the common practice of climate measurement is an ad hoc approximation of a non-existent quantity.”
and then compounds his misunderstanding, by responding:
"This is untrue. Average temperature has a real, physical meaning. For example, if I have one kg of water at 20 degrees and another at 30 degrees, then their average temperature is 25 degrees. This is the temperature I would get if I mixed the water."
But Tim would only get 25 degrees if both masses of water are in THERMODYNAMIC EQUILIBRIUM and the water was left to settle into another thermodynamic equilibrium (and there's no energy loss, while this is happening!). In that case the temperature field of the water masses (an infinitely fine vector quantity) can be reduced to a scalar quantity, and can be averaged in the way described. "Average temperature" as Tim Lambert should know, only has physical meaning if the system or systems are in thermodynamic equilibrium.
The other thing to note about the water example is that there is no way to say if the system (ie the 2 liquids) is "warming" or "cooling" as it moves to its mixing equilibrium, because there is no one temperature, and the average can go up or down depending on how you average them. Lambert never mentions that point, which of course is more pertinent to the global warming topic.
Since the atmosphere is demonstrably not in thermodynamic equilibrium (or there'd be no weather, let alone climate change to worry about), then all bets are off as to what an arithmetic mean of a temperature FIELD means. As McKitrick and Essex rightly point out, there is no physical theory that says how to derive a single number representing "global mean temperature" for a temperature field, which is not in thermodynamic equilibrium, by some mathematical operation such as a simple arithmetic mean.