Physical, mathematical and observational grounds are employed to show that there is no physically meaningful global temperature for the Earth in the context of the issue of global warming. While it is always possible to construct statistics for any given set of local temperature data, an inﬁnite range of such statistics is mathematically permissible if physical principles provide no explicit basis for choosing among them. Distinct and equally valid statistical rules can and do show opposite trends when applied to the results of computations from physical models and real data in the atmosphere. A given temperature ﬁeld can be interpreted as both “warming” and “cooling” simultaneously, making the concept of warming in the context of the issue of global warming physically ill-posed.
Thermodynamic variables come in two varieties: extensive and intensive. Extensive variables are proportional to the size of the system. They are additive. In this category we ﬁnd volume, mass, energy, entropy, particle number etc. We can combine two systems and the values of extensive variables for the whole system will simply be the sum of the values from the two components. Correspondingly a mean subsystem (loosely called the average) will have this sum divided by the number of components. Such an average over a quantity like mass is meaningful because the sum is meaningful. For example average mass is of importance to airlines because it is helpful to estimate the total load of an aircraft without having to weigh every passenger.
Intensive variables, by contrast, are independent of system size and represent a quality of the system: temperature, pressure, chemical potential etc. In this case combining two systems will not yield an overall intensive quantity equal to the sum of its components. For example two identical subsystems do not have a total temperature or pressure twice those of its components. A sum over intensive variables carries no physical meaning. Dividing meaningless totals by the number of components cannot reverse this outcome. In special circumstances averaging might approximate the equilibrium temperature after mixing, but this is irrelevant to the analysis of an out-of-equilibrium case like the Earth’s climate.
|Figure 1 Mean Northern Hemisphere Temperature change|
from weather station records, as derived in 1975, (from Stanley 3)
|Figure 2. Global Temperatures over |
different periods (IPCC !9944)
|Figure 3 Global Temperatures 2500 BC to 2040 AD5 Note that they have avoided mentioning any specific temperature value|
|Figure 4 Current Hadley CRUT MGSTAR6|
|Figure 5 Comparisons between all the proxy temperature anomaly records7|
|Figure 6 RSS MSU Temperature anomalies 8|