Global Mean Surface Temperature (GMST) Is Meaningless

That Guy
2 hours ago
2 min read

An article by J. Cohler titled “The Father of Lies Hijacking Climate Science: Global Mean Surface Temperature Does Not Exist” was published in the Winter 2025 issue of Journal of American Physicians and Surgeons (Volume 30 Number 4).

The article is about 5 pages, including the references. As the title states, it discusses the flaws of the “global mean surface temperature” (GMST) that was used to set the target of the Paris Agreement.

The UN Intergovernmental Panel on Climate Change (IPCC) has assessed the risks of global warming at 1.5°C or 2°C above pre-industrial levels as critical thresholds that some have characterized as the most important numbers in the world. According to the IPCC assessments, global mean surface temperature (GMST) must not increase more than these amounts above the pre-industrial baseline (1850–1900) to prevent irreversible catastrophes from global warming.

This article is in part based on the paper “Does a Global Temperature Exist?” by Christopher Essex, Ross McKitrick and Bjarne Andresen, which concludes: “There is no global temperature.” This was first published in 2007 and “remained unchallenged for more than 18 years—highly unusual in modern science when dealing with highly controversial topics”.

So, Cohler’s paper is not exactly news but it is a worthy reminder and is easily accessible.

Cohler first mentions that temperature is an intensive thermodynamic property. Mass, for example, is an extensive property and when multiple systems are combined, their respective masses can be added to get the total. One cannot do that for temperature, nor can it be averaged in a way that is meaningful. There are also many ways to calculate this average, yielding very different figures.

A more fundamental point is that temperature is a state property in equilibrium systems.

1/T = (∂S/∂U) at constant V and N

where S is entropy, U is internal energy, V is volume and N is the number of particles.

The term “warming”, however, implies heat (energy) transfer. There is obviously a relationship between energy and temperature, but averaging and manipulating temperatures across a large, non-equilibrium system such as the Earth does not reveal any meaningful regarding heat transfer.

Perhaps most tellingly, the International Standards Organization (ISO), tasked in 2002 with defining global temperature, never completed this assignment. ISO, which routinely defines complex technical standards across all fields of engineering and science, has to this day declined to define global surface temperature. This omission by the world’s premier standards body strongly suggests recognition that no scientifically valid definition exists.

In short, GMST is an “arbitrary statistical construct”. Amongst other things, the author concludes:

We must name this clearly: it is not merely mathematical error but systematic scientific fraud perpetrated by institutions that have forsaken physical truth for political utility. … The path forward is clear: return to physically meaningful metrics grounded in thermodynamics. Energy budgets—measured in joules or watt-seconds—are the proper foundation for understanding Earth’s thermal behavior. Statistical temperature trends, no matter how mathematically sophisticated, can never substitute for thermodynamic reality.

Be sure to subscribe to our mailing list so you get each new Opinyun that comes out!