Oral Presentation Royal Australian Chemical Institute National Congress 2026

New tools from chemical thermodynamics for modelling climate change: How reversing heat and work in the Carnot Cycle may control the heat capacity of the troposphere and climate sensitivity of greenhouse gases. (136275)

Ivan R Kennedy 1 , Angus N Crossan 1 , Migdat Hodzic 2
  1. School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
  2. International University of Sarajevo, Sarajevo, Bosnia and Herzogovina

The Trenberth energy flux diagram of the radiative-convective model for global climate change shows incoming solar radiation (ISR) being dissipated as longer wavelength black body radiation emitted from the global surface, then from the top of the atmosphere (OLR). These energy fluxes may be recycled as heat by greenhouse gases like water and CO2 before eventual longwave emission to space. Increasing levels of greenhouse gases like CO2 and thus water force rises in tropospheric temperature, a function of global surface heat capacity. This model is linked to the meteorology of the atmosphere to determine effects on climate and extreme weather. Climate modelling has only a minor role for chemical thermodynamics and even less for quantum theory. To rectify this, we have introduced action mechanics, allowing several new developments.

  • A new method to calculate entropy (S) and absolute Gibbs energy (G) of all atmospheric gases as a logarithmic function of their molecular quantum states [1].
  • Inclusion of vortical entropy states for tropospheric gases in the molecular flows of anticyclones and cyclones, important in maintaining wind power. These states are also logarithmic functions of orbital quantum action states [2]. 
  • A non-adiabatic method to calculate the lapse rates in temperature with changing altitude, using the virial theorems of Lagrange and Clausius [3] providing further work potential from gravity.

The Carnot cycle estimates maximum efficiency of heat engines [1], where absorption of radiative heat with no cyclic change in temperature of  a working fluid requires an efficient transition to work. Reversible transfers of heat to vortical or gravitational work followed by turbulent heat release is predicted to control rises in temperature, if greenhouse gases increase. Predicted variations in heat capacity may require the need for climate management of extreme weather. Some means of testing this new thermodynamic hypothesis from its predictions will be discussed.

  1. Kennedy, I.R.; Hodzic, M. Action and entropy in heat engines: An action revision of the Carnot Cycle. Entropy 2021, 23, 860. https://doi.org/10.3390/e23070860.
  2. Kennedy, I.R.; Hodzic, M. Applying the action principle classical mechanics to the thermodynamics of the troposphere. 2023, .Appl. Mech. 4, 729-751. https://doi.org/10.3390/applmech4020037
  3. Kennedy, Ivan R., Hodzic, Migdat & Crossan, A.N. (2025) Gibbs quantum fields computed by action mechanics recycle emissions absorbed by greenhouse gases, optimising the elevation of the troposphere and surface temperature using the Virial theorem. Thermo 5, 25. https://doi.org/10.3390/thermo5030025.