From Quantum Mechanics to Climate Change: Global Warming From First Principles

Although the scientific principles of anthropogenic climate change are now extremely well-established, all existing descriptions of the physics of global warming are either partly empirical or rely on the results of complex numerical models. Here, we present a description of radiative forcing and climate sensitivity that begins from the basic quantum properties of the CO₂ molecule. The shape of the CO₂ 15 micron band, which is so critical to the strength of CO₂ radiative forcing, can be understood in terms of vibrational-rotational states and a quantum resonance effect (Fermi resonance). We discuss how classical analogy to the coupled pendulum experiment can be used to understand the nature of this phenomenon in simple terms. We finish by deriving a new analytic equation for CO₂ radiative forcing expressed in terms of basic molecular properties such as bond strength and atomic mass. Our aim is for this analysis to elucidate the fundamental physics of climate change for both climate scientists and for physicists working in other fields.