“Human Influences on the climate are small (1%) perturbation to natural energy flows”
WILLIAM HAPPER
If the stories, from the media, politicians and activists, about the potential catastrophic consequences of greenhouse gases (GHGs) have any foundations, these must lie in the physics of the atmosphere.
One does not have to delve far into this to realise that the popular notion that there is a simple relationship between the amounts of CO2 (carbon dioxide) and other trace gases such as N2O (nitrous oxide) and CH4 (methane) in the atmosphere and the global surface temperature is misleading.
The surface temperature of the Earth is determined by the interplay between heating due to radiation from the sun and cooling by infrared radiation (IR) out to space.
Even on a first cut analysis, the mechanisms are complicated and involve many areas of physics. These include, inter alia, the Laws of Thermodynamics, the Gas Laws and gravity, (which determine convection and adiabatic temperature gradients in a planetary atmosphere), and the quantum mechanical absorption and emission of radiation (which differs according to frequency) by the different gases and liquid (cloud) surfaces in the atmosphere.
One prominent atmospheric physicist who has sought to bring clarity to this subject is Will Happer, Emeritus Professor of Physics at Princeton.
In 2011, Happer authored a briefing paper for the GWPF, “The Truth About Greenhouse Gasses”. In 2018, along with MIT Professor Richard Lindzen and physicist Steven Koonin, he co-authored a comprehensive and very informative Tutorial on Climate Science for US Federal Judge William Alsup.
He has given many lectures aimed at lay audiences for example in 2021 at a Clintel conference in Amsterdam and at a Heartland Institute conference, which summarise the key physics and issues.
Happer’s recent technical papers, with co-author Wijngaarden, include:-
Some key conclusions from Happer’s work:
• the great majority (over 90%) of the greenhouse effect is accounted for by water vapour and clouds,
• the effect of CO2 is largely saturated at its present concentration (about 420 ppm), with an estimated climate sensitivity (ECS) of only around 1-2 C* of surface warming per doubling of CO2, (assuming clear skies),
• the impact of the trace gases CH4 and N2O is minimal, with an ECS 3-4 times lower than CO2, due to the combination of their low concentrations and the prior saturation of their IR absorbtion/emission spectra by water vapour.
(*) this range depends on whether atmospheric humidity remains constant in absolute or in relative terms as temperature increases
Happer’s atmospheric physics is corroborated by the good fit of the calculated radiation spectra with observed satellite measurements of IR radiation, taken in clear skies, over different climatic regions of the Earth, as evidenced in his technical papers.
This situation is unlike that of Global Climate Models (GCMs), which typically incorporate excessive ECS sensitivities to GHGs, generate projections that exceed observed warming trends by a factor of 2-3 times or more, and have a poor fit with observed climatic variations.
An important point is that Happer’s radiative transfer analysis is based on clear skies. The presence of clouds, which are essentially opaque across the IR spectrum, considerably dilutes the effect of GHGs. Happer’s estimates therefore provide an upper bound on the extent of the plausible effect of changes in GHG concentrations.
Happer’s papers are not contradicted by the scientific papers underlying IPCC reports. Moreover, they serve to demarcate the dividing line between the underlying thermodynamics and radiation physics, which imply only modest warming from GHGs, and over-ambitious GCM simulations, whose ad-hoc positive feedback assumptions generate amplified warming and form the basis of the IPCC’s climate alarmism.
Needless to say, such elucidation by Happer does not sit comfortably with the alarmist narrative and mindset prevailing in the media and in political and activist circles. As a result, notwithstanding the compelling observational evidence, Wijngaarden & Happer’s work suffers from censorship and their papers languish as pre-prints on the physics community arXiv server, with no journal bold enough to publish them.
“Our understanding of climate and climate change is fraught with uncertainties but the best available evidence does not indicate catastrophe is in the offing.”
William Happer
Happer’s work is recommended reading and viewing.
(PhD, Theoretical Physics)
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