Climate Change 2021: The Physical Science Basis. Working Group I Contribution to the Sixth Assessment Report of IPCC. Chapter 7: The Earth's Energy Budget — An Update

"Climate Change 2021: The Physical Science Basis" (IPCC Working Group I Contribution to the Sixth Assessment Report) has been published by Cambridge University Press. The Report is dedicated to the memory of Sir John Houghton, whose textbook: "The Physics of Atmospheres" was published by the same company (1977, 1986, 2002). Unfortunately, the very essence of his book: the physics of atmospheric radiation transfer is missing from the entire Report (and from all its predecessors, including the Charney Report, 1979 and the Villach Statement, 1980). The fundamental relationships are based on the original two-stream equations of Karl Schwarzschild (1906, Eq. 11), whose name does not occur in the "Milestones in scientific understanding" (Fig. 1.6), not listed in the References, and his equations do not appear in the Report. Two relationships are essential: one for the net radiation and one for the total energy absorption at the surface. We prove that the net equation (Houghton 1977, Eq. 2.13) is valid on the CERES EBAF Edition 2.8 (2017) with a difference of 0.6 Wm-2 in the clear-sky global mean; the equation connects net radiation at the surface unequivocally to half of OLR independently of the optical depth and casts a strict constraint on the hydrological cycle. This equation ought to be the cornerstone of Chapter 8 (Water Cycle Changes) as well. The total energy at the surface is described by Houghton (1977, Eq. 2.15); the validity of this equation is the same as that of the net equation at a particular optical depth of 2, and defines surface energy flows (including the greenhouse effect) as a function of TOA radiation. The all-sky version of these two equations can easily be constructed. Their verification on the NEWS (2015) all-sky global mean data is within 1.5 Wm-2, and the four equations together, on the most recent 22-yr CERES EBAF Edition 4.1 have a mean bias of -0.0016 Wm-2. This accuracy establishes these equations as the physical science basis of all global energy budget studies. — There is a solution of these four equations as a set of small integers relative to LWCRE = 1. We give a complete account of Earth's energy flow system in terms of this solution. Further readings:

EGU 2021 Sir John Houghton

AMS 2022 Kevin Trenberth Symposium

AMS 2022 Conference on Atmospheric Radiation

CERES 2021 Science Team Meeting

CERES 2022 Science Team Meeting