Climatologists' Dispute: Metelka Responds to Critics Over Atmospheric Heat Radiation

Czech climatologist Ladislav Metelka has published a detailed response to criticism from colleagues — associate professors Josef Šeják and Jan Pokorný — who accused the Czech Academy of Sciences' expert opinion AVex 4/2020 of violating the laws of thermodynamics.

The dispute centres on a single phrase in the document stating that roughly a third of the energy reaching Earth's surface arrives as solar radiation, while the remaining two-thirds comes as thermal radiation from the atmosphere. According to the critics, this is physically impossible: it would supposedly mean that energy appears in the atmosphere out of nowhere, and heat spontaneously flows from a colder to a warmer body — contradicting the second law of thermodynamics.

Metelka insists his opponents misread the wording. The key word is "arrives": the statement refers only to radiation flows that reach the surface, not the overall energy balance. According to the standard climatological model, two flows reach Earth's surface — visible solar radiation (about 160 W/m²) and infrared radiation from the atmosphere (about 333 W/m²). A third flow — thermal radiation emitted by the surface itself (390 W/m²) — moves upward, away from the ground, and is not part of the "incoming" flow.

According to observations from the Czech Hydrometeorological Institute (CHMI) in Hradec Králové, the share of infrared radiation reaching the surface is even higher than the global average — around 74%, with visible light accounting for only 26%. This is explained by geographic latitude: the higher the latitude, the greater the proportion of thermal radiation in the overall radiation balance. In addition, long-wave atmospheric radiation reaches the ground around the clock, whereas sunlight only does so during the day — and even then, it only begins to outweigh thermal radiation once the sun rises to about 29 degrees above the horizon.

According to statistics from the Hradec Králové station covering 2012–2025, long-wave atmospheric radiation exceeded the intensity of sunlight 83% of the time, with the opposite true in only 17% of cases. The strongest dominance of thermal radiation was recorded in December — 98% of the time — while the lowest was in June (69%). Even in summer, however, the atmosphere "gives" the ground more energy than it receives from the Sun.

Metelka emphasises that Earth's surface itself does indeed emit heat in the infrared range, but this is an outgoing flow, moving away from the ground rather than toward it — so it cannot be lumped together with the "incoming" radiation, as the two are distinct physical quantities.

As for the overall balance: on average, about 333 W/m² reaches the surface from the atmosphere, while about 390 W/m² leaves the surface for the atmosphere. The net heat flow — roughly 57 W/m² — moves from the warmer surface to the colder atmosphere, fully in line with the laws of thermodynamics. Data from Hradec Králové for 2018–2025 confirm this: the average upward flow is 376 W/m², the downward flow is 318 W/m², giving a net balance of minus 58 W/m².

Addressing the question of where the atmosphere gets the energy for its powerful radiation back toward the ground, Metelka explains that it absorbs heat coming from the surface (378 of the 390 W/m²), part of the sunlight (79 W/m²), as well as sensible and latent heat from the surface (20 and 82 W/m² respectively) — a total of 559 W/m². In return, the atmosphere radiates 343 W/m² back toward the ground and another 217 W/m² into space — a total of 560 W/m². Energy is not created out of nothing anywhere in this system; the balance fully checks out, the climatologist stresses.

Metelka does acknowledge one imprecision in the original AVex opinion — the phrase stating that "the lower layers of the atmosphere are warmer" without specifying warmer than what, which could have led to misinterpretation.

In conclusion, Metelka called on his opponents to publicly apologise for accusing the CzechGlobe institute, the Academy of Sciences and the Czech Hydrometeorological Institute of "forgery" and "falsifying climate data," describing these claims as baseless and beyond the bounds of legitimate scientific debate.

Around Prague, based on reporting by ekolist.cz