The Intergovernmental Panel on Climate Change (IPCC) has an idea about how the Earth cools itself: when the planet’s surface warms up, it sends more heat into space as infrared radiation. They estimate that for every 1-degree Celsius increase in temperature, the Earth releases an extra 3.3 watts of energy per square meter—a natural cooling effect.
At the Earth’s average temperature of about 15°C, this balances out the heat coming in from the sun, keeping things stable. But the IPCC also says that as the planet warms, water vapour in the atmosphere increases, trapping more heat and making warming worse. This “positive feedback” leads them to predict a significant temperature rise—about 3°C—if we double the amount of CO2 in the air. But what if water vapour doesn’t always work that way?
The Intergovernmental Panel on Climate Change (IPCC) provides a foundational estimate for the Planck feedback—the increase in outgoing long wave infrared radiation (OLR) with temperature—as -3.3 W/m2/K at Earth’s average surface temperature of 288 K, where OLR is approximately 240 W/m2 (IPCC AR6, 2021). Derived from the Stefan-Boltzmann Law (j = σ T^4), this feedback means a 1 K temperature increase raises OLR by 3.3 W/m2, a 1.4% increase, acting as a natural self-cooling mechanism. Over small temperature ranges, this relationship is quasi-linear, stabilising the climate system. The IPCC, however, assumes positive feedbacks, particularly from water vapour (+1.1 W/m2/K), reduce the net feedback to -1.2 W/m2/K, leading to an equilibrium climate sensitivity (ECS) of ~3 K for a CO2 doubling (3.7 W/m2 forcing). This positive feedback narrative drives the IPCC’s CO2-centric warming projections, but what if water vapour behaves differently?
Complicating the IPCC with Miskolczi’s Radiative Equilibrium Theory
Ferenc Miskolczi’s 2023 paper challenges the IPCC’s framework by proposing that the Earth’s atmosphere maintains a constant flux optical thickness (τ ≈ 1.867), keeping OLR stable at 240 W/m2 despite rising CO2 levels. Using NOAA-R1 radiosonde data (1948–2008), Miskolczi shows that water vapour (H2O) decreases as CO2 increases (Figures 10 and 11), suggesting a negative feedback: H2O reductions make the atmosphere more transparent to LWIR, offsetting CO2’s radiative forcing. His HARTCODE simulations (Figure 9) yield an effective feedback of -2.54 W/m2/K, lower than the IPCC’s -3.3 W/m2/K due to atmospheric absorption (A = 1 – e^-τ ≈ 0.85). However, the decreasing H2O trend implies that τ may decline over time, potentially increasing the feedback closer to -3.3 W/m2/K. Miskolczi’s theory complicates the IPCC’s narrative by prioritising the hydrological cycle over CO2, suggesting that negative feedbacks dominate, potentially reducing ECS far below the IPCC’s estimate.
Comparing with Satellite Measurements: A Reality Check
Satellite measurements from AIRS and IASI (2003–2021) provide a critical test of Miskolczi’s claims. These instruments show a decreasing OLR trend of -0.05 to -0.3% per year in CO2 and CH4 spectral bands, equating to a reduction of -2.16 to -12.96 W/m2 over 18 years. By 2021, global mean OLR may have dropped to 235–238 W/m2, reflecting increased greenhouse gas trapping, which contradicts Miskolczi’s assertion of OLR stability at 240 W/m2. Additionally, AIRS estimates a clear-sky feedback of -2.2 W/m2/K, closer to Miskolczi’s -2.54 W/m2/K than the IPCC’s -3.3 W/m2/K, suggesting real-world feedbacks may be weaker due to atmospheric dynamics like clouds. However, satellites also show increasing H2O with warming, challenging Miskolczi’s negative feedback from decreasing H2O. This discrepancy highlights a tension: while Miskolczi’s framework captures some radiative balance aspects, recent observations suggest greenhouse gases are reducing OLR, aligning more with the IPCC’s view of positive feedbacks.
Proposing a New Hypothesis: Dynamic Hydrological Feedback with Regional Variability
Reconciling these perspectives, I propose a new hypothesis: the Earth’s climate system is governed by a dynamic hydrological feedback with regional variability, where the IPCC’s Planck feedback (-3.3 W/m2/K) acts as the initial stabiliser, but water vapour’s role varies spatially and temporally.
In regions where H2O decreases (as Miskolczi’s data suggests), negative feedback enhances the Planck response, potentially increasing the effective feedback to -3.3 W/m2/K or higher by reducing τ.
In contrast, regions with increasing H2O (per satellite data) exhibit positive feedback, reducing OLR and aligning with the IPCC’s narrative.
Globally, these competing effects may average to a feedback closer to AIRS’s -2.2 W/m2/K, suggesting an ECS of ~1.7 K (3.7 / 2.2), lower than the IPCC’s 3 K but higher than Miskolczi’s near-zero warming. This hypothesis accounts for satellite-observed OLR decreases while integrating Miskolczi’s insights on hydrological regulation, proposing that regional H2O trends—rather than a uniform global response—drive climate sensitivity.
Conclusion
Miskolczi’s work, particularly Figure 9, illustrates radiative transfer functions that modulate OLR, while satellite data reveals the complexity of real-world trends. My hypothesis builds on the IPCC’s -3.3 W/m2/K feedback, incorporates Miskolczi’s hydrological insights, and addresses satellite observations by emphasizing regional variability in H2O feedbacks. This perspective challenges the IPCC’s uniform positive feedback assumption and Miskolczi’s strict OLR stability, offering a nuanced view of climate regulation that warrants further research into regional hydrological dynamics.
This new hypothesis is Plank#4 of my new Theory of Climate Resilience.
This was due to be shared on Friday of this week at Substack, but taking Willis Eschenbach’s advice about being open to constructive criticism more generally, I’m putting it out a bit early and at my blog, to see what constructive criticism are thrown up in advance.
References
IPCC. (2021). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. https://www.ipcc.ch/report/ar6/wg1/.
Miskolczi, F. (2023). Greenhouse Gas Theories and Observed Radiative Properties of the Earth’s Atmosphere. Science of Climate Change, 3(3). DOI: https://doi.org/10.53234/scc202304/05.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
I am in awe of those who claim to be able to put a figure on the thermodynamic processes of a globe which has discontinuous area of oceanic surface and continental surface with very large differences in reflectivity and specific heat capacity.
It is a no-brainer that the earth discards 100% of the energy poured onto the atmosphere encased solid and aqueous globe by radiation – “empty” space surrounds us and performs extremely negligible conduction and convection.
Climate theories must account for the mechanisms which keep it in meta-equilibrium between the small temperature parameters known by observation during human times and by proxies far back in the past.