Roles of Earth’s Albedo Variations and Top-of-the-Atmosphere Energy Imbalance in Recent Warming: New Insights from Satellite and Surface Observations

Ned Nikolov and Karl Zeller

Main Conclusions

Our analysis revealed that the solar forcing (i.e., Total Solar Irradiance (TSI) and albedo changes) measured by CERES explain 100% of the observed global warming trend and 83% of the interannual GSAT variability over the past 24 years (Figure 9), including the extreme 2023 heat anomaly (Figure 10).

Albedo changes were found to be by far the dominant GSAT driver, while TSI variations only played a minor, modulating role (Figure 11 and Figure 12).

The sustained increase of sunlight absorption by the planet was also identified as the most likely driver of ocean warming in recent decades based on a high correlation (R² = 0.8) between the shortwave radiation uptake and the mean annual temperature anomaly of the 0–100 m global oceanic layer (Figure 8).

These results suggest a lack of physical reality to both the anthropogenic radiative forcing attributed to rising greenhouse gases and the positive (amplifying) feedbacks hypothesized by the greenhouse theory and simulated by climate models. This is because any real forcing (or amplifying feedback) outside of the increased planetary uptake of solar radiation would have produced additional warming above and beyond the amount explained by changes in the planetary albedo and TSI.

However, no such extra warming is observed in the available temperature records. Hence, the anthropogenic radiative forcing and associated positive feedbacks are likely model artifacts rather than real phenomena.

The empirical data and model calculations analyzed in our study also indicate that the Earth’s climate sensitivity to radiative forcing is only 0.29–0.30 K/(W m⁻²). Therefore, the greenhouse theory overestimates this parameter by 56–158%.

The lack of evidence for heat trapping by greenhouse gases in the climate system during the 21st Century raises an important question about the physical nature of the Earth’s Energy Imbalance (EEI).

The latter is defined as the difference between the absorbed shortwave and outgoing LW flux at the TOA. EEI has been observed and calculated by various monitoring platforms for several decades.

This index became a research focus in climate science during the past 15 years, because it has been perceived as evidence of anthropogenic heat accumulation (energy retention) in the Earth system that would commit the World to a prolonged future warming, even after human carbon emissions have reached a net-zero level. As a result of such a view, EEI is now called the “most fundamental indicator for climate change” [33].

However, our analysis of observed data, model calculations, and standard thermodynamic theory showed that EEI has been misinterpreted by the science community, since it arises from adiabatic dissipation of thermal energy in ascending air parcels in the troposphere due to a decreasing atmospheric pressure with height (see discussion in Section 4).

Hence, integrating EEI over space and time in an effort to calculate some total “energy gain” by the Earth system, as done by researchers in recent years, is physically misleading, because EEI includes energy that was adiabatically lost to the system during the convective cooling process.

Our analyses also showed that this energy imbalance results from a varying sunlight absorption by the planet and would only disappear if the Earth’s albedo stops changing and the uptake of shortwave radiation stabilizes, which is unlikely to ever occur.

The reduction of human greenhouse-gas emissions cannot and will not affect EEI. Nevertheless, the Earth has gained a considerable amount of thermal energy over the past 45 years due to a sustained increase of shortwave-radiation uptake, which is a completely different mechanism from the theorized trapping of radiant heat by greenhouse gases, since it does not involve a hidden energy storage.

These findings call for a fundamental reconsideration of the current paradigm of understanding about climate change and related socio-economic initiatives aimed at drastic reductions of industrial carbon emissions at all costs.

An important aspect of this paradigm shift should be the prioritized allocation of funds to support large-scale interdisciplinary research into the physical mechanisms controlling the Earth’s albedo and cloud physics, for these are the real drivers of climate on multidecadal time scales.

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