by Planet B
While the baseline presence of CO2 is undeniably a primary driver of the atmosphere’s natural greenhouse effect- keeping the planet warm enough to sustain life – the real scientific debate isn’t about its existence, but its marginal climate sensitivity at higher concentrations.
However, as demonstrated by researchers like Schnell and Harde, the radiative forcing of CO2 is strictly logarithmic.
The first few hundred parts-per-million do the heavy lifting. Once those absorption bands are highly saturated, adding more gas yields massive diminishing returns. In fact, their modeling shows that even pushing concentrations to an extreme 100,000 ppm fails to trigger runaway, catastrophic warming because the incremental thermal effect drastically plateaus. The panic button is being smashed over what amounts to a birthday candle’s worth of additional heat capacity.
.Furthermore, assuming CO2 is the only dial controlling modern temperature variations ignores major satellite data. For instance, Nikolov & Zeller (2024) analyzed NASA’s CERES satellite data and found that a distinct decrease in Earth’s planetary albedo (cloud reflectivity) over the last two decades allowed the planet to absorb more direct solar radiation. According to their analysis, this shift in absorbed sunlight accounts for the recent warming trend—proving that natural variations in solar absorption are doing the heavy lifting while commentators remain hyper-fixated on CO2..