Earth ECS Upper Limit using Modified Energy Budget Methods and Trend Analyses v.4

TL;DR

This paper applies a modified energy budget method with novel data processing to estimate Earth's equilibrium climate sensitivity (ECS), finding it to be significantly lower than IPCC estimates, with implications for climate modeling.

Contribution

It introduces a novel PIR process and high-frequency filtering to improve ECS estimation, demonstrating that ECS is likely lower than previous estimates and applicable to regional analyses.

Findings

ECS(global) <= 2.09°C, about 70% of IPCC AR6 estimate

The energy budget method can be reliably applied to ocean and land regions independently

Estimated ocean TCR/ECS ratio is approximately 0.71

Abstract

Earth Global and regional effective thermal "conductance" G(eff) (in W/(m^2 C) and often labeled lambda in climate research) and the related Equilibrium Climate Sensitivity (ECS) are evaluated by applying a modified version of the Energy Budget method, and using data only after 1970. By removing Periodic Interfering temperature components (using a novel PIR process) and applying high frequency filtering, an extraordinarily near linear temperature response is revealed, enhancing accurate G(eff) calculation and avoiding the pre-1970 aerosol forcing and ocean energy per area (E*) absorption uncertainties. A formal/empirical method is used to determine more reliable values of Q(t)=d[E*(Ocean.energy)]/dt . Using NOAA data, and after PIR, it is shown that: 1) The Energy Budget Method can be realistically applied to the Ocean and Land regions independently, 2) the "historical" 1980-2020 ECS(eff) values for Global, global Ocean, and global Land region values are <= 2.15, 1.67, 2.96 C/2xCO2 respectively; where the updated IPCC AR5 orthodox independent global Forcing value of 0.4 (W/m^2)/Decade and F/2xCO2= 3.7 W/m^2 were used. Uncertainty is about 10%. The Global average ECS(true) value of <= 2.09 C is 70% of the IPCC AR6 ECS estimate of 3.0 C, but 126% of the ECS(eff) value reported by Lewis (1.66 C). The estimated oceans average TCR/ECS ratio = 0.71 and the global average TCR/ECS ratio = 0.83, and ECS(land)/ECS(Ocean) = 1.77 . [Results using HADCRUT temperature data instead are similar, but 6% "cooler" over land, and 8% "warmer" over oceans.] A simplified physically realistic formal/empirical Coarse 2-D Global Climate Model is derived wherein variation of Geff(t) until equilibrium (i.e. "pattern effects") are proven to be negligible or "cooling", using these Methods. And so it is likely ECS(true)<= ECS(eff).