Earth's Radiative Energy Imbalance and Climate Sensitivity calculations
Data-entry cells are yellow my best estimates alternative scenarios
Calculated cells are blue alarmist skeptic
value units value value references & notes
Starting CO2 level ppmv Preindustrial / LIA (1751) level is usually estimated to have been 277 - 280 ppmv
Current CO2 level ppmv https://sealevel.info/co2.html
Current CO2 forcing, as fraction of a doubling, Fcd log2( current_CO2_level / starting_CO2_level )
For all the rest of the input fields, higher values are "more alarmist," and lower values are "more skeptical."
ECS / TCR, ETratio Lewis & Curry, 2018
IPCC AR5 WG1 Table 9.5, p.818
Unealized portion of (ECS-TCR), Ufract
Fraction of ECS realized, Fr (1/ETratio) + ((1-Ufract)×((ETratio-1)/ETratio))
Fraction of ECS unrealized ("in the pipe") 1 - Fr
Actual realized warming to date since LIA (1750). Wtd °C
Anthropogenic fraction of warming to date, Fa
Assumed natural warming since LIA, Wn °C Wn = (1 - Fa) × Wtd
Fraction of anthropogenic warming that's from CO2, Fc https://gml.noaa.gov/aggi/
Realized warming since LIA due to CO2 alone, Wc °C Wc = Wtd × Fa × Fc
Expected equilibrium warming from CO2 alone, Ec °C Ec = Wc / Fr
Realized warming since LIA due to CO2 + other anthro, Wa °C Wa = Wtd - Wn ≡ Wc / Fc
Expected equilibrium warming due to CO2 + other anthro, Ea °C Ea = Wa / Fr (assuming same % unrealized for CO2 and other GHGs)
Expected equilibrium warming (natural+CO2+other GHGs), Ew °C Ew = Ea + Wn (assuming natural warming component will be unchanged)
Practical climate sensitivity (between ECS & TCR), S °C Ec / Fcd
ECS °C https://sealevel.info/glossary.html#ecs
TCR °C ECS / ETratio
Radiative forcing from a doubling of CO2, RFd W/m² https://sealevel.info/Radiative_Forcing_synopsis.html
Equilibrium warming per W/m² forcing, Ef °C/(W/m²) ECS / RFd
Remaining unrealized warming "in the pipe", Wu °C Ew - Wtd
Radiative Imbalance calculated from unrealized warming W/m² Wu / Ef
Radiative imbalance (assumed), Ri W/m² NASA / Trenberth energy budget 2014 (0.6)
Cross-check radiative imbalance & unrealized warming estimates:
Unrealized warming calculated from radiative imbalance, Ri °C Ri × Ef (compare this with Wu)
Note: "other anthro" means other anthropogenic forcings, including other GHGs, and aerosol / particulate pollution abatement
Contact: Dave Burton https://sealevel.info/contact.html
This web page was created from a MS Excel spreadsheet using WebWorksheet: https://webworksheet.com
The shreadsheet (source .xlsx file) can be downloaded here: https://sealevel.info/radiative_imbalance.xlsx