Earth's Radiative Energy Imbalance and Climate Sensitivity calculations
(change values in the yellow cells, then press the Tab key ↹ to recalculate)


Dataentry 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 (ECSTCR), Ufract 





Fraction of (Fcd% of) ECS realized, Fr 




(1/ETratio) + ((1Ufract)×((ETratio1)/ETratio)) 
Fraction of (Fcd% of) ECS unrealized ("in the pipe") 




1  Fr 






Actual realized warming to date since LIA (1780). Wtd 

°C 


Law dome ice cores show CO2 level was 280 ppmv in 1780 
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 


Wc / Fcd (corrected 9/9/2023) 
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 


NCA4 Global Mean Energy Budget of Earth 
Crosscheck radiative imbalance & unrealized warming estimates: 

Unrealized warming calculated from assumed 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 

