Earth's Radiative Energy Imbalance and Climate Sensitivity calculations
(change values in the yellow cells, then press the Tab key ↹ to recalculate)
|
|
| 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 |
58.5% |
|
58.5% |
58.5% |
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 (Fcd% of) ECS realized, Fr |
85.7% |
|
71.1% |
94.0% |
(1/ETratio) + ((1-Ufract)×((ETratio-1)/ETratio)) |
| Fraction of (Fcd% of) ECS unrealized ("in the pipe") |
14.3% |
|
28.9% |
6.0% |
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 |
0.11 |
°C |
-0.26 |
0.40 |
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 |
0.74 |
°C |
1.25 |
0.39 |
Wc = Wtd × Fa × Fc |
| Expected equilibrium warming from CO2 alone, Ec |
0.87 |
°C |
1.76 |
0.41 |
Ec = Wc / Fr |
| Realized warming since LIA due to CO2 + other anthro, Wa |
0.99 |
°C |
1.56 |
0.60 |
Wa = Wtd - Wn ≡ Wc / Fc |
| Expected equilibrium warming due to CO2 + other anthro, Ea |
1.16 |
°C |
2.19 |
0.64 |
Ea = Wa / Fr (assuming same % unrealized for CO2 and other GHGs) |
| Expected equilibrium warming (natural+CO2+other GHGs), Ew |
1.26 |
°C |
1.93 |
1.04 |
Ew = Ea + Wn (assuming natural warming component will be unchanged) |
|
|
|
|
|
|
| Practical climate sensitivity (between ECS & TCR), S |
1.27 |
°C |
2.13 |
0.67 |
Wc / Fcd (corrected 9/9/2023) |
| ECS |
1.48 |
°C |
3.00 |
0.71 |
S / Fr see https://sealevel.info/glossary.html#ecs |
| TCR |
1.06 |
°C |
1.67 |
0.57 |
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 |
0.49 |
°C/(W/m²) |
0.81 |
0.25 |
ECS / RFd |
|
|
|
|
|
|
| Remaining unrealized warming "in the pipe", Wu |
0.17 |
°C |
0.63 |
0.04 |
Ew - Wtd |
| Radiative Imbalance calculated from unrealized warming |
0.33 |
W/m² |
0.78 |
0.15 |
Wu / Ef |
|
|
|
|
|
|
| Radiative imbalance (assumed), Ri |
|
W/m² |
|
|
NCA4 Global Mean Energy Budget of Earth |
| Cross-check radiative imbalance & unrealized warming estimates: |
|
| Unrealized warming calculated from assumed radiative imbalance, Ri |
0.15 |
°C |
0.49 |
0.05 |
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 |
|
|