W:\html\sealevel\CO2_Residence_Times>perl4 calc_est_co2_removal_rates_v06.pl 
Simulated CO2 level, starting at 427.35 ppmv in 2025, and zero emissions,
per Dr. Roy Spencer's 2023 version Simple Model. Reference:
Spencer, RW (2023). ENSO Impact on the Declining CO2 Sink Rate. J Mari Scie 
Res Ocean, 6(4), 163-170, https://doi.org/10.33140/jmsro.06.04.03

Equilibrium CO2 level is 293.60, half-way down to that is 360.48 ppmv.
Half-life is 34.66 years, e-folding lifetime (adjustment time) is 50.00 years.
YEAR  CO2
2025  427.4
2026  424.7
2027  422.1
2028  419.5
2029  417.0
2030  414.5
2031  412.1
2032  409.7
2033  407.4
2034  405.1
2035  402.9
2036  400.7
2037  398.6
2038  396.5
2039  394.4
2040  392.4
2041  390.4
2042  388.5
2043  386.6
2044  384.7
2045  382.9
2046  381.1
2047  379.4
2048  377.6
2049  376.0
2050  374.3
2051  372.7
2052  371.1
2053  369.6
2054  368.0
2055  366.6
2056  365.1
2057  363.7
2058  362.3
2059  360.9
** date 2059.7: One half-life (34.7 years) reached **
2060  359.5
** 360.5 ppmv: half of the 133.8 ppmv CO2 above equilibrium is gone **
2061  358.2
2062  356.9
2063  355.7
2064  354.4
2065  353.2
2066  352.0
2067  350.9
2068  349.7
2069  348.6
2070  347.5
2071  346.4
2072  345.4
2073  344.3
2074  343.3
** date 2075.0: e-folding life (50.0 years) and level (342.80 ppmv) reached **
2075  342.3
2076  341.3
2077  340.4
2078  339.4
2079  338.5
2080  337.6
2081  336.7
2082  335.9
2083  335.0
2084  334.2
2085  333.4
2086  332.6
2087  331.8
2088  331.1
2089  330.3