Inverse of `atmospheric_CO2`: retrieve the year by which a given CO2
concentration is reached.
Arguments
- aCO2
Target CO2 concentration in ppm.
Value
year Approximate year (as floating point number) by which target
concentration is reached.
Details
Does not give a reasonable result for values below 317ppm, corresponding
to the year 1949, as this is where the minimum of the parabola is located
in the second order fit to the data that was used in aCO2.fct.
Examples
aCO2_inverse(420)
#> [1] 2023.267
aCO2_inverse(700)
#> [1] 2098.318
# Insensible
aCO2_inverse(100)
#> Warning: NaNs produced
#> [1] NaN
