User:Ldecola/sandbox

Based on monthly Mauna Loa CO2 data from 1958 March to 2013 May the mean yearly value for year t is can be estimated as
 * $$y(t) - 255 =exp(-27.2 + .0160t),$$

which corresponds to exponential growth of 1.6% per year and implies a "historical" value of about 255 ppmv.