Ah, Fantastic! He led the creation of the field of climatology if I recall.

If someone can do forecasting of AGI with similar empiricism that would be revolutionary and welcomed.

Arrhenius probably did no empirical research in this field. He devised a generalized formula based on theoretical considerations and indirect measurements (of the moon's appearance). It would take ~60 years before a quorum of researchers believed his formula could provide accurate real-life predictions.

Moravec's 70s papers are roughly comparable to Arrhenius's formula. The basic computational power predictions (a minor extension of Moore's law) still seem to be basically correct. There's a reasonable debate to be had about whether more interesting predictions made by Moravec/Kurzweil/etc. have been validated or not.