ABSTRACT

As explained in Chapter 3 (Box 3.4), early in the twentieth century, a Yugoslav astronomer, Milutin Milankovich, proposed that changes in the amount of solar radiation received at high latitudes in the Northern Hemisphere were the cause of ice ages. His ideas found little favour in Europe, and virtually none in America. Only when, from the 1960s onwards, the oceanic record revealed that there were many more than the four glacial periods recognised from the terrestrial record in Europe, did palaeoclimatologists realise that Milankovich was right after all. One of the pioneers of the oxygen isotope studies described in the previous chapter, Cesare Emiliani, summed up the irony of the revolution in opinion as follows:

the revolution in our views of the ice ages is a true revolution because it destroyed a canon that had been cast in granite half a century earlier and that had generated a seemingly unassailable mountain of field evidence. To add insult to injury, that revolution was not engineered from a study of glaciers or at least glacial remains like moraines, drift sheets, or loess deposits. It came instead from the deep-sea, which obviously has nothing to do with glaciers, and from mass spectrometry, which obviously has nothing to do with the trusted geological hammer.