Alfred Georg Hubertus Fischer (December 12, 1920 – July 2, 2017) was a German-American geologist.
[1] Among his influential work was the examination of the climate record over geological time scales and latitudinal gradients in species diversity and numbers across geological time.
He described in 1964 the phenomenon of rhythmically recurring sequences of sedimentary rock layers in some Keuper formations of the Alps, first discovered in Dachsteinkalken in the province of Salzburg.
In the 1960s he examined latitudinal variation in the fossil record and in the 1970s, he propagated the existence of global biorhythms in the fossil record and in 1977 the concept of cycles of low and high levels of biodiversity in the marine fauna over 32 million years.
[3][4][5] In 1982 he spoke in favour of the Earth's climate alternating between ice ages and warm periods due to the (Icehouse-Greenhouse concept).