Reply [to “Comment on ‘Climate control requires a dam at the Strait of Gibraltar’”]



In regard to the role of Mediterranean outflow water increase in initiating the last ice age and the proposal to eliminate the threat of new glaciation by a partial dam at Gibraltar, Marotzke and Adcroft question the wisdom of publishing a hypothesis “not substantiated through quantitative reasoning supported by data.” A hypothesis meeting these two requirements would have to be indicated by a well-established numerical model. By these standards, Alfred Wegener's “outlandish” continental drift hypothesis would never have been published, and the fascinating development of the Cretaceous-Tertiary impact hypothesis for extinction would have remained hidden within a narrow segment of the scientific community for many years. However, the data supporting the hypothesis of ice-age initiation [Johnson, 1997] are quite substantial, and all of the supporting data should be carefully considered before the hypothesis is rejected or accepted.