Thursday 25 March, 4 PM CET
Abstract: Tropical species appear to live near their upper thermal tolerance raising major concerns and questions about how tropical species will fare on a warming planet. Yet, estimates for tropical temperatures in the warmest parts of the Eocene and Cretaceous are often more than 10C greater than today for many millions of years, and fossils are known from tropical localities during these times. The fossil record thus raises the potential that that modern estimates of thermal tolerance reflect the thermal range of the modern world, rather than an absolute physiological limit. To date, temperature proxy uncertainty has limited our ability to constrain the amount of low latitude warming (relative to deep sea or global warming), as has the difficulty of extrapolating heat stress from temperature. In this talk, I will present and discuss a new compilation of sea surface temperatures for the last 95 million years, as it related to tropical heat stress and the existence of potentially impending physiological limits to life in the tropics.