Earth and biologic (including climatic) scientists are in a pivotal position for reading the ‘library’ of Earth’s past and present as backdrop to global modelling of past as well as future patterns (including cyclicities) of gross environmental change—marine, estuarine, terrestrial and climatic. They have the tools for deciphering the implications of climate modeling, and the globally decreasing biodiversity and carrying capacity, and to discriminate scientifically credible information from the aggressive rhetoric and willful disinformation of professional optimists. Ultimately, it is only scientists who can accurately decipher quantitatively the anthropogenic overprint (the human impact) that presently undermines the global support systems. This requires vastly improved knowledge of extinction patterns (at all scales), causes of land and sea (including deep-ocean) extinctions, reef dynamics, changes in gross ocean circulation and ecosphere collapse. Nature may display remarkable capacity for rebound but conceivably with dramatically depleted biodiversity; it need not necessarily include Homo sapiens among its constituents. Better understanding of the natural world is imperative for our longer-term survival.