David Grinspoon Quote
A few times, all the world’s land surface has clumped together into one giant supercontinent, surrounded by one global ocean. Even supercontinents drift, and 450 million years ago the planet was put out of sorts when the supercontinent Gondwana drifted down over the South Pole. As this one and only huge continent completely froze over, the ice and snow piled up, miles thick. So much of the world’s water became locked into these colossal drifts that sea level plummeted. During several million years in this strange configuration, there were multiple glaciations punctuated with more mild interglacials. Both sea level and ocean chemistry fluctuated sharply, dooming many species dependent upon the disappearing and changing coastal environments. This caused the Ordovician–Silurian extinction, probably the second-most extreme mass extinction in Earth history. It seems that the perpetrator was just a series
A few times, all the world’s land surface has clumped together into one giant supercontinent, surrounded by one global ocean. Even supercontinents drift, and 450 million years ago the planet was put out of sorts when the supercontinent Gondwana drifted down over the South Pole. As this one and only huge continent completely froze over, the ice and snow piled up, miles thick. So much of the world’s water became locked into these colossal drifts that sea level plummeted. During several million years in this strange configuration, there were multiple glaciations punctuated with more mild interglacials. Both sea level and ocean chemistry fluctuated sharply, dooming many species dependent upon the disappearing and changing coastal environments. This caused the Ordovician–Silurian extinction, probably the second-most extreme mass extinction in Earth history. It seems that the perpetrator was just a series
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About David Grinspoon
His research focuses on comparative planetology, with a focus on climate evolution on Earth-like planets and implications for habitability. He has also studied, written and lectured on the human influence on Earth, as seen in cosmic perspective.
He has published four books, Venus Revealed, which was a finalist for the Los Angeles Times book prize, Lonely Planets: The Natural Philosophy of Alien Life, which won the 2004 PEN literary award for nonfiction, Earth in Human Hands, which was named one of NPR's Science Friday "Best Science Books of 2016" and Chasing New Horizons: Inside the Epic First Mission to Pluto, co-authored with Alan Stern. He is adjunct professor of Astrophysical and Planetary Science at the University of Colorado, a former Fellow of the Institute for Cross-Disciplinary Engagement at Dartmouth College and a former Distinguished Visiting Scholar in the College of the Environment at Wesleyan University.