“How do you know we’re the only time there’s been a civilization on our own planet?” [said Goddard Institute for Space Studies director Gavin Schmidt].
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[T]hat first conversation launched a new study we’ve recently published in the International Journal of Astrobiology. Though neither of us could see it at that moment, Gavin’s penetrating question opened a window not just onto Earth’s past, but also onto our own future.…
[C]ould researchers find clear evidence that an ancient species built a relatively short-lived industrial civilization long before our own? Perhaps, for example, some early mammal rose briefly to civilization building during the Paleocene epoch about 60 million years ago.…
Fifty-six million years ago, Earth passed through the Paleocene-Eocene Thermal Maximum (PETM). During the PETM, the planet’s average temperature climbed as high as 15 degrees Fahrenheit above what we experience today.
Related on the SLP
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Are these events indications of previous nonhuman industrial civilizations? Almost certainly not.
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Gavin and I don’t believe the Earth once hosted a 50-million-year-old Paleocene civilization. But by asking if we could “see” truly ancient industrial civilizations, we were forced to ask about the generic kinds of impacts any civilization might have on a planet. That’s exactly what the astrobiological perspective on climate change is all about.
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