A 500-million-year survey of Earth’s climate reveals dire warning for humanity

by P. Voosen, May 22, 2019 in AAAS/Science

When it opens next month, the revamped fossil hall of the Smithsonian Institution’s National Museum of Natural History in Washington, D.C., will be more than a vault of dinosaur bones. It will show how Earth’s climate has shifted over the eons, driving radical changes in life, and how, in the modern age, one form of life—humans—is, in turn, transforming the climate.

To tell that story, Scott Wing and Brian Huber, a paleobotanist and paleontologist, respectively, at the museum, wanted to chart swings in Earth’s average surface temperature over the past 500 million years or so. The two researchers also thought a temperature curve could counter climate contrarians’ claim that global warming is no concern because Earth was much hotter millions of years ago. Wing and Huber wanted to show the reality of ancient temperature extremes—and how rapid shifts between them have led to mass extinctions. Abrupt climate changes, Wing says, “have catastrophic side effects that are really hard to adapt to.”

But actually making the chart was unexpectedly challenging—and triggered a major effortto reconstruct the record. Although far from complete, the research is already showing that some ancient climates were even more extreme than was thought.