According to a new study published in Science, abrupt climate change was part of the one-two punch that killed off most of the Earth’s mammalian megafauna, such as the wooly mammoth and wooly rhinoceros. A series of rapid warming events, called interstadials, happened between 60,000 and 12,000 years ago, and coincided with extinction events even before the rise of humans.
These rapid warming events, which closely resemble the kind of human caused rapid warming that we see today, caused dramatic shifts in global rainfall and vegetation patterns. This new research is especially helpful in explaining the disappearance of mammoths and giant sloths around 11,000 years ago.
While the warming periods changed the world dramatically and set in motion the extinction events that saw the end of wooly mammoths and others, it was the rise of humans that actually sealed the deal. These populations were already under significant ecological stress as their natural habitats changed faster than they could keep up. Human impacts, namely in the form of overhunting creatures like wooly mammoths, hastened their extinction.
This new data, which was collected thanks to improvements in radiocarbon dating and the analysis of ancient DNA, has shed light on the geological period in question, and will allow scientists to more accurately analyze the period of Earth’s past in which humans first began to rise to dominance.
It also acts as a warning. Human activity is causing rapid climate change, which mirrors the kinds of global changes recorded in earlier geographic eras. The interstadials of the last glacial ice age may not have been caused by humans, but they still helped to wipe out numerous species that had been prominent before that. Our own actions today are changing the environment more rapidly than we can cope with it, and if we’re not careful, those changes could spell the end of many more species before we get things under control.