There are a lot of things going wrong in the world, but it is difficult to downplay the ecological crises we are currently witnessing. Repeated studies have been published describing a loss of biodiversity happening at a rate never seen before. Elizabeth Kolbert’s The Sixth Extinction: An Unnatural History describes the extinctions that are occurring around us in the context of five major extinctions in Earth’s history.
Unlike so many books about environmental crises, Kolbert stays even-keeled, with a journalist’s approach to describing what, why, where, who and how. No hysterics. She begins with a bit of history about the study of extinction, which is actually rather recent. It wasn’t until the 18th century that people realized that some of the bones that they were finding belonged to animals that no longer existed. The disputes amongst the scholars of the time seem rather quaint, particularly given what most of us have learned in high school or university.
Kolbert interviews geologists, often on the sites on which they have discovered fossil evidence of prior extinctions. Earlier extinctions occurred so long ago, that the geological evidence is literally rather thin. Makes me wonder how many millimeters we may take up a million years from now.
The Sixth Extinction’s focus is on the massive extinctions we are currently witnessing, Kolbert goes to the Amazon to learn about the effects of climate change as well as habitat loss. She visits scientists in the Pacific studying coral reefs, and scientists in the Northeastern United States who have observed the disappearance of millions of bats. The primary lesson is that the Earth’s species are under so many stressors, that they simply don’t have the resilience to fight off everything. The acidification of our oceans is killing coral, a critical part of ocean ecology. Plant and animal species can’t keep up with climate change. Animal species lose resilience when the genetic pool from which they are breeding shrinks and shrinks.
Humans have been part of other species’ extinctions from the beginning. Evidence suggests that humans did have a hand in the extinction of large megafauna such as mammoths as well as species that are part of our own ancestry, like Neanderthals. It isn’t that humans are particularly murderous, it’s more a function of not fully understanding other species’ needs, nor the consequences of interfering with natural systems. Kolbert’s future looks bleak, but she stays cool. The earth will survive even if existing species don’t. The Earth probably has millions of years left for life to evolve once again. The future for humans appears to be considerably shorter.