In the history of our planet there have been five great mass extinctions. The first during the late Ordovician period 450 million years ago by glaciation, and the last, and most famous, at the end of the Cretaceous period 65 million years ago, when a giant asteroid six miles wide travelling at a speed of 45,000 miles per hour collided with the Earth, wiping out three-quarters of all species, including all dinosaurs.

Every animal today descended (and evolved) from organisms that survived that extinction. But we are now facing a sixth extinction in the human-dominated Anthropocene epoch. This imperative topic is brilliantly covered by Elizabeth Kolbert in her compelling book The Sixth Extinction.

Kolbert describes how the spread of modern humans and our voracious disruption of entire ecological systems has eliminated many species in the process, and with it, we are now threatening our own survival.

Not only have we brutally increased CO2 concentrations into the air by deforestation and burning of fossil fuels, but a third of it is absorbed by the sea, creating an alarming ocean acidification that is devastating and could potentially be responsible of eliminating coral reefs (ecosystems in which millions of species rely on for survival).

Of course, anthropogenic global warming (climate change) is becoming the biggest killer, not only melting the ice caps and transforming the polar regions, but also impacting tropical forests, where most species in the planet live. The introduction of invasive species and land fragmentation have also caused a decline and extinction of species.

We Homo Sapiens are causing all this. We even drove the Neanderthals, our closest ancient human relative, to extinction. And it’s likely we were also responsible for the extinction of the Homo floresiensis and the recently discovered Denisovans, two other archaic human siblings.

We can change the course and urgently protect our planet and present species to avoid total oblivion. But we must act now. This is an incredibly researched eye-opening book by Elizabeth Kolbert that I recommend.