THE SIXTH EXTINCTION: An Unnatural History examines the notion of extinction, which turns out to be a surprisingly recent concept. Thomas Jefferson fully expected Lewis and Clark to find mastodons roaming the wild west. The assumption was that God's creations were permanent. It wasn't until 1796 that scientists were persuaded otherwise by the work of the French naturalist Cuvier.
Modern research has documented five previous periods of mass extinction, defined as the loss of a significant part of all life on the planet in a relatively short period of time. Some are due to external events, most famously the 6-mile wide meteor that struck earth about 65 million years ago. Others are attributed to lava flows, glaciers or earlier bouts of global warming.
Extinctions are nothing new. What is new and different about the sixth extinction is that it is man-made. Climate change due to global warming is a huge factor, especially for marine life. But so is the impact of 7 billion people competing for habitat. The heavy footprint of mankind on the planet is crushing out competing life forms at a rate far above normal -- by one estimate, 10,000 times the natural rate in the tropics. Fifty percent of all living species are facing possible extinction by the end of this century.
Cities spread relentlessly across open land and into the oceans and rivers. Forests are destroyed to feed our ever-growing appetites for animals, vegetables, and minerals. And you can add illicit drug growers to the list of forest killers as well. Ships carry invader species to fertile new hunting grounds; Kolbert writes that supertankers move an estimated 10,000 species a day around the world. Diseases are spread among animals with the same devastating effects as any global flu pandemic on humans. Our pathetic quest for longer sexual arousal has brought several species to the brink of extinction.
Life prospered when the exchange of carbon and oxygen was mastered over millions of years. Now we use the atmosphere as the dumping ground for billions of tons of carbon generated through the burning of fossil fuels and cement production. About half of that carbon returns to the sea, where it makes the water more acidic, with devastating effects on coral and the phytoplankton that make up the bottom rung of the ocean's food chain.
None of this is breaking news. Those of us who see climate change as a clear and present danger -- we're dismissed as global warming alarmists by those who deny its existence -- have been sounding the warning bell for several decades now. Politicians like to deal with difficult issues by pushing them off into the future, so it's no surprise that governments have largely ignored the warnings on climate change and over-population, choosing instead to burn our fossil fuel candle at both ends while paying lip service to reform. But the future has a nasty habit of arriving when we seem to least expect it. And by the time we figure out that the future is now, it is usually too late to alter whatever fate has in store for us.
I have always maintained that if you want to judge fairly who is right about the impact of climate change and human population growth on the planet then don't ask a pundit or a politician or even a scientist. Seek out instead the birds overhead or the beetles underground or the fish in the seas or the wildlife that live on the mountains and the plains.
They have no political agenda. They belong to no party. They merely do what they have to do to adapt to a changing environment .... or they die. And right now they are dying in record numbers. That's on us. The only question is when we will join the roster of the sixth extinction, for make no mistake about it, that is where we are headed. We are killing the planet that supports all life, including ours. We instinctively turn away from that thought, confident that we can trick Mother Nature one more time, but sooner or later it has to catch up with us.
Kolbert quotes Pope Francis during an interview. I'll give his entire quote here:
I wish to mention another threat to peace, which arises from the greedy exploitation of environmental resources. Even if ‘nature is at our disposition’, all too often we do not ‘respect it or consider it a gracious gift which we must care for and set at the service of our brothers and sisters, including future generations’. Here too what is crucial is responsibility on the part of all in pursuing, in a spirit of fraternity, policies respectful of this earth which is our common home. I recall a popular saying: ‘God always forgives, we sometimes forgive, but when nature – creation – is mistreated, she never forgives!’.I'll close with another quote, this one from Loren Eiseley, another great writer and explorer of the natural world: “If it should turn out that we have mishandled our own lives as several civilizations before us have done, it seems a pity that we should involve the violet and the tree frog in our departure."