Posts Tagged ‘very elevated extinction rates’
A century ago, we started the Sixth Great Extinction. And the human? Could he survive this massive wiping out of species?
Posted on: June 29, 2015
Sixth Great Extinction? And the human? Could he survive?
Apparently, in the last half a billion years, earth witnessed 5 extinction of its species due to natural calamities.
This current extinction process is mainly due to the human species.
There are very few extinctions that we know about in the last 100 years that would have taken place without human activity.
I have never heard anyone argue, “oh extinction rates, that’s just a natural thing that would have happened with or without humans.” It’s just pretty much impossible to argue that.
The current extinction rate could be more than 100 times higher than normal—and that’s only taking into account the kinds of animals we know the most about.
Earth’s oceans and forests host an untold number of species, many of which will probably disappear before we even get to know them
The new study that’s generated so much conversation estimates that as many as three-quarters of animal species could be extinct within several human lifetimes, which sounds incredibly alarming
What is clear, and what is beyond dispute, is that we are living in a time of very elevated extinction rates, on the order that you would see in a mass extinction, though a mass extinction might take many thousands of years to play out.
Island populations are very vulnerable to extinctions for a couple of reasons.
1. They tend to have been isolated. One of the things we’re doing is removing the barriers that used to keep island species isolated. New Zealand had no terrestrial mammals. Species that had evolved in the absence of such predators were incredibly vulnerable. A staggering number of bird species have already been lost on New Zealand, and a lot of those that remain are in deep trouble.
2. We brought in invasive species. So, places that have been isolated for a long time are very vulnerable. Species that have a very restricted range, that exist only in one spot in the world, those tend to be extremely vulnerable. They have nowhere to go and if their habitat is destroyed, say, then they’re gone.
We are now changing the climate, very rapidly, by geological standards.
We are changing the chemistry of all the oceans.
We are changing the surface of the planet.
We cut down forests,
we plant mono-culture agriculture, which is not good for a lot of species.
We’re overfishing. The list goes on and on.
We dump nitrogen on fields in the Midwest and the fertilizer runs down the Mississippi and into the Gulf of Mexico, and that causes these dead zones.
The sort of fundamental question is, can 9 billion people —live on this planet with all of the species that are now still around?
Or are we on a collision course, in part because we consume a lot of resources that other creatures also would like to consume? That’s a question I can’t answer.
If you give vertebrate species (and we are another vertebrate species) an average lifetime of a million years, and you say humans are 200,000 years into their million years, and you precipitate a mass extinction—even laying aside the question of whether humans will be the victim of their own mass extinction—you can’t expect that same species to be around by the time the planet has recovered.
There are two questions that arise:
One is, OK, just because we’ve survived the loss of X number of species, can we keep going down the same trajectory, or do we eventually imperil the systems that keep people alive?
That’s a very big and incredibly serious question.
Second, even if we can survive, is that the world you want to live in? Is that the world you want all future generations of humans to live in?
That’s a different question. But they’re both extremely serious. I would say they really couldn’t be more serious
Nadia Drake, published a conversation with Elizabeth Kolbert in National Geographic , June 23, 2015
Note: I believe that, unless the atmosphere is Not highly toxic, beside the insects and rodents, two species could survive:
1. The owl who can hear a pregnant mice one meter under the snow and 300 meters away and has incredible eyesight at night (100 times that of human) and can sneak on victims listlessly .
2. The hyena who can crush and eat bones and is an excellent hunter individually and as a team.
Adonis Diaries 