How many species have humans put out of business?
January 17, 2015 7:23 PM Subscribe
A colleague of mine says humans have caused the extinction of "millions of species," but that strikes me as hyperbole. Can you point me to any credible sources on this question?
I'm aware of the recent study that concludes extinction in the human era is accelerating far beyond the natural extinction rate (x1000 seems to be the standard figure). But does anyone know of solid science that to support the claim that humanity had made "millions" of species extinct?
I'm aware of the recent study that concludes extinction in the human era is accelerating far beyond the natural extinction rate (x1000 seems to be the standard figure). But does anyone know of solid science that to support the claim that humanity had made "millions" of species extinct?
That's "Holocene" not holocebe. Also "anthropocene extinction." And the article that Wiki cites for the 140k a year stat is this one: Close[2] S.L. Pimm, G.J. Russell, J.L. Gittleman and T.M. Brooks, The Future of Biodiversity, Science 269: 347–350 (1995)
posted by feets at 8:07 PM on January 17, 2015
posted by feets at 8:07 PM on January 17, 2015
It's not certain, but it's very possible. There are somewhere around 8.7 million eukaryotic species on earth (not counting prokaryotes like bacteria and archea, so add in a few more million if you want to count those). Statistical analysis seems to indicate a rate of 100 to 1,000 species lost per million per year, mostly due to human-caused habitat destruction and climate change.
So doing that math, that's 0.01% to 0.1% of species lost each year, or somewhere between 8,700 and 87,000 eukaryotes annually.
But for how long a period should that be looked at? The pace of human expansion and climate change has obviously been accelerating recently. One possibility might be looking at the past 40 years, a period during which it's estimated that earth has lost half its wildlife.
So, if we extend the numbers out over the past four decades, during that period somewhere between 348,000 and 3,480,000 eukaryotic species were driven extinct, primarily by human-related causes.
So "millions" is not absolutely guaranteed, but it's not hyperbole and is a perfectly reasonable estimate. An estimate of 2 million would be just about smack in the middle of the likely statistical range.
posted by kyrademon at 3:15 AM on January 18, 2015
So doing that math, that's 0.01% to 0.1% of species lost each year, or somewhere between 8,700 and 87,000 eukaryotes annually.
But for how long a period should that be looked at? The pace of human expansion and climate change has obviously been accelerating recently. One possibility might be looking at the past 40 years, a period during which it's estimated that earth has lost half its wildlife.
So, if we extend the numbers out over the past four decades, during that period somewhere between 348,000 and 3,480,000 eukaryotic species were driven extinct, primarily by human-related causes.
So "millions" is not absolutely guaranteed, but it's not hyperbole and is a perfectly reasonable estimate. An estimate of 2 million would be just about smack in the middle of the likely statistical range.
posted by kyrademon at 3:15 AM on January 18, 2015
... I'm sorry, I just realized that my math is wrong. 100 to 1,000 per million per year means, for a group of 8.7 million, 870 to 8,700 per year, not ten times that.
That means over 40 years, the loss would be somewhere between 34,800 and 348,000 species.
If correct, that means that "millions" would indeed be a hyperbole, even if you increase the period looked at considerably, although "hundreds of thousands" very likely would not.
Many apologies for screwing up the math initially.
posted by kyrademon at 6:14 AM on January 18, 2015 [2 favorites]
That means over 40 years, the loss would be somewhere between 34,800 and 348,000 species.
If correct, that means that "millions" would indeed be a hyperbole, even if you increase the period looked at considerably, although "hundreds of thousands" very likely would not.
Many apologies for screwing up the math initially.
posted by kyrademon at 6:14 AM on January 18, 2015 [2 favorites]
This article looks at the difficulties in estimating species loss and gives some context to the numbers.
posted by Busy Old Fool at 8:16 AM on January 19, 2015
posted by Busy Old Fool at 8:16 AM on January 19, 2015
« Older Is it even possible to "date" anymore? | Square + IFTTT(?) + ____ = When should I close up... Newer »
This thread is closed to new comments.
posted by feets at 7:33 PM on January 17, 2015 [1 favorite]