SIXTH EXTINCTION: The Panamanian golden frog, pictured here, is extinct, thanks to a lethal combination of habitat destruction, climate change and a fungal disease.
Image: Jeff Kubina
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The Best Science Writing Online 2012
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It’s an uncomfortable thought: Human activity causing the extinction of thousands of species, and the only way to slow or prevent that phenomenon is to have smaller families and forego some of the conveniences of modern life, from eating beef to driving cars, according to Stanford University scientists Paul Ehrlich and Robert Pringle.
This extinction—the sixth in the 4-billion-year history of the Earth—"could be much more catastrophic than previous ones," says Ehrlich, author of the controversial Population Bomb, which predicted that hundreds of millions of people would starve to death in the 1970s. That fate was forestalled by the green revolution in Asian agriculture, in which new strains of cereal crops plus enhanced use of fertilizer and irrigation allowed farmers to grow enough food to feed a burgeoning population. But this is a new threat: "Anything in the vicinity of the previous ones," Ehrlich says, such as the mass extinction at the end of the Cretaceous that killed half of all species, including the dinosaurs, "would wreck civilization."
Right now, at least 2,000 frogs, salamanders and other amphibians are in danger of going extinct, according to a survey by biologists David Wake and Vance Vredenburg, writing in the Proceedings of the National Academy of Sciences USA. Coastal seas and estuaries have lost as much as 91 percent of certain species, such as oysters, according to another survey. And nearly 50 percent of all temperate grasslands and forests have disappeared.
But through it all the species responsible for this change—through overuse, pollution and other impacts—has continued to thrive and multiply, reaching roughly 6.7 billion in population and counting.
"The fate of biological diversity for the next 10 million years will almost certainly be determined during the next 50 to 100 years by the activities of a single species," write Ehrlich and Pringle in their proposal for addressing the biodiversity crisis. Adds Pringle: "The world's remaining wild areas and the species in them are being pulverized, and that's a multi-layered tragedy."
That’s why Ehrlich and Pringle call for educating women, which has slowed or stopped population growth in the developed countries of Europe. "Education and employment—for women especially—along with access to contraception and safe abortions are the most important components," they write. Adds Ehrlich: "The most basic response is to get going on stopping population growth and starting a decline. Second is doing something about consumption. If you don't do anything about those, then you are in trouble in all the others: more people, means more greenhouse gases, which means more rapid climate change."
A series of studies in PNAS detail the extent of the sixth extinction. As of the end of last year, more than 16,000 species faced extinction and 785 had already been lost, according to the International Union for the Conservation of Nature. But biologist E. O. Wilson notes that most species remain to be discovered and may be winking out without humans noting their passing; he estimates that at least 12,000 species are dying out every year.
Amphibians are among the most threatened thanks to a lethal combination of climate change, habitat destruction and a deadly fungal infection (chytridiomycosis)—and many unique species, including frogs that reared their young in their own stomachs from Australia, have already disappeared. In fact, last year's prediction by the U.N. Intergovernmental Panel on Climate Change that amphibians who lived on mountainsides would increasingly go extinct is now reality.
Meanwhile, human use of sea life, particularly overfishing, has emptied the oceans. Longline fishing records reveal that nearly 90 percent of pollock and haddock have disappeared in the last century and cod alone has decreased by 96 percent since 1852. Large sharks continue to dwindle while other species, such as clam-eating cownose rays, have exploded in the absence of predators. Jellyfish are among the only living things to thrive in the oxygen-starved waters of expanding dead zones. Even the Great Barrier Reef has living coral on only 23 percent of its surface, one-half of levels in 1980.
With the human population growing—predicted to reach 9.3 billion by 2050—along with the need for more food, more goods and more resources, the outlook for other species seems grim. But the outlook is also troubling for humans, note Ehrlich and Pringle. In particular, humanity relies on the services provided by the natural world for free, such as clean water. Then there are the bees: Regardless of whether honeybees become extinct as a species as a result of colony collapse disorder, climate change and other threats, the local extinction of various honeybee populations and the pollination they provide could spell disaster for human agriculture.
As a result, Ehrlich and Pringle also call for endowments to perpetually fund conservation areas, such as the Paz Con la Naturaleza initiative under consideration in Costa Rica that would generate $500 million in one-time money from taxpayers and be used to fund conservation in perpetuity for the national park system.
They also call for making agricultural land more hospitable to wildlife, recognizing the economic value of various ecosystem services like pollination and returning degraded lands to a natural state to help stave off this biodiversity crisis, with its attendant effects on humanity. "There are desperately poor people surrounding many of these reserves," Ehrlich notes. "If I was there, I would shoot the hippo and eat it too."
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22 Comments
Add CommentHelp the honeybees! Prevent the loss of the world food supply.
Reply | Report Abuse | Link to thisLearn how you can help cure Colony Collapse Disorder. What is the bee tree?
thebeetree(dot)org
Erlich hasn't been right about anything yet. In fact, the historical record suggests you wouldn't go too far wrong by assuming the OPPOSITE of his position and proceeding accordingly.
Reply | Report Abuse | Link to thisSo why are we still listening to this guy?
Sure, let's party and breed like rabbits.
Reply | Report Abuse | Link to thisReligion hasn't been right about anything - yet you and millions believe in it.
Reply | Report Abuse | Link to thisSo you're saying we should party and breed like rabbits?
Remember George Carlin's comment: the planet isn't in trouble, it's the people who are screwed up. Sooner or later the planet will shake us off like a bad case of fleas. ---- But just take a deep breath and get over the habit of attacking people whose opinions differ or who have not been right in the past. In The Population Bomb, Ehrlich was predicting that if something didn't change, people would be starving by now. OK, something did change, but it wasn't what he could have expected. What will head off this next potential catastrophe? War? Epidemic? Or people finally acting sensibly? Or some scientific miracle?
Reply | Report Abuse | Link to thisWell, no, I'm not saying that at all. What I'm saying is that Erlich has a history of making wildly inaccurate predictions, which in any sane world would tend to falsify his hypotheses. To the extent that his new predictions are based on similar models, they ought to be received with a very large grain of salt, if not simply kicked to the back of the bus in favor of models whose predictions manage to pass the all-important reality test.
Reply | Report Abuse | Link to thisReligion offers no falsifiable propositions, whereas Erlich made TONS of those in TPB, so I don't really see the connection.
Regarding breeding like rabbits, reference the past four decades of research that establish that affluent populations do NOT do so... and the world is becoming more affluent every day.
I don't know anything about Ehrlich other than what I've read here in both the SA article and the comments that followed. However, in all the discussion about the damage mankind is doing to Mother Earth, essentially no one is discussing the need for mankind to take its leave of this planet and get out into the real world of the universe, establishing new homes.
Reply | Report Abuse | Link to thisMothers are of two minds when it comes to the futures of their children - they would like them to stay at home, but they also want them to have their own families and homes, providing a deserved rest from the rearing process, as well as more progeny. Mother Earth is the same. She's getting tired of her kids and their antics. It's time for them to move out and fend for themselves. She'll be glad to have them visit from time to time, but when it's time to get some rest, she would really like to have the peace and quiet that comes when she sees the taillights of their car going down the road that takes them to wherever they have resettled.
I don't know anything about Ehrlich other than what I've read here in both the SA article and the comments that followed. However, in all the discussion about the damage mankind is doing to Mother Earth, essentially no one is discussing the need for mankind to take its leave of this planet and get out into the real world of the universe, establishing a new home. Mothers are of two minds when it comes to the futures of their children - they would like them to stay at home, but they also want them to have their own families and homes, providing a deserved rest from the rearing process. Mother Earth is the same. She's getting tired of her kids and their antics. It's time for them to move out and fend for themselves. She'll be glad to have them visit from time to time, but when it's time to get some rest, she would really like to have the peace and quiet that comes when she sees the taillights of their car going down the road that takes them to wherever they have resettled.
Reply | Report Abuse | Link to thisWomen are not going to do this, and all we are seeing right now is the evolutionary extinction of famales lacking the most extreme motherhood drive. Arguing with evolution is not productive. So do the math on what will follow. If lower reproduction rate is linked to intelligence, that's the evolutionary ball game, right there.
Reply | Report Abuse | Link to thisAs for the ridiculous contentions that Ehrlich is wrong, just look around.
- Global warming caused by human CO2 and other greenhouse gas production.
- World grain reserves at an all time low.
- Food prices causing mass starvation. But oh, dear, since those people don't have access to the media, and starvation rapidly results in death as well as inability to function, don't hear that much from them.
I could go on.
Ehrlich's suggestion is ridiculous, and easily proven to be unworkable from obvious mathematical modeling.
Evolution is an entirely negative process. It is easily shown that evolution is favoring women who are rapid reproducers. Within the developed world this is it is favoring women that have an extremely strong motherhood drive. That feeds into the standard Hardy-Weinberg evolutionary genetics equation. It means that within 3-5 generations, those women with low motherhood drive will be virtually extinct, and those with extreme motherhood drive will 99%+ of the population.
Reply | Report Abuse | Link to thisEvolution favoring women who respond to pressures by lower reproductive rates is a group survival phenomenon. Lower reproductive rates were favored for bands and tribes that did not overwhelm their local habitat and therefore starve to death as a group. Since this means that many groups did overwhelm their habitat and starve, the fact that our world is pretty close to one big tribe now should give us serious pause.
So Dr. Ehrlich's recipe for survival will not work. In fact, it should accomplish a more rapid explosion over the multi-generational span in which this evolution will take place.
Er... okay, since your alleged "mass starvations" don't show up in any media, precisely what evidence do you have that they exist at all? I imagine the recent increases in food prices have affected the numbers on the margin... but that isn't quite the same thing, is it?
Reply | Report Abuse | Link to thisI'm not sure why it's "ridiculous" to point out that Erlich has been wrong in the past. And not just marginally wrong... ENTIRELY wrong, both qualitatively (he predicted mass starvations, while the hunger situation has actually improved dramatically since he published TPB) and quantitatively (he predicted runaway population growth, while global population growth has actually slowed considerably).
Amazingly, TPB is still in print. Why not pick up a copy and actually READ the thing? Compared with Erlich's dire predictions, current conditions pretty much speak for themselves. If Erlich ever had to put his money where his mouth is, HE'd have starved long since.
This is the Hardy-Weinberg equation for a trait with two alleles with fractions of the total population, of p and q.
Reply | Report Abuse | Link to thisp + q = 1 (By definition, this is true, since each has one or the other.)
(p + 1)^2 = p^2 + 2pq + q^2 (If p is dominant allele then p^2 is fraction of those with both alleles of the dominant. 2pq is the mixes, and q^2 is the recessive fraction.) Also, p^2 + 2pq + q^2 = 1. (Just like the first equation. The total population is always represented by 1, exactly like the total for anything represented as a percentage is always represented by 100%.)
Now, if you set the calculation up so that you iterate it, and each generation you remove 50% of one of either p^2 or q^2 allele, (just be consistent) what happens?
There are quite a few mass starvations recorded from Eritrea and Ethiopia to Uganda and Bangladesh. But as I said there is what is known in statistics as a survivor bias. A google search easily finds this.
Reply | Report Abuse | Link to thishttp://us.oneworld.net/article/millions-face-starvation-bangladesh-famine http://www.actionaid.org/main.aspx?PageID=650
http://www.guardian.co.uk/society/2008/aug/11/aid.africa
http://www.who.int/nutgrowthdb/database/countries/en/index.html - This last is the WHO database on child malnutrition. Please note that most of the 250,000 measles deaths (as one instance) only occur because of malnutrition.
It might be useful to temper your arithmetical argument with a little observational evidence. The FACT is that the average number of children per mother is DECREASING, worldwide. Until your model can account for that rather salient fact, it's got some holes in it.
Reply | Report Abuse | Link to thisRe. mass starvations... yah, what I should have said is alleged EXTRA mass starvations. That people starve is not prima facie evidence that Erlich's population bomb (or its intellectual descendant) is exploding. If the number of people starving were INCREASING, it might be so... but the FACT is (the pesky thing) that the number of starvations is actually in free-fall. Consider that a growing problem among the word's poor is OBESITY! Not a bad problem to have, and a pretty good indicator that Erlich is full of it.
I believe only 2 countries in the world have a positive population growth curve at the moment. I believe with eductation GM crops and changes in technology we will survive, if not TB, Sars, Bird Flue and Malaria will be natures way of solving the problem. The predictions this guy makes are linear and based on todays technology, with solar power stations, world super electric grids are electric cars we will reduce the dependance on fossil fuels, so I see a bright futur. Note The population in China will start to crash after 2015, as one person will have to support 2 parents and 4 grand parents. Solar power, eductaion and reduced population is the only way to save space ship Earth.
Reply | Report Abuse | Link to thisjscroft - You need to reread what I posted until you actually comprehend it. The point you posted about number of children is central to the thesis. Pay better attention when you read.
Reply | Report Abuse | Link to thisit's pretty pointless to keep telling women what to do to save the planet if governments wont enact and enforce laws that enable them to safely DO so. women worldwide have no proprietorship over their OWN bodies, let alone paychecks. it's pretty vicious to yet again, lay the fate of the earth (literally) at the feet of ONE half of the population, when all too many cant even insist on a condom being used without dire consequences. and if accidental, unwanted pregnancy occurs? what a sad joke THAT is.
Reply | Report Abuse | Link to thisIn all honesty, Dr. Ehrlich's proposal for slowing population growth is more designed for Less Developed Countries. It is fact that in Less Developed Countries women that have higher levels of education lead to reduced fertility rates. Women that have at least secondary-level education or higher give birth to 1/3 or 1/2 as many children compared to women that have had no education at all. the reason for this is that educated women are better able to make decisions about their reproductive lives. An example of this trend: in 2005 women in Ethiopia that had no education had on average 6.1 children compared to women with education who had 2 children. This is obviously an extreme case, however there are many similar cases throughout the world that are similar to that of Ethiopia's.
Reply | Report Abuse | Link to thisEhrlich is correct--but the timing of human misery incex is variable. In 1950 2 billion people graced this earth--in just 60 years it has exploded tyo 7 billion. The quality of olife for this population can not be acurtely meaured but the quality of life for the human race will decline as the increase of population soars to 9 billion by 2050. The Chinese solution of one child families will become worldwide with in this time frame. Possibly more violent solutions will occur.
Reply | Report Abuse | Link to thisWhat is really needed is an immediate worldwide "one child" policy for all nations. Similar to China's policy, this will reduce the human population radically within 20 years to more sustainable levels for the planet.
Reply | Report Abuse | Link to thisAlong with the morality of killing off people, we have developed a hubris that regards the poor of the third world as people needing our help because they are too stupid/ignorant/reproductively rampant, to control their own destiny. How dare we try and hold the right to life because we have the benefit of living in a country with adequate developed resources and education. We only need to have the same atitude of the greatest men and realize we have no right to tell populations how to live/breed/die. It is their life. If they want our help, we should give it; but only on their terms not ours. The problem that third world countries have is not resources or potential, it is infrastructure. If we could help them with roads and ports and agricultural knowhow, we could probably help them more than giving them a bucket of rice. We musn't exchange need with judgement. They don't need us to judge them as inferior - this is a value statement anyway. What is inferior? How is it measured? We may not understand all of the stuff going on in the world but how dare we pontificate and believe we have the answers to the world's problems.
Reply | Report Abuse | Link to thisI think educating women is going to be more difficult than Ehrlich and Pringle suggest, especially in sub-Saharan Africa. Women are simply property that men own, they have no rights per se. Most women there don't want 10 children but the husband will abandon them if they don't produce. Just educating women will not work. You're going to have to start with the men.
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