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Jeff Sachs on biodiversity
His new book Common Wealth devotes an entire chapter to this important topic. Sachs writes:
The main lesson of ecology is the interconnectedness of the various parts of an ecosystem and the dangers of abrupt, nonlinear, and even catastrophic changes caused by modest forcings...It is a basic finding that biological diversity increases the productivity and resilience of ecosystems. With more species filling more niches in a given location, a biodiverse ecosystem is better buffered against external shocks in is more adept at cycling nutrients, capturing solar radiation, utilizing water resources, and preventing the takeover of the system by single predators, weeds, or pathogens. In other words, preserving biodiversity helps to preserve all aspects of ecosystem functions. Removing one or more species from an ecosystem, for example, by selective harvesting of trees or fish or hunted animals, can lead to a cascade of ecological changes with large, adverse, and nonlinear effects on the functioning of the ecosystem.
Now, loyal MR readers may remember that I am genuinely uncertain how much we should worry about the loss of biodiversity. I do know the following:
1. Many smart people who know much more science than I do are very worried about the loss of biodiversity.
2. Given that the human population has ballooned for the foreseeable future, massive losses in biodiversity are inevitable. The question is how bad the marginal losses will be, if we do not adapt policy accordingly.
3. If I had to conduct a debate and argue that the marginal loss of biodiversity was going to be a tragedy for human beings (obviously, I can see the loss to animals, and yes I do count that for something), I would not do very well. Yes Yana's children won't eat tuna and then I would sputter something about carbon and nitrogen cycles.
So OK readers, help me out. I've read Sachs's passage and I don't think I disagree with any of the claims in it. But I still cannot articulate to a skeptic exactly what marginal disaster will come if we do not take drastic action to preserve biodiversity.
Please use the comments to set me straight. What exactly will go wrong? And do not compare seven billion humans to pristine nature. Compare seven billion humans with bad biodiversity policy to, say, five billion humans with a pretty good biodiversity policy. What exactly is the difference? What are these costs as a percentage of gdp?
Please be as specific as possible; I genuinely would like to learn more.
Posted by Tyler Cowen on April 6, 2008 at 05:36 AM in Science | Permalink
Comments
Would an analogy help? What would happen to the economy if we wiped several businesses, even a few whole industries? After a few months/years other companies would took their places, but in nature the time necessary for replacement is tied to evolution, so we're talking about at least thousands of generations to relevant mutations create new species, depending of the niches wiped we may be talking about millions of generations. Loss of biodiversity would entail in a ecology recession that would probably be much longer than our recorded history is.
Posted by: Daniel Yokomizo at Apr 6, 2008 6:10:53 AM
Economically oriented discussions of biodiversity often call to my mind the legal concept of depraved-heart murder.
Definition -
: a murder that is the result of an act which is dangerous to others and shows that the perpetrator has a depraved mind and no regard for human [or any?] life. Depraved-heart murder is usually considered second- or third-degree murder.
Pronunciation: di-'prAvd-'härt-
Posted by: Robert Hahl at Apr 6, 2008 6:32:38 AM
The deliberate destruction of sparrows under Mao Zedong's Great Leap Forward (1958 - 1962) was meant to eliminate a pest that ate grain seeds. Initially harvests improved, but so did the reproductive rate of the local locusts and other insects, which were now relieved of large numbers of their main predator. A famine that killed 38 million people followed.
The deliberate introduction of rabbits to Australia in 1859 has been identified as the largest single factor in the extinction of one eighth of Australia's native mammal species. The rabbits' effect on large swaths of the landscape has had direct consequences for agricultural production, since the rabbits destroy vegetation that prevents soil erosion, and regulates the water cycle.
Posted by: Matthew Wittman at Apr 6, 2008 6:45:30 AM
Over-simplification of our ecosystem, where species that we can benefit from are domesticated, whilst the others are wiped out, makes our food chain extremely un-resilient to disruption. An optimally efficient system, with no complexity, leeway or feed-forward is fine in stable, predictable times but cannot deal with fluctuations such as crops being wiped out by infections - witness the potato starvation of Ireland, as an example of what happens when you've not got enough legs to stand on.
Secondly, a key lesson of ecology is that the law of unforeseen circumstances is extremely relevant here. Our interventions in ecology in the past have on occasion produced shockingly unexpected, disastrous effects. Based on historical performance, humans are not capable of accurately and safely interfering with what has been a largely stable, complex system that currently provides us with a hospitable living environment. Just like the economy, big shifts, whether designed by an academic or unfortunate consequences of urbanisation etc, can have ramifications way beyond our predictive ability. The conservative/"right wing" ecologist would argue that we are better off trying to preserve what we have and recede our interference in our ecosystem, than try to shape it around ourselves (whether deliberately or by negative externalities of unchecked human proliferation)
Posted by: Philippe Bradley at Apr 6, 2008 7:11:02 AM
A lesser consideration is the heart aching beauty of untouched areas: not just tropical rainforests, but places such as high mountain ecosystems, desert ecosystems, and temperate rainforests (Pacific Northwest, Tasmania, New Zealand). Zoos and parks are wonderful for teaching, but they are artificially maintained, and the loss of a species or two probably won't change the overall impact.
The interconnectivity of biodiversity means that we're not losing a species here or there, but losing the entire system. Ecology teaches us that when something is disturbed, the ecosystem moves on, and that "recovery" to an original state is often not possible.
Its not just not eating tuna, it is a loss of something of great beauty that cannot be recovered.
Posted by: at Apr 6, 2008 7:28:46 AM
Ecosystem services such as degradation of pollutants, disposal of wastes, natural production of food, raw materials and oxygen, protection of shorelines, etc. have been conservatively estimated to exceed in value all human production. Given that reductions in biodiversity reduce ecosystem services, that's a large price to pay. I don't know how large.
Another key point is that loss of biodiversity eliminates our options for restoration of particularly productive ecosystems. As well as economic activities associated with charismatic megafauna such as hunting and tourism. 50 years ago, who would have thought whale-watching would have become a big tourist draw for New England?
And most importantly, biodiversity is the library of genetic information which we are on the brink of exploiting. Every species is the end result of a huge period of natural selection to solve problems that we're only beginning to guess at in ways we do not understand except in a few simple cases. Plant breeders (like me) rely on searching this library for solutions to disease and pest problems that have arisen in uncountable natural experiments. Not to mention other sorts of useful variation. Loss of biodiversity is very much like burning many sections of the library, but preserving the best-sellers.
Libertarians haven't changed much on these issues in the past 20 years.
Posted by: Mike Huben at Apr 6, 2008 7:36:56 AM
Another very important point re biodiversity is tha we're still learning plenty from nature. New medicines are inspired by chemicals produced by animals, new materials come from research into insect exoskeletons, new developments in robotics come from studying ant colonies.
A loss of biodiversity results in a reduced field of information from which to draw inspiration and discovery.
It would be sort of like if physicists never looked up. Sure, they'd still have plenty of things to study, and plenty of advancements left to make, but there'd be all sorts of things they'd miss out on, because they never got the chance to see them.
In my opinion, this is even worse for humanity than the loss of environmental stability associated with reduced biodiversity. Creative thought is quite possibly the most valuable commodity I can imagine, and the fewer the sources of inspiration available, the less creative thought that will occur.
Posted by: Michael Woods at Apr 6, 2008 7:39:58 AM
Best reason I can come up with : There is no substitute to it.
Unlike oil that we can figure out how to replace, either as energy source or as material. Unlike mineral resources which can always be recycled.
Once you lose biodiversity, it's forever (economically speaking). So its market price should be astronomically high. Why isn't it? Because each specie has a huge potential value (medical, for reasearch, for its own sake, for who knows what else), but since we know so little about most of them, the market cannot put a price on it.
In a thousand years, when future generations have the technology to study, classify and exploit to its full the treasure chest of Earth's biodiversity, they will swear at us for the mass extinction we caused and didn't stop.
Posted by: Nicolas at Apr 6, 2008 8:39:34 AM
Most of the millions of species on the earth are limited to one or a few places and are closely related to other nearby species. Losing them is like losing small businesses in a recession. Perhaps one of them will be the next Hewlett-Packard, but otherwise their loss will have little influence on the world.
In a dynamic economic with lots of mobility, new businesses arise quickly to take the place of extinct ones. Obviously, this doesn't happen with species. The big question is how much this matters. Is it like the loss of languages, where the loss is mainly aesthetic (and it is notable how often political ecology arguments are aesthetic, e.g., "the heart aching beauty of untouched areas")?
Or are we losing irreplacable and tremendously valuable sources of medicines, materials fabrication techniques, etc? Are we "burning many sections of the library, but preserving the best-sellers"? No one really knows.
Posted by: Roger Sweeny at Apr 6, 2008 8:41:46 AM
These seem very weak arguments so far, and not really focused along the lines that Tyler asked for. Let me try.
Biodiversity is worth pursuing because the marginal cost is close to zero, when implemented as part of a broader program of modernization.
The #1 threat to biodiversity is agriculture. Better fertilizer, farming practices, irrigation, genetics, storage, transport, and so on will allow more food on less land. So will ending subsidies for biofuels and inefficient domestic crops (e.g. sugar beets). All of these policies are needed to improve agricultural productivity, and they have the side benefit of freeing up land for biodiversity protection.
The #2 threat to biodiversity is pollution. Experience over the past century has demonstrated that societies do not like pollution, and as soon as they can afford it they start doing something about it. So, maximizing GDP growth to shorten the transition time to prosperity will not only make people wealthier and healthier, it will allow them to afford a cleaner environment, which promotes biodiversity.
The #3 threat to biodiversity (and this is WAY down the list) is residential development. It's been argued on this forum that ending housing subsidies would be economically beneficial, and it would have some benefits for biodiversity as well.
See? Biodiversity can happen as an adjunct to policies that directly benefit humans.
Still feel like you need to implement a policy that is biodiversity specific? Fine. Put a tax on organic food to reflect the extra land that it requires. There. Don't you feel better?
Posted by: Bob Knaus at Apr 6, 2008 8:50:21 AM
Michael Woods, I am not so convinced of the 'inspired by nature' argument for biodiversity, for two reasons.
First, many if not most claims of 'Natura artis magistra' are more poetic than realistic. People just like to see a comparison with nature, and claiming your material is inspired by insects is a sure way to get into popular magazines. Medicins inspired by natural substances are rarer than people think.
Second, while I am sure there is a lot to learn from nature, I am not sure how much biodiversity we would need for that. If we do the worst we can to the world, there will still be more than enough ants left to learn our robotics and exoskeletons from.
Posted by: greatzamfir at Apr 6, 2008 8:52:28 AM
Not thinking marginally, but just to keep our options open, do we have any idea how much about biology we don't know and need to learn? Like what if we wiped out cats, and no longer had Toxoplasma, and it turned out to add important capabilities to our minds? Or what if they find the non-carbon-based life on earth they've been looking for recently (discarding the assumptions that would have made us miss it). We just have no idea what we're wiping out.
Posted by: Noumenon at Apr 6, 2008 8:55:28 AM
What's the difference between loss of biodiversity due to human behavior and loss of biodiversity due to nature? Millions of species have gone extinct for millions of years, and yet life goes on.
Posted by: Hei Lun Chan at Apr 6, 2008 9:09:07 AM
Once you lose biodiversity, it's forever (economically speaking). So its market price should be astronomically high. ... Because each specie has a huge potential value (medical, for reasearch, for its own sake, for who knows what else) ...
Yes, and no. Each species certainly has a value "for research." A future doctoral candidate can't study something that is no longer there. But that is true of anything that people change. No one can study what the ecological succession would have been on the place where my apartment now stands. If there are no white supremacists in a hundred years, no one will be able to interview them. That there will be a loss does not answer the question of what we should do to prevent it, of which things are worth how much to preserve.
Of course, one can give a blanket answer, "everything matters and should be preserved 'for its own sake'." Everything has a near infinite value. That is bracingly conservative, but most of us aren't conservatives (or Paretians).
Does each species have a huge potential medical value? Certainly not. Some probably do. Most probably don't. To try to save them all will certainly prevent some loss. Will it be worth the cost? To say it will is a statement of faith--and hope.
Posted by: Roger Sweeny at Apr 6, 2008 9:23:50 AM
This is key:
Removing one or more species from an ecosystem, for example, by selective harvesting of trees or fish or hunted animals, can lead to a cascade of ecological changes with large, adverse, and nonlinear effects on the functioning of the ecosystem.
When we think in terms of marginal changes we are implicitly assuming smooth functions, more or less predictable systems, etc. But we don't know that there are not discontinuities or sudden dramatic changes in velocity.
In other words, we don't know "exactly what will go wrong." Neither did Bear Stearns.
Posted by: Bernard Yomtov at Apr 6, 2008 9:56:46 AM
While it seems right not to "compare seven billion humans to pristine nature," why do you ask to compare "seven billion humans with bad biodiversity policy to, say, five billion humans with a pretty good biodiversity policy."
Why "five" and not "seven", if you want to be careful to "compare like with like", as, I think, Milton Friedman used to say?
Posted by: philippe coquoz at Apr 6, 2008 10:22:15 AM
The chief difficulty of pricing (the loss of) biodiversity marginally would appear to be complexity. You just don't know with what likelihood any given cocktail of species loss will set off a cataclysmic chain of events (much less which specific cataclysmic chain of events). It might be reasonable to start by assuming these probabilities are monotonically increasing in diversity loss, but getting more specific than that probably takes a Ph.D. in biology and a dose of divine intervention.
Posted by: Sean at Apr 6, 2008 10:42:14 AM
Martin Weitzman's QJE papers suggest a workable framework for pricing species of high marginal value. Since we cannot save them all, seems best to prioritize species and save as many as we can. I doubt we'll come close to the optimal MR=MC point so might as well start saving them now.
The biodiversity for prospecting literature does not suggest a high value (JPE papers forget the authors).
As for a John Krutilla-type option value, that's awfully hard to measure, where do you even start? Even bounds are unlikely to be agreed-upon.
Posted by: Jack at Apr 6, 2008 10:47:18 AM
I'm not so sure biodiversity cannot be created artificially, re: Craig Venter. But I agree it's best to start having a "better safe than sorry" approach to biodiversity.
Posted by: karl strom at Apr 6, 2008 10:49:40 AM
Tyler asks "What exactly will go wrong?"
That framing makes it impossible to give a specific answer. No one knows what exactly will go wrong. Folks who study ecosystems can point to examples where bad things have happened - crashes of systems where many species that are quite interdependent all go down. It's very hard to pinpoint a strategy for saving biodiversity to product maximum resilience and benefit for humans. It's easier to point to particular areas and say that resilience is dropping, but even then it's not so easy to figure out the cost of trying to reverse the trend, and the benefit of making the effort.
If we limit things purely to threats to humanity, I think that a lack or resilience in farm crops is a big one to worry about, since so much of our food stock comes from just a few grains (whereas in the past the number of grain plants that were eaten was much much higher). But what is the percent chance of widespread grain failure? And what is an allowable risk factor? (Should we use the Dick Cheney rule - one percent chance is enough to trigger action?)
Posted by: Curt at Apr 6, 2008 10:56:13 AM
One thing we should do regardless is create a databank to hold the genomes of every species. The economic/technical (i.e., non-aesthetic) value of every species other than our own is in its DNA, since only humans create and transmit learning/culture across generations.
As our knowledge grows, we will be able to exploit those genomes as we now do with the organisms themselves, finding their value for food production, energy production, medicines, etc.
We are on the verge of creating wholly synthesized life forms even today. These abilities will only grow.
Diverse ecosystems have many benefits as listed by the other posters, but that isn't the same thing as preserving individual species. In that sense, the analogy to losing a small business is a good one.
Posted by: Larry at Apr 6, 2008 11:02:03 AM
If I may change a few words in the Sachs quote...
for example, by selective [regulations] of [industries] can lead to a cascade of changes with large, adverse, and nonlinear effects on the functioning of the [economy].
For examples, see Smoot-Hawley, Europe's ban on GM imports and its effect on Africa, or on a smaller scale Tyler's cars versus foot patrols post.
There's all sorts of unanticipated secondary effects when a regulation is imposed on the economy (which similarly reduces socio-economic diversity) and it can similarly have cascade effects.
So for those arguing the precautionary principle for bio-diversity, will you also extend that argument to preserving socio-economic diversity?
I suspect not, because most of the commentors (cept for Bob Knaus) appear to be approaching this with an implicit prioritization of bio-diversity over socio-economic diversity. I find this confusing because by virtue of it having a more direct mechanism, the degree of socio-economic diversity should have a greater impact on humanity than the degree of bio-diversity.
Posted by: Jody at Apr 6, 2008 11:24:18 AM
Volatility is bad.
I think the argument for bad impacts is toughest to make persuasive because it hinges on the cousin of the Law of Unintended Consequences -- the Law of Unpredictable Changes. These changes could, in total, be really really really bad, yet since they are a set of consequences that are tough to pin down, they sound...airy -- without substance.
The feeling of "not knowing" doesn't change a lot of minds, unless perhaps they are particularly able to cross-apply concepts such as the Sharpe Ratio to...our collective ecological portfolio.
Posted by: infopractical at Apr 6, 2008 11:43:13 AM
1. Many smart people who know much more science than I do are very worried about the loss of biodiversity.
I don't know how to say this without sounding catty, so I'll just charge ahead. People who know a lot of science can also have a lot of emotional baggage.
Many people in the biological sciences are trying to understand how nature works, and humans are constantly disturbing their work, even destroying a good deal of their potential research base.
Imagine you and your friends are deeply concerned with understanding the game of basketball. But recently, people have begun mass disruptions of games, running onto the field at all sorts of times. Even if you manage to catch a game without disruption, you know tactics have changed to deal with that possibility. You will be extremely annoyed by the disrupters and will probably come up with all sorts of reasons why they are menaces to civilization--and you will believe them.
Or consider the controversy over deaccessions by museums, where museums sell off "surplus" art. Many art lovers just don't want to hear arguments about how this strengthens the museum's economic health, how it makes it possible to buy other more important works, etc. Art is good, and to get rid of it is bad.
Many who study nature have a semi-sacred attitude toward it. My Wilderness Society calendar for April has a beautiful picture of eroded sandstone in a prairie and the caption, "To see clearly is poetry, prophecy, and religion--all in one. John Ruskin" Destroying the sacred must have terrible consequences at some point in the future.
Posted by: Roger Sweeny at Apr 6, 2008 11:53:20 AM
Some definitions of biodiversity from a google search. When determining good vs. bad diversity policies, it makes sense to establish what biodiversity is. A definition that limits it to number of species will probably miss many of the values of biodiversity to humanity.
For instance genetic diversity within a species may promote survival of the species under changing environmental conditions (e.g. Peppered moth- genes in the population that resulted in black coloration promoted survival under polluted conditions, genes that resulted in light coloration promoted survival under conditions of better air quality). This form of diversity could be very important when dealing with crop disease.
Species diversity within a system may assist with retaining nutrients, prevention of sedimentation, maintenance of desired game or aesthetically-pleasing wildlife species, reduce risk of disease for humans (not as a source of medicines, but increased hosts for vectors-Google lyme disease/biodiversity), maintenance of desired plants species, etc.
Diversity of habitat types within an area generally promotes species diversity and at global scale different habitat type provide different services to humans (grasslands-grazing, forests-timber), partly because they contain different species adapted to those conditions.
Also, contributing to confusion is that biodiversity can be measured at different scales- local, regional, and global; and some of that may not scale up in terms of analyses.
I'm sure I've probably missed some of the variations of biodiversity. But, for all these forms of diversity some measure of economic value can be derived.
Googled Definitions of biodiversity (and there are several more variations of the same...)
Number and variety of living organisms; includes genetic diversity, species diversity, and ecological diversity.
biology.usgs.gov/s+t/noframe/z999.htm
The variety of life in all forms, levels and combinations. The term biodiversity includes genetic diversity, species diversity, and ecosystem diversity.[i]
www.csbsju.edu/environmentalstudies/curriculum/greenbuildingplan/Green%20Building%20Plan%20p12.htm
The number and variety of different organisms in the ecological complexes in which they naturally occur. Organisms are organized at many levels, ranging from complete ecosystems to the biochemical structures that are the molecular basis of heredity. ...
www.nsc.org/EHC/glossary.htm
The number of different species in a given habitat
prairieu.umn.edu/
The variety and abundance of species, their genetic composition, and the natural communities, ecosystems, and landscapes in which they occur.
www.governor.wa.gov/gsro/glossary/default.asp
Posted by: longleaf at Apr 6, 2008 11:58:27 AM
There have been five major extinction events in the past billion years. Now we're in the middle of the sixth, caused by us. At the rate we're going, somewhere between 50% and 95% of species on Earth will be gone by 2100.
If some future paleontologist 100 million years from now digs up the fossil record, this damage will still be dramatically evident. There will be no trace of anything else we care about, good or bad. The state of our economy is ephemeral fluff. Our empires rise, fall, and disappear. But this...this is lasting.
What's more, we have no idea how common life is in the universe. For all we know, it takes a hundred billion galaxies worth of stars, it takes that many rolls of the dice, before this incredibly rare and precious thing called life comes into being. Until we find other life in the universe, perhaps we should assume that life is indeed a rare jewel in the universe, something that is our responsibility to guard as well as we can.
But you want something practical, centered around human benefit. Fine. Many biologists have serious doubts that humans won't be one of the species to go extinct. How's that for practicality? Non-biologists have no concept of our dependence on the natural ecosystem.
Here's one hint: the bees are dying off, and nobody knows why. Clearly something's out of balance. Maybe it's GMOs, maybe it's pesticides, maybe it's loss of habitat. Probably it's a combination of factors. But what we do know is, 30% of our food supply depends on the pollination services provided by bees.
Bats and songbirds are disappearing as well. They eat bugs. Now we can enjoy a lot of extra mosquitos in the summer, along with extra helpings of the various diseases they spread.
Our civilization is a mere 10,000 years old. We have never experienced the kinds of planetary changes that are beginning to occur. We have no idea whether we can actually weather these changes. The system is so complex, so interrelated, that we really have no idea what will happen.
Posted by: jeo at Apr 6, 2008 11:58:32 AM
Read a book by a real economist: the Ultimate Resource 2 by Julien Simon
Posted by: karl at Apr 6, 2008 12:02:14 PM
Is it not ironical that so many of the progressive thinkers who get exercised about the importance of biodiversity, justified at least partly by the belief that decentralized and complex networks are richer and more robust, simultaneously favor centralizing power in government, presumably leaving society poorer and less robust?
Posted by: Alan Watson at Apr 6, 2008 12:35:16 PM
To Roger Sweeney,
I eat plants and animals, breathe oxygen, am sheltered by a house partially built with wood products, and probably would have died without discovery of penicillin, so I feel pretty dependent on services provided by species other than humans.
But in defense of the idea that biodiversity of non-cultivated species offers more than reduced headaches to scientists studying nature: wheat eaters have benefited from existence of non-cultivated wild species used to create disease resistance in wheat.
Posted by: longleaf at Apr 6, 2008 12:55:57 PM
You need a sense of alternatives. There are one billion cows on this planet. Most of those cows aren't living anywhere where they are indigenous. Most of the resources we dedicate to cows we could put toward people instead.
So, really, the question is: What's more important, one billion people or one billion cows? Mankind's taste for dead cow flesh carries a tremendous cost if you care anything about having more people on the planet. (And, yes, I think life without eating cows is just as enjoyable as life with eating cows.)
The cow should be a rare animal, like the zebra and the hippo. Let's stop breeding them for dairy and slaughter, and you will have plenty of space for more humans *and* more bio-diversity.
Posted by: Macneil at Apr 6, 2008 1:05:59 PM
Mass extinction is simply a mathematical process. Species go extinct all the time, it's just a question of how far the ripple-effect extends with each specie. Roll the dice and eventually you get a mass-event:snake eyes. Artificially increasing the extinction rate is the same as rolling the dice faster and faster. The odds on rolling snake eyes doesn't change, but the timing on when you will does.
Posted by: p.a. at Apr 6, 2008 1:14:21 PM
"But I still cannot articulate to a skeptic exactly what marginal disaster will come if we do not take drastic action to preserve biodiversity."
Tyler, have you considered at all the possibility that the issue is not what marginal disaster will come, but that *we don't know* what disaster, if any, will come? In other words, we have examples of past events where humans eliminated/tinkered with one species in an ecosystem and found negative results to other species. We also have examples where we found species *that we were not looking for* that proved to be very valuable. We put these together and come to the conclusion that we do not know much about most of the species, nor do we know how they are linked together, nor even how valuable any of them might be for human use. And until we figure that out some more, please don't break anything.
"Please use the comments to set me straight. What exactly will go wrong? ... What are these costs as a percentage of gdp?"
The whole point of stopping further degradation of ecosystems is that in many cases we do not yet even know what we are losing. It may be nothing. It may be a whole lot. But we *do not know*. You can go ahead and slap a number on what we do know, but the number is a quantification of our ignorance and not our knowledge.
Posted by: jared at Apr 6, 2008 1:22:23 PM
jeo: Only one species of bee is dying off. The other ~20,000 are fine. We only even care because it's the one most used for pollination. So this isn't even an issue of biodiversity--people actually are trying to save the European honey bee because it has large economic value. In this case the interests of people are aligned with the interests of the bee. Also, similar drops in the honeybee population have occurred in the past, and were noted even in the 19th century. So likely not even caused by any recent human activities (pesticides, GMO).
Posted by: Andy at Apr 6, 2008 1:24:09 PM
Recall that "Many smart people who know much more science than I do" thought that Stalin was a fine fellow.
Posted by: dearieme at Apr 6, 2008 3:00:12 PM
Some commentators are confusing biodiversity with species loss. They are not the same. We have a (lack of) biodiversity problem when every farmer in Kansas plants the same variety of high-yield corn, and then we discover that a corn borer finds it particularly tasty. We have a species problem when the passenger pigeon goes extinct. In "Skeptical Environmentalist", Lomborg shows that the latter is a made-up problem: species are not going extinct every minute as scare headlines suggest. The biodiversity problem, however, is real. One might also worry about non-bio diversity, e.g. if all tractors burn gasoline or all computers run Windows.
Posted by: Robert Ayers at Apr 6, 2008 4:03:41 PM
What Jared said. (a) tails are fat (b) people tend systematically to underestimate risks of these kinds (c) future generations are not present to advocate in these matters. If they were, would they chastise us for not turning rainforests into savannas at an even faster pace than we are now doing?
Everyone should read Julian Simon, because he demonstrates what you have to believe, what you have to be *sure* of, to genuinely not be worried about this kind of question.
Posted by: Colin Danby at Apr 6, 2008 4:14:42 PM
longleaf,
I think you have misinterpreted me. Every human on this planet is completely "dependent on services provided by species other than humans." Without them we would all die.
But that fact says nothing about what the harm would be from reducing biodiversity, which was, after all, Tyler's question.
Without food, people die. Many Americans go on diets and reduce their intake of food. That doesn't mean they are starving to death.
Having said that, I think we can all agree that planting the entire Mississippi valley in the same variety of corn or wheat would indeed be a high risk strategy. Prudence would require that we "buy insurance" by preserving other varieties, or develop the tools to genetically modify the grains we have when the necessity arises.
Posted by: Roger Sweeny at Apr 6, 2008 4:38:33 PM
The weakness of the argument, something really bad could happen if this continues, is, why couldn't something really bad happen if this doesn't continue? If we have no way of knowing which species-deaths could, for example, trigger the collapse of a major agricultural staple, we also have no way of knowing which species, by their continued existence, threaten the same. The loss of biodiversity is scary for all kinds of reasons, but if the scariest part is what we don't know, then we don't know enough to manage biodiversity in any sane sense.
Posted by: Cyrus at Apr 6, 2008 5:52:16 PM
"Is it not ironical that so many of the progressive thinkers who get exercised about the importance of biodiversity, justified at least partly by the belief that decentralized and complex networks are richer and more robust, simultaneously favor centralizing power in government, presumably leaving society poorer and less robust?"
What if a person wanted to actively use government to make society more decentralized and more robust? For example, what if somebody wanted to use government tax credits and subsidies to encourage widespread decentralized electricity production, in order to have a grid that was more robust to outages?
What if, in order to combat the threat of violent Islamists who want to use intimidation and violence to shut down speech, somebody wanted the government to provide an open ISP of last resort?
What if we wanted to try to use government to send signals that would enable anybody around the world to draw unfiltered internet access, to destroy the ability of certain other centralized governments to censor information?
All of these are active government interventions in pursuit of more decentralization.
Posted by: Keith at Apr 6, 2008 6:37:00 PM
Reductio: eu- or dys- topia? Future earth species roster = humans, cats, dogs, cows.
Posted by: ted at Apr 6, 2008 7:45:05 PM
"Given that the human population has ballooned for the foreseeable future, massive losses in biodiversity are inevitable."
It is inevitable if the state keeps on subsidizing unsustainable lifestyles. There is nothing inevitable about 6 (or 10, or 20) billion people using the land the way we do – on its face, it would seem that since energy is expensive, and clearing and maintaing structures on land is expensive, one would seek to minimize the amount of energy and land that one consumes. And we do do that to some extent – not everyone lives in a 6000 sq. ft. house with a two acre yard, and we sort of pay attention to how much gasoline we used – but we really are estranged from these costs by state intervention.
Our meat comes cheap because our crops come cheap because we pay farmers to plant them, our suburbs come cheap because our roads come cheap, and our imports from China come cheap because the state has borne a lot of the cost of ensuring that goods can get from point A to point B without hassle. Economists rand and rave about how this must be an unalloyed good – cheap transportation costs – and that the state has a proper role there, but isn't it possible to have transportation (as any good) be too cheap? And when do you know when you've gotten there?
There's nothing magical about the number 10 billion that necessitates a certain drop in biodiversity. It all depends on how far we stray from the free market. But you can be damn sure that without addressing serious issues with the "American dream" and transportation planning (somewhere to start: do we need it at all?), any artificial limits won't even come close to dealing with it. And even now, the world has already adopted the model (which the Americans in turn adopted from Hitler and the Soviets), but it's possible that change in the US might spur change elsewhere, as well.
Posted by: Stephen at Apr 6, 2008 8:22:34 PM
A few points:
1: Much like how we don't know what things are worth until people start trading them, and the bidding process kicks in, I don't think we can know how much damage we are doing to biodiversity and/or how much that damage damages *us* without actually seeing what happens when we deliberately destroy biodiversity, such as clearing out areas of nature for development or whatever. Without pinning down actual cause-and-effect relationships we are making shots in the dark, and potentially very damaging shots in the dark.
2: Apart from examples of deliberate interference with biodiversity (birds in China, rabbits in Australia, etc.) can anybody point to substantial examples of real harm to biodiversity (and humans) from normal development? IOW when harm to biodiversity was a side effect of some economic growth? Merely clearing forests and wetlands isn't what I'm talking about, as deer and ducks just go somewhere else (or are already found elsewhere).
3: If we pin down a real cause-and-effect between development and real harm to biodiversity, then it seems to me a simple tax on development is in order. The actual amount can be related to the size of the development in acreage (on land that was previously undeveloped) and the rate can rise or fall based on some target in development growth. The target could be linked to population growth in the area. i.e. a tax that runs between 2% and 10% based on how quickly or how slowly the population is growing. A rise in population means real demand for more development, whereas a decline in population means less real demand for more development and the use of existing developed land is more desirable.
Posted by: Jacob Oost at Apr 6, 2008 8:39:44 PM
Cyrus it's reasonable to try the argument out on the other side. But as Robert Ayers says, it's not a question of adding or subtracting individual species, but of moving from a more biodiverse to a less biodiverse state of the world.
The point perhaps is *not* to "manage." While Alan Watson's gibe is a bit empty because of his failure to name anyone, there's a plausible point if you turn it over: people who understand decentralization and resilience and problems of knowledge *should* appreciate the pitfalls of approaching the natural world as a management problem!
Posted by: Colin Danby at Apr 6, 2008 8:52:22 PM
Several points:
1) I see a net cost to me from adding a few billion people to the planet. We have the same land surface, miles of beach, grazing lands for livestock, etc. But a few billion more people to want to use this stuff.
2) Declining biodiversity isn't just a problem due to lowered stability of ecosystems. Declining biodiversity is a sign that we are using an increasing fraction of all biomass for our own purposes. The higher the percentage of biomass we use the less room we have for handling, say, a drought or an extended period of low sunspot activity.
3) We can't model the planet's ecosystems accurately. When we were intervening in a small fraction of the total biomass that didn't matter much. But we are now eating into and harnessing such a large fraction of total biomass that the limits of our knowledge put us at some unknown but possibly quite large risk.
4) People who argue we can solve our problems by eating less meat are missing the point: Most people like meat. Given the buying power most people in the world who don't each much meat now will buy a lot more of it.
5) Economic growth in Asia and the rest of the world is increasing buying power for meat and other food and for wood for houses and other biomass products. Even without adding a few billion people to the world's population we are set to use a much larger fraction of the biomass than we are already using now.
6) We are very actively developing technologies that will let us use biomass in more ways. That is what cellulosic technology for making ethanol amounts to. Take that would that is useful for structures and also make it useful for powering cars. This is happening against the backdrop of $2500 cars going on sale in India and China's economy charging ahead at 10+% per year.
Between economic growth, technological advances, population growth, and declining reserves of fossil fuels I think the demand for biomass materials will rise very rapidly. Bye bye other species.
Posted by: Randall Parker at Apr 6, 2008 9:00:06 PM
Where I said: Take that would that is useful for structures
I meant to say: Take that wood that is useful for structures
Posted by: Randall Parker at Apr 6, 2008 9:02:59 PM
Jacob Oost,
Economic development in China is giving the Chinese growing buying power that is causing them to buy imported animal products on a scale large enough to wipe out species in south east Asia, Indonesia, and other places. Many Chinese believe in special powers from claws, pancreases, and other body parts of assorted big cats and other animals. Bad news for those animals now that China is industrializing.
Posted by: Randall Parker at Apr 6, 2008 9:08:48 PM
Randall, my suggestions are for a free market, not a planned economy like China's. The lack of information from a lack of free market trading leads to inefficiencies like that.
And I hope that the Chinese are buying these animals from those countries rather than just taking them for themselves, otherwise where are the high prices to keep these items rationed out?
Well, without going into too much I think what you are talking about are some economic problems that stem from a lack of free markets, not caused by them.
Posted by: Jacob Oost at Apr 6, 2008 9:38:26 PM
Jacob Oost, Chinese buying power is increasing as a result of less planned economy. It is the free market element of China's economy that is making it possible.
No, China's effect on animal species is not the result of a lack of free market. If China was still under a Mao style economy then the Chinese would have less money to buy animal parts from abroad.
Posted by: Randall Parker at Apr 6, 2008 10:09:59 PM
(I realize that I am conflating biodiversity and species loss, so I hope knowledgable readers will be forgiving of my intellectual sloppiness.) Biodiversity has benefits that are difficult to value. This is an unremarkable statement that has been floating around the culture for decades. Just think of the plot of Star Trek IV, in which Earth in the 23rd century was placed in mortal peril because all the whales had been wiped out. If future man had known that the whales were that important, we would of course have ensured their survival, but we came to that realization too late.
Let’s assume that there are thousands of species on the verge of extinction. A handful will be extremely valuable (e.g., leading to the cure for a deadly plague), yet we don’t know in advance which species will be the lifesavers.
The current enumeration of the world’s species is analogous to holding a portfolio of extremely out-of-the-money call options. The portfolio diminishes in value over time as options expire, i.e., as species disappear. We can renew the call options by keeping species alive, but the costs are considerable, and the benefits are not only difficult to measure, but both the time of realization and the probability of realization are unknown. (It’s safe to say, however, that the probability of this concept being accepted by environmentalists is zero!)
Posted by: Steve Yuen at Apr 6, 2008 11:44:13 PM
@Randall Parker
Point #4: What if we (the U.S.) stopped subsidizing corn (which in turn is used to produce cheap meat)? What if we taxed meat (or non-grass fed meat anyway)? Read the first two parts of Michael Pollan's "The Omnivore's Dilemma" for some interesting stuff.
Posted by: David at Apr 7, 2008 12:32:47 AM
It's much worse than sloppiness, Steve, it's imposing assumptions that assume the problem away. The key word in the original passage is *system*. If you equate that to a situation in which you are keeping n species alive in separate little cages, you assume away the system!
Posted by: Colin Danby at Apr 7, 2008 1:38:33 AM
David, The price of corn has quadrupled and people are still eating lots of meat.
Politicians aren't going to tax meat. They want to get elected.
What if we supplied lots of birth control drugs and devices to those countries with high fertility rates? Why not address the overpopulation problem instead of telling people what to eat?
Posted by: Randall Parker at Apr 7, 2008 1:57:03 AM
The single biggest mistake in considering human effects on the environment is the assumption that we are somehow 'outside nature' or separate from the ecology.
We are not. We are a species of primate, albeit a highly developed one. We are ultimately subject to the same ecological pressures that every other species is. Whenever the population of one species becomes unsustainably out of balance with the environment a correction takes place. To take the most obvious examples, a food shortage may occur, a virulent strain of virus, parasite or predator may take advantage of the large numbers and increased density of hosts/prey, all resulting in deaths of large numbers and the correction of the population back to a more sustainable level.
Posted by: Yasmin at Apr 7, 2008 4:02:13 AM
Because we'll miss them when they're gone.
Posted by: Steve Sailer at Apr 7, 2008 6:54:19 AM
Perhaps this point has been made above, but the problem to me is the definition of "marginal" destruction of biodiversity.
An ecosystem is interlinked, and wiping out a key species (marginal decrease of one) could do severe damage to the system. It is hard to do a cost-benefit analysis when the cost side is so complex. Destroying one spider species that parasites on ants perhaps has little cost, but removing the ants is likely to be expensive.
When the economic problem is complex, we usually argue for non-intervention.
Posted by: christian gormsen at Apr 7, 2008 8:06:42 AM
I'd recommend EO Wilson's, "The Future of Life" as a very interesting read on the impact of bad bio-diversity on humanity.
http://www.amazon.com/Future-Life-Edward-O-Wilson/dp/0679450785
Posted by: shariq at Apr 7, 2008 8:23:26 AM
Seems to me that Sachs' statement is a lot of eco-religioius mumbo jumbo. It may hold on small islands with unique species and ecosystems, but doesn't seem to hold for the rest of the planet. Human development can change a particular ecosystem and reduce biodiversity in a particular area, but it doesnt necessary reduce overall biodiversity. Sometimes human activities increase biodiversity. Clear cutting often results in greater rather than less biodiversity when a forest with little biodiversity is replaced with meadows with far more diversity. However, people often seem upset over that type of increase in biodiversity.
Also, what makes anybody think that government policies are likely to increase biodiversity. Every attempt to save the African elephant through government fiat has been a disastrous failure. Allowing people to benefit economically from the existence of the African elephant has actually helped the elephant.
I think bad government policy is far more likely to hurt biodiversity than simple increases in human population.
Posted by: Paul at Apr 7, 2008 9:34:01 AM
But I still cannot articulate to a skeptic exactly what marginal disaster will come if we do not take drastic action to preserve biodiversity.
To demonstrate the limits of economic argument in this sphere, let us consider a slightly more drastic case. Can anyone articulate what marginal disaster would be caused by the total extinction of the human species, say as an unintended side effect of action foregone (or taken!) to preserve biodiversity? What is the economic value of lives never lived, and in what freely-traded market is it set?
The closest I can come to an economic answer is that investors who hold long positions in, for instance, thirty-year bonds have foregone current consumption for future returns, and will therefore be economically damaged by not being around to collect. But for every lender who loses, there is a borrower who gains, so the net present value of continued human survival appears to be a wash in the bond markets. Similar analysis applies to equities and other assets: the present value of there being a human future is not obviously positive. It would be very surprising if the market value of the survival of other species accurately reflected our moral intuitions, when the valuation of our own survival does not.
Posted by: Joshua W. Burton at Apr 7, 2008 10:48:05 AM
Friends
a. Biodiversity has been reduced by us, is being reduced by us; and the question we face is how far we should slow down that reduction, and if so where?
b. Biodiversity supports the human (and other) species as a hammock supports a relaxing human. We know that the increasing strain we put on that net is causing fibres to break at a good number of points, but we have little overall idea of which points and how far the fibres affected support us. When disaster comes it may be marginal or it may be catastrophic (and some of the fibre failures will just make the hammock feel more comfortable).
c. Minimising maximum regret suggests that it is well worth investing in finding out rapidly what we can usefully do. (The best place I know to get into that is at http://royalsociety.org/displaypagedoc.asp?id=29026 ). A sceptic should therefore be asked if he or she sees a better decision criterion to apply right now? Thereafter, we should be able to do cost benefit studies.
Posted by: David Heigham at Apr 7, 2008 11:31:47 AM
I think that there are couple arguments to be made about why we should be concerned about the loss of biodiversity.
1) Humans are animals. We are intertwined with the ecosystem in a way that it doesn't make sense to speak of us as "separate". For example, there are 500 to 100,000 species of bacteria live in the human body -- without which you would die. (see: http://en.wikipedia.org/wiki/Human_flora for more information.) The appendix is a bacterial incubator to keep these things alive. (This is one of the reasons why taking antibiotics knocks you out.) So the question is, given that we exist within the ecosystem and vica-versa, what would happen if we totaled the ecosystem? At this point I think the question is unanswerable, but it potentially could be very bad. Maybe nothing, or maybe it would be a "cost" we could bear. At any rate, right now, it's unknown.
2) I think the losing biodiversity will be viewed roughly the same way that we view the burning of the library of Alexandria. Both represent a loss of irreplaceable knowledge. People mention Craig Ventor and synthetic biology above: they don't mention that the bulk of that research is trying to catalog preexisting genomes. We aren't creating genes; we are remixing them from the natural sources. Once we get the code then we can print it, but its going to be a long, long time before 3 million years of evolution on even the gene level, let alone the species level.
What will be the cost of the loss of biodiversity? What was the loss of the library? I have no idea how to price lost knowledge, but I think that genes are more of a scarce resource than ideas.
3) Also, the current situation is unprecedented. While there have been 5 mass extinctions over the last 3.5 billion years, the current Holocene extinction is the most rapid. An estimated 50% of species in 100 years is tremendously fast.
I know that the question was looking for a quantitate analysis, but the point is that it's unknown and potentially very, very bad. It could also be just another wipe-out-the-dinosaurs routine event, and if we are able to isolate the impact upon primates then it doesn't matter economically. But our current scientific understanding isn't enough to ensure that, and we're destroying the exact resource we'd need to exploit to engineer our own system.
Posted by: Will Schenk at Apr 7, 2008 3:38:17 PM
Will Schenk writes:
1) Humans are animals.
Again, from a narrow economic perspective, so what? If we all died, whose pocketbook would feel it the next day? What market sets the revealed preference of the human race for survival over extinction?
These are silly questions, of course. But for the same reason they are silly, Homo economicus is the wrong guy to ask about the value of biodiversity. Mr. Cowen's question is badly framed, and that's really about all that can be said about it.
Posted by: Joshua W. Burton at Apr 7, 2008 3:58:00 PM
We will find a way in labratories to create better life than what we have now (whatever you think "better" to be). In that sense, there is no living creature worth saving at some grand expense. Biodiversity is the kind of crap you would lobby for, too, if you were on the shit end of the food chain. "Who knows? Maybe I cure your species' cancer in a million years..."
Posted by: mpkomara at Apr 7, 2008 4:27:13 PM
Wait a minute.
The deliberate introduction of rabbits to Australia in 1859 has been identified as the largest single factor in the extinction of one eighth of Australia's native mammal species. The rabbits' effect on large swaths of the landscape has had direct consequences for agricultural production, since the rabbits destroy vegetation that prevents soil erosion, and regulates the water cycle.
Posted by: Matthew Wittman at Apr 6, 2008 6:45:30 AM
So it would seem that if Australia is ok then we have nothing to fear.
Posted by: Dan at Apr 7, 2008 4:29:01 PM
The claim that is propagated in much of this discussion is basically: "We don't know how much a given species is worth so let's invest a lot in saving them all". But ignorance to the point of being unable to even offer a range of possible damages if a species is lost cannot be a basis for an investment policy.
However, there are two factual claims that are being made:
1.) The net value of any species is at least non-negative from a human point of view, hence it makes
sense to invest in saving any of them.
I don't think the antecedent of this is true. Yersinia pestis and Loxodonta africana are highly problematic species from a human point of view. Their genome may still have some value and the latter is certainly beautiful, but does that really compensate for human illness and destroyed crops?
2.) Ecosystems are complex entities, delicate houses of cards, and the removal of even one of the species may cause the system to collapse to the point of a drastic reduction in the human food supply.
This is a standard claim made by ecologists and there are mathematical models that are indeed very sensitive to parameter change, but has it ever been backed up by facts? Is there any historical example of one species disappearing and taking the local human food supply with them? Given the rate at which species are dying out right now, there should be at least some prominent examples, but I'm not aware of such a case.
What I am aware of are cases where humans tried to implement an artificial ecosystem where they were the only predators. Various attempts at monoculture are examples as are the experiments with sparrow extermination by the Chinese in the fifties (which, by the way, isn't an example of a famine caused by the extinction of one species. A lot of things were going wrong during the Great Leap Forward, and the famine probably would have happened with or without the sparrows).
These artificial ecosystems often fail because it is not possible to keep competitors to human predation out for very long. While this is unfortunate for the humans involved, it points to the resilience of ecosystems rather than to their weakness.
Posted by: Dagmar Alpen at Apr 7, 2008 5:44:44 PM
The marginal disaster would be system collapse. Obviously, biodiversity represents a system, not discrete species. The acceleration of extinction is what should be of concern. If we reach a point at which the acceleration accelerates beyond a capacity to recover or adapt, we in big trouble.
Someone aksed, "What's the difference between loss of biodiversity due to human behavior and loss of biodiversity due to nature? Millions of species have gone extinct for millions of years, and yet life goes on."
Bad analogy. In the mega-extinctions, enormous periods of time were involved in adaptation and evolution to a new equilibrium. The concern today is acceleration causing the rapid arrival at a point of system collapse.
Posted by: Brian at Apr 7, 2008 5:47:27 PM
Here is a very specific and real example of how a lack of biodiversity can be very bad:
1. Potatoes are not native to Ireland.
2. At first, only a few varieties of potatoes were imported into Ireland.
3. These varieties became very popular with the Irish and the Irish came to depend on the Potato.
4. Most of the varieties in Ireland became infected with a virus.
5. There were no (or few strains) resilient to the virus due to the lack of diversity available in Ireland.
6. Nearly one million Irish died.
This is only one example of how the lack of biodiversity can cause us problems. This is akin to not having a diverse portfolio.
Another important part of biodiversity is like Donald Rumsfeld famously said: "unknown unknowns"
For example, The Amazon is home to many pharmaceuticul drugs already and yet we've barely tapped the surface of the plants we know there. Who knows? There may be a cure for some cancer hidden in there....
Posted by: RobertV at Apr 7, 2008 7:18:40 PM
1. Ecologic systems are complex so it seems reasonable to pay attention to biodiversity and try and reduce human societies negative impacts on it.
2. For the economists the crucial issue is determining which policies are likely to help species preservation and which would harm it.
3. Many biodiversity advocates have a complete lack of understanding of the very real problem of unintended consequences of government action.
They don't realize poorly thought out government actions can create negative externalities that are worse then the problem they were trying to solve.
Because government is so big and has so many resources it can cause environmental damage on a scale private action never could.
This problem goes go all the way back to provisions in the homestead act. Other examples are the western water projects, the massive pollution at DOE facilities, and the destruction of wetlands by direct government action.
Economists can play a crucial role in biodiversity preservation by
1. Assessing proposed government policy for unintended consequences / negative externalities.
2. Help structure preservation policies so that resource stakeholders are economically rewarded as a result of biodiversity preservation.
Posted by: TJIT at Apr 7, 2008 10:30:16 PM
My First Posting:
Concerns over biodiversity deserves an institutional response. There is a great diversity of art works in the world, much of it unusual. Yet, we do not worry that "art" is declining or that programs are needed to "preserve" artistic diversity.
And, of course, the reason is that art works are integrated into the system of voluntary exchange. A person valuing some form of art can (and often will) devote resources to acquiring and protecting that art "varietal."
Biodiversity is a "problem" because the collectivist domination of policy for the last century has blocked the integration of many plant and anaimal life into the system of voluntary exchange. Lacking property rights, these items are left out in the cold -- "protected" at best by Chattering Class policies.
Anyone who gardens or has pets will recognize the proliferation of species now available in catalogs. Whether for gardens, pets, or commercialization, we see no diminished listings in our seed catalogs. Commercial varieties, of course, are always a small fraction of the total, but the rapid expansion of "Heritage" and "Heirloom" species (varietals that were once cultivated but that have proven competitive) argues that people will move quickly to "preserve biodiversity" when the institutional framework allows it. A world of voluntary exchange does not need an EPA or an ESA. Pigouvian taxes or quotas - the variety of tastes among the population preserves variety itself.
Note that there are only some 200 or so governments on this planet, while there (according to E.O.Wilson) some 10 million or so species meriting some degree of protection. Many of these governments have not done well at protecting their citizenry. How likely is it that they will do better with ferns and bugs? Yet, there are now 7 billion or so people on this planet, most having to varying degrees a collector/aesthetic sense. If these people were empowered to own the flora and fauna then that protective value would do much to concern the hysteria over biodiversity. The fact that few in the environmental movement feel any inclination to promote ecological privatization or ecological adoption suggests that their values are more political, less environmental, than generally recognized.
And, since this is the Marginal Revolution blog site, note that we don't need to do this everywhere for everything at once. Simply place any species at risk up for "ecological adoption." Australia concerned with threat posed to some of their rarer pines arranged to make populations (seedlings) available to collectors, improving the sustainability of that species. Why not do this generally?
Posted by: Fred Smith at Apr 8, 2008 9:41:34 AM
I'm going to make a good-faith effort to respond to Tyler's question. "Biodiversity" as it's usually interpreted seems to suggest that it's important not to destroy any species. While there might be a moral argument for such a policy (i.e., I can't create a whooping crane, so why do I have the right to destroy them?) it's hard to make an economic argument for biodiversity, defined broadly like this.
Instead, it makes more sense to argue that humans depend on certain kinds of wild habitat, and there are immediate costs associated with its disruption. Most notably, estuaries prevent coastal flooding and forests prevent erosion and absorb carbon dioxide. In China, for instance, the estimated economic benefit of flood mitigation from wetlands in Jilin province was $5700 / hm^2 / yr. link . I don't know how to extrapolate those numbers globally, but often wetlands are worth more as flood protection than as vulnerable developed land.
Posted by: sarah at Apr 8, 2008 10:43:24 AM
What will go wrong?
Increased risk. Is a 50% chance of $1000 the same as a guaranteed $500? We are taught to believe it is, but really, it isn't. How do we quantify the difference?
Posted by: Margaret at Apr 9, 2008 3:02:18 AM
biodiversity: the variety of life in all its forms, levels, and combinations. Includes ecosystem diversity, species diversity, and genetic diversity (IUCN, UNEP, & WWF)
It seems to me that the difficulty with addressing biodiversity is that we do not understand ecological systems well enough to predict the effect of specific events, which makes it impossible to establish the risk. I am not an economist, but I am a biologist (not to be confused with an ecologist). So, I am going to restrict my comments to addressing biological points that have been made in this discussion.
from Sachs: "With more species filling more niches in a given location, a biodiverse ecosystem is better buffered against external shocks...Removing one or more species from an ecosystem...can lead to a cascade of ecological changes with large, adverse, and nonlinear effects on the functioning of the ecosystem."
Self-contradictory, to a degree, Sachs argues that ecosystems are simultaneously robust and fragile. The large, non-linear effects would only occur if a specific "hub" species were removed, assuming that ecosystems are organized as scale-free networks, which is debatable, but implied by Sachs' commentary.
Daniel wrote: "so we're talking about at least thousands of generations to relevant mutations create new species, depending of the niches wiped we may be talking about millions of generations"
Actually, niches are filled very rapidly. Think "Nature abhors a vacuum" here. If the species occupying a niches is wiped out, another species, that would have been otherwise less fit than the original, will fill it. This doesn't address the impact this would have on humans.
Nicolas wrote: "Once you lose biodiversity, it's forever (economically speaking)"
The biodiversity that we have now will be lost (i.e., the specific species and genetic diversity that we have right now). New biodiversity will arise to replace it. For example, mammalian diversity did most of its expansion very shortly after the K-T extinction (dinosaurs) Of course, the time scale for this effect is long in human terms.
karl strom wrote: "i'm not so sure biodiversity cannot be created artificially, re: Craig Venter."
This could generate new species diversity, not genetic diversity. The synthetic life people are all working with genes discovered in "natural" organisms. It also remains to be seen how viable these processes are. Currently, we are limited to replacing the genomes of existing organisms. It is also important to remember that individuals like Craig Venter, while being excellent scientists, are also great promoters of their own work. Finally, they are working on bacteria. Most biodiversity concerns involve plants and animals. Microbial diversity underpins all of our ecosystems, and we do not have a good handle human activity is doing on that front.
It is unclear what the effect of loss of species diversity will be on humans. The loss of genetic diversity among domesticated species and their antecedents can be quite important economically. Advances in quantitative genetics have demonstrated that valuable genetic variants can be found in crop lines that are themselves, as a whole organism, not a productive strain. Reduced diversity also increases the risk posed by disease (how much? we don't know).
My personal experience is that an obsessive focus on biodiversity as an end unto itself is more of a carryover of the Scala Naturae (Great Chain of Being) philosophy that motivated many naturalists in past centuries. This is based on Christian creationist thinking, which is somewhat ironic.
Posted by: JTW at Apr 9, 2008 2:18:49 PM
I'm with the commenters who point out that it's difficult to talk about marginal cost with a function that is likely to be highly discontinuous.
On the other hand, as Bob Knaus pointed out, many of the potential efforts to preserve biodiversity have a relatively low marginal cost.
I see it like insurance. In a limited sense, the cost of insurance will never be worth the benefit - in the aggregate, the value of premiums earned will always exceed claims paid. But there's two reasons insurance makes sense anyway. One is that it is more efficient to set aside small (and known) amounts every month than a large (and unknown) amount once in a lifetime. The other issue is that the externalities associated with the large loss are much greater than with the smaller premium expenses. So there's a net benefit all around even though the insurance companies always profit.
Insurance makes sense when you have events with a low probability but a high cost. That's the case with ecological collapse. I think it is difficult to justify a huge expense to maintain some (more or less arbitrary) biodiversity target. But the marginal cost function for loss of biodiversity, whatever it is, is highly discontinuous, and at some point gets very large. And the marginal cost of many preservation efforts is relatively low. So if we structure the programs right, we can in effect get a lot of insurance for a relatively low premium.
Of course, that doesn't really quantify anything, so there's more work to be done.
Posted by: JBL at Apr 10, 2008 6:23:31 PM
I have no time to read all the existing comments, but I feel obliged to leave my own.
To me biodiversity has a huge value, maybe because my childhood was in a biologically rich environment.
If I tried to be objective, I would refer to the long history of biodiversity - it has taken about 3-4 billion years to get there, and the destroyed parts do not come back quickly, although they would come faster than in 3-4 billion years (maybe in 10 million years). Now how to translate this to a monetary value, I don't know.
People may be biophilic (see E. O. Wilson's book on this). Nature has been our environment for a long time, and those who have not experienced it may not know what they have missed.
Of course there are all the points about hidden possibilities (e.g., drugs), hidden dangers (collapse), productivity vs. richness, etc., but my point is that to some people biodiversity has a huge intrinsic value.
Counterpoints:
(1) If people grow up in an artificial environment, they may not miss or value biodiversity. So we could happily destroy it without causing any harm to anybody. (You can extend this argument to favor even direr conditions.)
(2) In a sense, species are of less value than higher-order taxa, because higher-order taxa have taken longer to develop, and genetically species within, say, a genus, are almost identical. If we want to destroy species, it is best to diversify the effort evenly over as many higher-order taxa as possible.
(3) Yes, it would be hard to decide between destroying species and destroying people, and even me would probably choose to save the people. So it may be too late to save diversity, given that we need to make compromises. Maybe we should then wonder how we did get here, and could we somehow do better next time (to prevent this kind of hard choices).
Posted by: Anon at Apr 11, 2008 3:29:57 AM
