Biodiversity Is Always a Goal, Right?

Apparently not. Consider this interesting passage from The Revenge of Gaia: Earth’s Climate Crisis and the Fate of Humanity, by James Lovelock:

Stable unchanging climates lasting for several thousand years tend to reduce diversity, but when the climate changes to either hotter or colder by a small amount the first response is an increase in biodiversity. This is because the new conditions give rare species a chance to flourish while the established ones have not had time to decline … [I]t is important to keep in mind that biodiversity and environmental quality are not simply proportional … So rich biodiversity is not necessarily something highly desirable and to be preserved at all costs.

This is a very different view of biodiversity than one gleans from most sources, and keep in mind that this is not the view of some nature-hater. Lovelock is the renowned British climate scientist who refers to himself as “a planetary physician,” bent on stopping humans from killing the Earth.

At the very least, the takeaway here is that the push and pull of evolution is endlessly complex — and, of course, endlessly fascinating.


"planetary physician" - Nice. Can I sign up please?


It is very curious that doomsayers often invoke the extinction of species as one of the serious effects of climate change, but no one ever talks about the creation of new species as a result of adaptation to new conditions. Darwin (Happy Birthday, Chuck!) was well-aware of the "economy of nature":

The extinction of old forms is the almost inevitable consequence of the production of new forms.

Jamie McAllister

I'm not sure Lovelock is that well renowned. I see him more as a self publicising fruit cake. It's not so long ago he suggested the mass release of CFCs to avert an ice age. Now he's on the global warming bandwagon. Listen to his pronouncements at your peril.

Bob Whiteman

So, what DOES indicate a quality ecosystem? Greater biodiversity is very useful to us right now because our environment is changing rapidly. The more species we have available to try to fill new ecological niches, the more likely there won't be major collapses of parts of our life support system. Greater biodiversity also means we have a wider variety of species to examine to discover new drugs. To put an economics spin on it, greater biodiversity means we have a wider variety of suppliers available to us. How uneasy would you feel if your business relied entirely on something available from only a single supplier?

Besides, ecology is inconceivably complex. To think that we know enough about our life support system to say "Oh it's okay, we can do without those species" is pure hubris.

Mate Varga

I think most people would agree with the bulk of Lovelock's arguent - exept for the very last sentence. That just does not make too much sense, and many people will get the wrong conclusion (e.g. we can just go on and kill species, because that's the way things work).
Biodiversity, under _natural conditions_, works pretty much the way it is described. And, for that matter, we do know that the climate is changing now - so we ought to have high biodiversity. If we reduce it artificially, we might get rid of those very few "rare species", that could easily repopulate the niches left open by vanishing breeds. (Who would have wanted to preserve those obscure, nocturnal, furry reptiles, when the mighty dinosaurs were roaming the Earth...?) And while it is true, because of the way evolution works, that nature will fill up in the end all the niches, there are issues with timing. If large ecosystems can't equilibrate themselves within reasonable time, they'll perish, and that could have large effects - like making food _really_ scarce for us.


Chris Dudley

Wow! Talk about quoting a source out of context to twist the meaning. Lovelock is saying that seeing an increase in biodiversity as a response to warming is not a good sign. Both places you have elided in your quote substantially changes the apparent meaning.

But it is also important to note that Lovelock is not using biodiversity in its usual sense either. He seems to think that a system with the same number of species is most diverse when all species have the same number of members. If there are some species that are rare, then the system is less diverse. This is very strange since ecosystems require some species to be more numerous and others less. Predators, for example, are less numerous than prey. Normally, biodiversity is considered against monocultures produced by human interference or the lack of biodiversity following a major extinction event: in other words, species count.

Another error seems to be a confusion of the manner of measuring biodiversity with what is being measured. We want to know about the biodiversity of an ecosystem. We put a box down and count species within that box. If we wait for an ice age and use the same box, we'll see a reduction in formal biodiversity as Lovelock thinks, but the correct thing to do is to realize that the ecosystem of interest has migrated and so we need to put down our box in its new place, not its old place.



Sorry but it's not climate change that's doing the most for eliminating species. It's human modification of habitat.

We're living in the Anthropocene, the old rules don't apply. Nature can't re-balance our actions.

Mark Williams

First of all, James Lovelock has very good reasons for espousing the view that we have already damaged the earth beyond repair, and that it will repair itself by ridding itself of us, its plague; I think he's right, but you don't have to resort to insult to say that you think he's wrong.
The comment that species will emerge from this is nonsense; evolution takes tens of thousands if not millions of years. The timescale we have for global warming is decades - a few generations at best, and not enough for migration, let alone evolution, to save any lines of species.
A mass extinction is inevitable, if you define, say, the loss of 10 per cent of identified species as a mass. It is happening now, all around us. Songbirds have declined in number (not species) by 50% in the last 40 years and a large number are probably not viable populations long-term.
Biodiversity matters to us on several levels. It should matter to us because we want to share this earth with an amazing variety of creatures. It should matter because there is so much beauty in nature. But it should also matter because many of those species may have a use for man which we have not yet discovered, especially in the plant kingdom. We may be watching our salvation slip away.
The plain fact is that there are too many human beings on this planet by a huge margin, and until something comes along to wipe out 25% of humanity, we are doomed to wallow and drown in an ever-deepening sess-pool of our own effluent.


Tom Rooney

The information given by Lovelock in the quote lacks a factual basis. There is no compelling published scientific literature demonstrating declines in diversity over thousands of years (presumably the number of species globally?--Lovelock lacks precision here). There is evidence that speciation (the evolution of new species) can increase during periods of climatic change over thousands of years, but there is also evidence that extinction rates are elevated during these periods.

I would put Lovelock into the camp of nature-hater (although he is a lover of the environment--the two are not the same). He would gladly poison marine biodiversity to stabilize the climate.


I agree with Chris Dudley's post. I don't think this premise holds water, or is taken out of context. There is no way species evolve or adapt at a faster rate on average than they die off on average. Possibly under certain conditions in some ecosystems this would be true. Maybe Lovelock is presenting that these conditions exists.

He is right about proportionality, and the notion that biodiversity may come at costs that are too high (for us), under these certain conditions. But let's not imply that global climate change is what causes biodiversity, because I can't imagine that's true, at least not in the shorter term.


Re Comment #6:

The notion of counting species is completely off-base: species classification, to paraphrase Charles Darwin, is an arbitrary, manually-curated process, not a well-defined systematic methodology. The genomes of two closely-linked varieties of the same species (say, 2 inbred lines of maize) have already been shown to be less similar than the DNA sequence of two species in different orders (say, humans and mice). Because species classification is such an inexact, laborious process, it's a lot easier to measure the extinction of existing species than to regard the appearance of new forms as species.

Darwin is more likely to be aligned with Lovelock's notion of an ecosystem's biodiversity: its ability to sustain highly divergent (read:rare) forms and to promote their production.


i think the tongue-in-cheek title confuses the functional argument with the ethical one- that is, the functional argument on biodiversity will analyze presumably on utilitarian grounds, whereas an animal rights activist would indeed argue that biodiversity is always an a priori ethical goal

Chad Bergeron

Darwin (Happy 200th Birthday!) understood this, and also other things about the process of evolution. For instance, evolution doesn't always lead towards increased complexity of organisms, it just tends that way.

The truth of Lovelock's point depends on how "biodiversity" is measured. Consider the sentence

"This is because the new conditions give rare species a chance to flourish while the established ones have not had time to decline."

According to Lovelock, this flourishing of rare species represents an increase in biodiversity. But no new species are being created in this scenario: the overall species count is constant. The only thing changing is the distribution of the number of individuals per species.

Many enviornmentalists have observed that stable ecosystems have several dominant species but many more minor species waiting to emerge if the environment changes. What ought to worry us now is that many of these minor "backup" species may be threatened with extinction, robbing us of a plan "B" in case of climate change or other environmental disaster.


I'm reaching back a bit to biology classes long ago taken, but isn't the fear of reducing biodiversity bigger than just that reduction's impact on us? I think that biodiversity insures that, in some catastrophic event, there is enough variance in life forms that some will survive and continue, insuring the continuance of life. Like having a forest with many types of trees and plants insures that when a conifer beetle comes through and kills all the pines, there are other trees and plants that maintain the habitat in a now-modified form. One fear is that there isn't enough variance in human life to insure our survival should such an event occur, but the larger planetary issue is that some life forms will continue on to make sure that "life goes on". But I suppose most people aren't really concerned whether there is life after people.

jonathan feldman

Is he talking about the enviornment or the economy?
(businesses = species)

Shirley Gregory

Sorry, Stephen: faulty logic at work here. There's nothing in Lovelock's comments against protecting biodiversity. At the same time, allowing biodiversity to decrease today won't do anything to curb climate change: climate change (and, yes, human interference with habitats) is causing biodiversity changes, not vice versa.

Chris Dudley

SP (#11),

I gave my comment in the context of reading the original source material for the quote given in the article. You may need to read the original as well to decide what Lovelock is saying about diversity. Googling a sentence from the quote will get you to an Amazon preview of Lovelock's book.

It may be difficult to count species for the purpose of determining biodiversity. Nevertheless, this is what is done. Measuring extinction can be a chore as well. Ivory-billed woodpecker extinct or not?

Lovelock is, in my opinion, discussing the increase in the occurrence of rare species, not the new evolution of species, in the passage from which the quote was drawn. This is why his use of the word biodiversity is unusual since normally those rare species would be included in a biodiversity measure and their relative frequency would not be important.

Joao Ramos

I don't understand the relation of the title with the Lovelock 's passage.

It states the impact of climate changes on biodiversity. The (doubtful) fact that an undesirable (by our current civilization) climate change leads to greater biodiversity says nothing about biodiversity as a goal, but as a consequence. The title makes it sound like there might be a reason to desire less biodiversity, but we can't obviously infere from that passage, even if we give it full credit, that less biodiversity could mean no climate change. Really faulty logic.

Norma Harrison

if they are resurrecting, we must help them by supporting organizations like the Ivory-billed Woodpecker Foundation (, dedicated to the continued search of the ivory-bill and other highly endangered - almost extinct species.