Biodiversity: the top-level planetary boundary?

A two-day meeting organised by the Smith School here at Oxford University left me with the creeping impression that although it receives dramatically less attention, biodiversity may well qualify as a more important planetary boundary even than climate change itself. Moreover, it is a staggeringly complicated issue, and is not amenable to many of the technical fixes that might be used to address other boundaries like freshwater, land use and nitrogen.

Just about everything humans do affects biodiversity negatively. This should of course be obvious from first principles: the main objective of farming, for example, is to simplify ecosystems so that their productivity supports one species (ours) only, whilst urban areas are planned as human-centred habitats only. The converse of this is that where humans disappear, such as in the North-South Korea demilitarised area, or the Chernobyl Exclusion Zone, biodiversity rebounds strongly and does better pretty much than anywhere else.

Scientifically-speaking, any biodiversity good news is patchy when compared to the relentless decline in both the abundance and number of other species that share this planet with us. (See Butchart et al, Science 2010 for instance.) At the Smith School conference, slides shown by Simon Stuart (a co-author on the Science paper) showed that whilst the rate of decline in bird species was flat in recent decades, amphibians have seen an accelerated decline, whilst corals have seen losses which are little short of catastrophic.

All this underlines for me the conclusion that we should not be asking biodiversity to make trade-offs in order to deal with climate change. Extinction, after all, is forever, whilst glaciers may one day regrow and sea levels will fall again. Admittedly it will take thousands of years for the human pertubation to the carbon cycle to stabilise in the Earth system, but hundreds of millions of years potentially for evolution to restore pre-Anthropocene mass extinction levels of biodiversity. For me, perhaps the biggest reason to get to grips with global warming early is because it otherwise threatens to outstrip the adaptation capacity of natural species – as is already the case with coral reefs in the warming oceans.

There are some areas where synergies can be realised, for example with REDD + (Reducing Emissions from Deforestation and forest Degradation) in the UNFCCC negotiations: some environmental groups have been very sceptical or even outright opposed to REDD in the past because of the use of markets, but I think this position is counter-productive. Done right, REDD offers the chance to protect the forests and the climate at the same time.

This was a point missed by Bill McKibben in his recent comparison between the Amazon and Canada’s tar sands. McKibben posed the question: ‘If Brazil has to guard its rainforest, why does Canada/US get to burn its tar sands?’ The answer should be obvious: because the Amazon rainforest contains fully a quarter of terrestrial biodiversity, whilst the tar sands just contain tar (although the process of extraction is very damaging to large areas of boreal forest). So if you care about biodiversity, protecting forests is more important than switching off power stations as a climate mitigation option – and therefore worth paying for. (And it is in the financing that equity issues can be addressed properly.)

Just how to pay for forest protection, and for biodiversity generally, was one of the hottest topics at the Smith School conference. There were no easy answers provided. Whilst TEEB has undoubtedly laid some valuable groundwork, there remain many more questions than answers. Biodiversity trends, unlike carbon emissions, cannot be easily measured, quantified and traded. Therefore, in market economics terms, it is much more challenging to price in the externality of biodiversity destruction that likely supports a substantial proportion of global corporate profits.

Even so, I have little doubt that attaching a meaningful price to biodiversity is necessary if conservation is to become the global imperative that it needs to be. Something with no price stays off the balance sheet and therefore has no value in the harsh capitalist world we live in. Monetarising wildlife will not always be appropriate or necessary (or even ethical) but it is surely one of the tools we must use if the relentless decline in other species is to be slowed and eventually arrested altogether.


  1. David Bailey

    “some environmental groups have been very sceptical or even outright opposed to REDD in the past because of the use of markets”

    You can see why – because markets just operate for profit, exploiting whatever opportunity is fed to them. The carbon market is full of scams, and biofuel has been grown on land obtained by cutting down rainforest!

    Some of us ‘deniers’ are actually quite green – we just want Greenpeace to get back to real issues – and we don’t like the worship of ‘markets’. Here is a guy who left the Green movement over climate change.

    Yes Mark – biodiversity is a real green issue, unlike ‘climate change’ (it used to be called global warming until someone decided a vaguer phrase might be easier to sell). The habitats for animals are dwindling because of overpopulation. Unfortunately nobody seems to like to use that word, but it is at the root of a lot of our problems.

  2. Linus

    Dear Mark,

    You say that “biodiversity may well qualify as a more important planetary boundary even than climate change itself”. In what way do you suggest that biodiversity is a “planetary boundary”? A planetary boundary, in my understanding, is an aggregate level beyond which the earth system is at risk of sudden, dramatic and unpredictable change; a tipping point that must not be crossed if we want to avoid run-away planetary disaster. There is to my knowledge no evidence that the global level of biodiversity, especially when defined as the number of species, is approaching any tipping point; in fact, I doubt that aggregate global numbers of species has any meaningful relationship with human welfare in a non-spiritual way. If sea levels rise high enough for most Pacific islands to sink, we would lose a terrible amount of “biodiversity” but apart from the obvious effect on people living on these islands, this would scarcely be noticed elsewhere or indeed by the “earth system”. Most actual benefits of biodiversity and the ecosystems to which it is related are local and thus local losses of biodiversity are not necessarily felt at the planetary level. For the earth system to work we basically need a lot of photosynthesis and some other processes that come with ecosystems but there is, as far as I know, no reason to think that the earth system could not cope with significantly lower levels of global biodiversity, as it has done many times in the geological past.

    This brings me to your lament of the fact that it would take “hundreds of millions of years potentially for evolution to restore pre-Anthropocene mass extinction levels of biodiversity”. Why is this a problem? Who says that the level of biodiversity we had a few thousand years ago was the “right” level? We know that biodiversity is basically the result of a pretty random process of evolution, with no implied optimal level or indeed higher meaning whatsoever. Any such meaning comes from us, rather than some universal imperative to protect biodiversity – what we might want to do though is to bequeath a level of biodiversity that we think would be spiritually satisfying for future generations, but that is a matter of a democratic process where some people might have other, and equally valid, priorities.

    If we just got the prices right, we will save biodiversity. This has become somewhat of a mantra over the past decade or two. But what if “getting the prices right” does not save (all) biodiversity? What if human welfare is maximised by accepting losses of biodiversity in the many trade-offs that we face as the veritable gardeners of the planet? This is what’s happened many times before, when Europeans cleared the continent of forests to establish agriculture, or when colonisers did the same to American forests over the past few centuries. If the premise of getting prices right is that they are high enough to outweigh other alternative uses of land, or other priorities, then we must question the objectivity of the exercise of “getting the prices right”.

    Best regards,


    1. J Bowers

      “Who says that the level of biodiversity we had a few thousand years ago was the “right” level?”

      Neolithic farmers? Hellooooo civilisation.

    2. Mark Lynas (Post author)


      Perhaps the most useful contribution I can make towards answering your points is simply to copy and paste the biodiversity section of the original Rockstrom et al, 2009 Nature paper, as it does address (albeit briefly) some of your challenges:

      Rate of biodiversity loss

      Species extinction is a natural process, and would occur without human actions. However, biodiversity loss in the Anthropocene has accelerated massively. Species are becoming extinct at a rate that has not been seen since the last global mass-extinction event.

      The fossil record shows that the background extinction rate for marine life is 0.1–1 extinctions per million species per year; for mammals it is 0.2–0.5 extinctions per million species per year16. Today, the rate of extinction of species is estimated to be 100 to 1,000 times more than what could be considered natural. As with climate change, human activities are the main cause of the acceleration. Changes in land use exert the most significant effect. These changes include the conversion of natural ecosystems into agriculture or into urban areas; changes in frequency, duration or magnitude of wildfires and similar disturbances; and the introduction of new species into land and freshwater environments. The speed of climate change will become a more important driver of change in biodiversity this century, leading to an accelerating rate of species loss. Up to 30% of all mammal, bird and amphibian species will be threatened with extinction this century.

      Biodiversity loss occurs at the local to regional level, but it can have pervasive effects on how the Earth system functions, and it interacts with several other planetary boundaries. For example, loss of biodiversity can increase the vulnerability of terrestrial and aquatic ecosystems to changes in climate and ocean acidity, thus reducing the safe boundary levels of these processes. There is growing understanding of the importance of functional biodiversity in preventing ecosystems from tipping into undesired states when they are disturbed. This means that apparent redundancy is required to maintain an ecosystem’s resilience. Ecosystems that depend on a few or single species for critical functions are vulnerable to disturbances, such as disease, and at a greater risk of tipping into undesired states.

      From an Earth-system perspective, setting a boundary for biodiversity is difficult. Although it is now accepted that a rich mix of species underpins the resilience of ecosystems, little is known quantitatively about how much and what kinds of biodiversity can be lost before this resilience is eroded. This is particularly true at the scale of Earth as a whole, or for major subsystems such as the Borneo rainforests or the Amazon Basin. Ideally, a planetary boundary should capture the role of biodiversity in regulating the resilience of systems on Earth. Because science cannot yet provide such information at an aggregate level, we propose extinction rate as an alternative (but weaker) indicator. As a result, our suggested planetary boundary for biodiversity of ten times the background rates of extinction is only a very preliminary estimate. More research is required to pin down this boundary with greater certainty. However, we can say with some confidence that Earth cannot sustain the current rate of loss without significant erosion of ecosystem resilience.

  3. MarkB

    Stuck in the same rut. So I guess this means that global warming really isn’t ‘destroying the planet,’ is it?

    But then you do want greens to ‘make the trade-off’ on nuclear power, don’t you? And how long will it take before that nuclear waste is harmless?

    Please write an entry” My Priorities,’ in which you layout, in order, just what it is you care about most. Maybe then we can start having an intelligent discussion.

  4. John Millar

    Surely climate change is one of, if not the most, important driver of species richness and biodiversity decline. WE can use the often misused term biodiversity and wildlife conservation concerns to introduce people, especially children, to the concept and dire consequences of climate change.

  5. Gary Bowden

    Once you get past the order-of-magnitude matter (some problems are big, others less so), putting emphasis on one problem over another is pretty silly. Problems with planetary boundary implications are, by their very nature, big complex problems. It’s certainly legitimate to say biodiversity has received less attention over the past decade or so than climate change, but that doesn’t make it more important or fundamental. Indeed, if I had to make a case for ‘THE big issue’, I’d go with the uncertainty resulting from the myriad ways that the multiple planetary boundary problems might interact with one another (captured in Charles Perrow’s concept of a normal or system accident) rather than picking one or the other of the specific boundary concerns.

  6. Googol

    Linus has put his finger on a crucial issue. Local declines in biodiversity can be beneficial to humans, and are rarely catastrophic, except for a few who find their livelihoods threatened or vanished. Biodiversity has declined faster and faster at a global scale for decades, if not centuries, and all we have to show for it is a hugely improved standard of living for some of us, and many more billions of people on the planet. Some of those billions are worse off than their parents were, but not usually as a consequence of biodiversity loss. Causality is the other way round; increased human pressure on the environment has been paid for by the loss of biodiversity. Impoverishment is a consequence of locally diminishing kilos of carbohydrates per head, not diminishing biodiversity.

    As a generalisation, biodiversity loss has been good for us. If it continues to be good for us remains to be seen, but there is no obvious bottom to this pit. Should humans manage to garden every square metre of the planet, it will be bad for biodiversity, but humans might still survive.

    On purely utilitarian and anthropocentric grounds, biodiversity loss may not be anything to concern ourselves about. For this reason, I am highly sceptical of the idea of putting values on the priceless. The utilitarian, value-based argument seems to be rotten at the base.

  7. NikFromNYC

    Sea level is one of the best measures of AGW claims, since we have century long tide gauge records that are truly global and there is much less decade-by-decade noise in a highly inertial and self-leveling state. A simple average of tide gauges over 150 years shows utterly no trend change whatsoever:

    Those who scuttled the Atomic Age are not the ones I want to be in control of anything ever again, certainly not environmental policy!

    “Cheap Nuclear Power Could Lead to Civilization’s End” – Paul Ehrlich, 1972.

    The LA Times featured cold fusion in ’89 before its debunking. Greens were aghast!
    “It’s like giving a machine gun to an idiot child.” – Paul Ehrlich (mentor of John Cook of the SkepticalScience blog, author of “Climate Change Denial”)
    “Clean-burning, non-polluting, hydrogen-using bulldozers still could knock down trees or build housing developments on farmland.” – Paul Ciotti (LA Times)
    “It gives some people the false hope that there are no limits to growth and no environmental price to be paid by having unlimited sources of energy.” – Jeremy Rifkin (NY Times)
    “Many people assume that cheaper, more abundant energy will mean that mankind is better off, but there is no evidence for that.” – Laura Nader (sister of Ralph)

    These people, leaders of the Green movement, do not *want* clean and abundant energy. They hate and distrust humanity itself.This usually stems from self-loathing and envy along with envy avoidance for self and country.

    1. J Bowers


      2000 Years of Sea Level

      Another hockey stick.

    2. NikFromNYC

      You linked to a site currently registered to the PR firm that was behind both the junk science silicone breast implant scare that bankrupted Dow Corning and the junk science autism/vaccine scare, a site which moderates out any opposing comments which they lack of mocking soundbite as a reply to, and then no additional comments by that author are allowed in that thread. This presents the illusion that skeptical voices have silenced themselves, whereas actually they have been censored.

      In true PR fashion Michael Mann described as:

      “The idea is that we working climate scientists should have a place where we can mount a rapid response to supposedly ‘bombshell’ papers that are doing the rounds….”

      And that opposing views would not be allowed. Blogger Tilo Reber expresses this effect succinctly:

      “The whole purpose of the procedure is to give the illusion that the subject has been fairly and completely dealt with and that the pro AGW side has won – once again. From that point, any future arguments of similar issues by skeptics will simply be marked as, “discredited – see such and such a thread”. The entire RC web site is full of victories that are won, not by science or logic, but rather by censorship. Of course the average reader of RC doesn’t know this. He never sees the objections by skeptics that cannot be answered.”
      Environmental Media Services is a division of Fenton Communications.

      The paper referenced is co-authored by Michael “Hockey Stick” Mann, whose first hockey stick was shown to be based on “an artifact of bad mathematics” (Richard Muller of the new Berkley Earth Surface Temperature Project). Mann was also co-author of the recent Nature cover story study that also used “artifacts of bad mathematics” to present a false warming-all-over map of Antarctica, a study rapidly debunked in peer reviewed form, by O’Donnell, which was delayed for months since another co-author, Steig, was secretly assigned as a reviewer of the debunking paper for which he first forced a change which he later, before being outed as the reviewer involved, used to criticize the debunking paper (!). Steig actively pretended he had not been involved, early on, feigning that he needed a copy of the latest draft at one point.

      Here is Dr. Muller expounding upon not trusting Hockey Stick team papers any more:

      “”So that’s what they did. And what is the result in my mind? Quite frankly as a scientist? I now have a list of people whose papers I wont read any more. You are not allowed to do this in science. I get infuriated with collegues of mine who say well you know, it’s a human field, you make mistakes. And then I show them this and they say, uh, no…that’s not acceptable.”

  8. Blair

    I have to agree with the folks who suggest that that the global fight against CAGW cannot be allowed to dominate the conversation. I would argue that habitat protection is a necessary activity if we wish to maintain a healthy ecosystem.

    What I find interesting is that habitat preservation seems to be one area where all sides should be able to meet because no matter what side of the CAGW debate you may sit it has a net benefit. For the true believers the protection of habitat provides a buffering capacity that allows endangered ecosystems to adapt to change. For skeptics it provides a means to protect the environment irrespective of CO2 concentrations.

    Ultimately as the human population has continued its presumably logistic growth towards some ultimate peak the result has been a squeezing out of the ecosystems necessary to maintain a human presence on planet earth. Regardless of how you feel about global warming/climate change/etc… you should want a planet that is fit for human habitation and that means leaving room for non-humans to thrive and survive.

  9. Barry Woods

    totally of topic, I see that George Monbiot is supporting nuclear again in the Guardian. Also in the Guardian….

    How many years have sceptics been saying that the last decade tempuratures were flat.

    To be met with it’s the x,y,zth warmest on record – you denier..

    Well we have some good news in a Guardain article some NEW research says that the decade 1998 to 2008 the temperatures were indeed flat…. so good news…

    Yet, the bad news is, using computer models (again) the explanation is that because china has doubled its coal use, all that sulphur dioxide that has gone into the air has ‘masked’ the global warming.. other explanations, solar,e in the computer models don’t fit..

    at what point do people just start saying b***s**t, stop playing with computer models!!

    Guardian: Sulphur from Chinese power stations ‘masking’ climate change (my caps)

    Research reveals decade of global warming from China’s coal power stations has partly been offset by ‘cooling’ effect of sulphur pollution

    The huge increase in coal-fired power stations in China has masked the impact of global warming in the last decade because of the cooling effect of their sulphur emissions, new research has revealed. But scientists warn that rapid warming is likely to resume when the short-lived sulphur pollution – which also causes acid rain – is cleaned up and the full heating effect of long-lived carbon dioxide is felt.

    The last decade was the hottest on record and the 10 warmest years have all occurred since 1998. But within that period, global surface temperatures BUT DID NOT SHOW A RISING TREND, leading some to question whether climate change had stopped. The new study shows that while greenhouse gas emissions continued to rise, their warming effect on the climate was offset by the cooling produced by the rise in sulphur pollution. This combined with the sun entering a less intense part of its 11-year cycle and the peaking of the El Niño climate warming phenomenon.


    I wonder if any apologies will be forthcoming, to sceptics, who said the decade has not shown a rising trend, of, course the argument is now, it was warming, but it was masked by sulphur.

    No apologies for the abuse given out though for pointing the real observed data vs failed GCM predictions a plateau

    Now they have a semi plausible explanation, I doubt if there will be any blushes forthcoming.

  10. J Bowers

    “I wonder if any apologies will be forthcoming, to sceptics, who said the decade has not shown a rising trend, ”

    No apologies necessary, because the not-so-sceptics were using cherry picked data from one specific dataset while ignoring three others.

    Otherwise, if, as you say, this is based on new analysis, could you please tell us how these “sceptics” got their hands on this analysis before it had even been made? The public can’t even see the actual paper yet. I take it these “sceptics” do remote viewing?

    From the Guardian article:

    “Prof Robert Kaufman, at Boston University and who led the study, said: “If anything the paper suggests that reductions in carbon emissions will be more important as China installs scrubbers [on its coal-fired power stations], which reduce sulphur emissions. This, and solar insolation increasing as part of the normal solar cycle, [will mean] temperature is likely to increase faster.””

    So, will these “sceptics” who keep calling the likes of me a CAGW alarmist and religious zealot in on a fraud, apologise to me when the scrubbers have the desired effect on sulphur, but a highly undesirable effect via the CO2 molecule’s infrared absorption properties?

  11. Eli Rabett

    ooo Eli loves Calvinball. First those stuck up environmentalists were trying to save the fish and owls and ignoring the plain folks, then it’s those stuck up environmentalists are worried about climate change when they should be trying to save the fish and owls and a few toads.

    The truth is that Eli and others like him (think Jeff Harvey for example who often comments at Deltoid) HAVE been worrying about the loss of biodiversity driven by humans and one of the major ways we are killing off species is by climate change, both local and global.

    Start here for a 2001 take on this


    The current massive degradation of habitat and extinction of species is taking place on a catastrophically short timescale, and their effects will fundamentally reset the future evolution of the planet’s biota. The fossil record suggests that recovery of global ecosystems has required millions or even tens of millions of years. Thus, intervention by humans, the very agents of the current environmental crisis, is required for any possibility of short-term recovery or maintenance of the biota. Many current recovery efforts have deficiencies, including insufficient information on the diversity and distribution of species, ecological processes, and magnitude and interaction of threats to biodiversity (pollution, overharvesting, climate change, disruption of biogeochemical cycles, introduced or invasive species, habitat loss and fragmentation through land use, disruption of community structure in habitats, and others). A much greater and more urgently applied investment to address these deficiencies is obviously warranted. . . .

    There is consensus in the scientific community that the current massive degradation of habitat and extinction of many of the Earth’s biota is unprecedented and is taking place on a catastrophically short timescale. Based on extinction rates estimated to be thousands of times the background rate, figures approaching 30% extermination of all species by the mid 21st century are not unrealistic (1–4), an event comparable to some of the catastrophic mass extinction events of the past (5, 6). The current rate of rainforest destruction poses a profound threat to species diversity (7). Likewise, the degradation of the marine ecosystems (8, 9) is directly evident through the denudation of species that were once dominant and integral to such ecosystems.

    Thank you for bringing this to your attention

  12. Barry Woods

    it must be serious — there are Rabbett droppings everywhere…..

    If Mark doesn’t look out the big guns like – Jo Abbess and Bob Ward will turn up as well. Or, he will get awrite up by The Carbon Brief.

    Eli – this third person style – do you know ‘normal ‘ people just think you are a bit weird.

    What is interesting is more twittering and comments that George Monbiot and Mark LYnas have sold out to big nuclear !!

    1. David Bailey

      The real tragedy is that uranium/plutonium based nuclear power, is going to be expanded directly as a result of Greenpeace’s misguided exaggeration of AGW. Conventional nuclear reactors produce waste that has to be stored for thousands of generations – which can’t possibly be a safe thing to do.

      There is a considerable amount of evidence that the AGW scare has been hugely exaggerated, partly by the despicable trick of calling others who disagree, “deniers”, so that even when evidence comes to light – as it did in the leaked emails – most people don’t look!

      Interestingly enough, “big nuclear” doesn’t want to invest – the risks are to great!

    2. NickB

      What nonsense. Which “evidence” are you referring to that AGW has been “exaggerated”? Normally evidence is what is written up in peer-reviewed scientific journals, and this almost without exception supports AGW, to a degree that is stronger than is represented e.g. in the IPCC reports. You appear to be rather ignorant about the “evidence.”

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