No-extinction targets are destined to fail

21 09 2012

I’ve been meaning to write about this for a while, and now finally I have been given the opportunity to put my ideas ‘down on paper’ (seems like a bit of an old-fashioned expression these days). Now this post might strike some as overly parochial because it concerns the state in which I live, but the concept applies to every jurisdiction that passes laws designed to protect biodiversity. So please look beyond my navel and place the example within your own specific context.

As CB readers will appreciate, I am firmly in support of the application of conservation triage – that is, the intelligent, objective and realistic way of attributing finite resources to minimise extinctions for the greatest number of (‘important’) species. Note that deciding which species are ‘important’ is the only fly in the unguent here, with ‘importance’ being defined inter alia as having a large range (to encompass many other species simultaneously), having an important ecological function or ecosystem service, representing rare genotypes, or being iconic (such that people become interested in investing to offset extinction.

But without getting into the specifics of triage per se, a related issue is how we set environmental policy targets. While it’s a lovely, utopian pipe dream that somehow our consumptive 7-billion-and-growing human population will somehow retract its massive ecological footprint and be able to save all species from extinction, we all know that this is irrevocably  fantastical.

So when legislation is passed that is clearly unattainable, why do we accept it as realistic? My case in point is South Australia’s ‘No Species Loss Strategy‘ (you can download the entire 7.3 Mb document here) that aims to

“…lose no more species in South Australia, whether they be on land, in rivers, creeks, lakes and estuaries or in the sea.”

When I first learned of the Strategy, I instantly thought to myself that while the aims are laudable, and many of the actions proposed are good ones, the entire policy is rendered toothless by the small issue of being impossible.

Extinctions are, of course, a normal part of life, at least over geological time scales1,2. However, the rapidly expanding human population has put such pressure on the Earth’s resources that we have now entered the sixth mass extinction event now dubbed ‘The Anthropocene3. In a local context, Australia has the highest current extinction rate of mammals in the world4, and we have lost nearly 40% of our forest cover since European colonisation5. South Australia in particular has seen extensive habitat loss, local extinctions and habitat degradation (you can see some of the evidence for this in South Australia’s State of the Environment reports).

That’s bad enough, but the major damage has been done and we’re now on track to rectifying the limited vision of past, right? Wrong.

Unfortunately, degradation of the past has not yet wreaked the havoc on species due to a phenomenon known as ‘extinction debt6. This well-demonstrated component of extinction means that extinctions continue years, decades and sometimes centuries past the major environmental perturbation. Thus, even if a comprehensive, state-wide and massive ecological effort were to begin tomorrow in South Australia (another unlikely scenario), we would still be committed to decades of extinctions from past degradation. These are not wild, uncertain concepts – these are well-established facts.

Combine this notion with the observations that few, if any, of the indicators used to track biodiversity change in South Australia are suggesting improvement, and the Strategy loses credibility. It is therefore beyond avoidance that extinctions will continue in South Australia regardless of our actions. Of course, we can slow the process, but we cannot possibly meet the policy targets set by the Strategy.

Now, some people might suggest that the Strategy’s ‘No Species Loss’ title shouldn’t be taken literally and of course we cannot avoid all extinctions, but this sentiment isn’t expressed anywhere in the document. It is therefore disingenuous to the public that such a bold, yet fantastical policy exists at all. Some could also argue that a mere word change would rectify the problem – I disagree. The entire notion of triage is ignored here because it implicitly assumes that there is no hierarchy or prioritisation necessary.

My intention here is not to denigrate my respected colleagues in the State government (and I do actively work with many of them); rather, I seek to stimulate the responsible bureaucrats to listen to the relevant experts to address these important gaps in our environmental policies. Otherwise, what happens when (and not if) we fail? Do we simply say ‘oh well’, admit defeat, and continue on as before? It seems to me that this is an overly naïve way of proceeding, and it does not embrace the fountain of ecological knowledge we have already tapped. Let’s be cleverer about how we approach biodiversity conservation.

CJA Bradshaw


  1. Raup, D. M. Biological extinction in Earth history. Science 231, 1528-1533, doi:10.1126/science.11542058 (1986)
  2. Raup, D. M. The role of extinction in evolution. Proc Natl Acad Sci USA 91, 6758-6763, doi:10.1073/pnas.91.15.6758 (1994)
  3. Crutzen, P. J. Geology of mankind: the Anthropocene. Nature 415, 23, doi:10.1038/415023a (2002)
  4. Johnson, C. N. Australia’s Mammal Extinctions: A 50 000 Year History.  (Cambridge University Press, 2006)
  5. Bradshaw, C. J. A. Little left to lose: deforestation and forest degradation in Australia since European colonization. J Plant Ecol 5, 109-120, doi:10.1093/jpe/rtr038 (2012)
  6. Tilman, D., May, R. M., Lehman, C. L. & Nowak, M. A. Habitat destruction and the extinction debt. Nature 371, 65-66, doi:10.1038/371065a0 (1994)



11 responses

20 05 2022
Fallacy of zero-extinction targets |

[…] a decade ago (my how time flies*), I wrote a post about the guaranteed failure of government policies purporting no-extinction targets within their […]


25 02 2015

Your points are all accurate, but I agree with the comment above of the need to be aspirational with policy goals.

“To boldly go where no one has gone before” was a great tagline, even though some members of the Enterprise’s crew were not always bold, and many episodes took place in locations that they had indeed been before. “To cautiously go where only a couple people have been before, while considering all the restrictions of the current scenario” is more accurate but not nearly as compelling.


20 10 2014
It’s not all about cats |

[…] as others have already eruditely stated, we will never, ever eradicate them. Moreover, we will not ever stop extinctions – the best we can do is slow them down. I also take particular issue with highly subsidised, industry-led push to cover the land in a new […]


16 04 2014
South Australia’s tattered environmental remains |

[…] State has an unachievable and distracting ‘lose no species’ policy (see here for […]


20 11 2012
Dead and dying: our great mammal crisis « endoftheicons

[…] No-extinction targets are destined to fail ( […]


15 10 2012
Marty Deveney

When this policy was first proposed as a draft for public consultation I sent a letter to the relevant department congratulating them on reversing the major functional transitional measure of Darwinian evolution.



15 10 2012

LOL. Cheeky bugger. But you’re spot on.


14 10 2012
Kieran Suckling

Your are certainly correct that extinctions will continue to occur because we are not even close to adequately protecting biodiversity and habitat. However, your equation of this fact with a policy of opposition to legislation which requires saving of all species needs to be thought more. Politics is rightfully and properly about aspiration as much as it is about implementation. Whether fully met or not–and it rarely is–the aspiration plays a critical role in expressing, extending and codifying societal ethics. That is the proper realm of politics.

To suggest that we remove the aspiration–in this case, allowing extinction–due to the fact that full implementation is not possible dangerously misses the point of politics. Consider a different arena. We have codified the social ethic of equality in legislation that prohibits racism. These laws will not succeed. People will continue to commit racist acts. Should we therefore amend the laws to be realistic about this fact? Should they instead allow “some” racism? Of course not. Some racism is not morally acceptable even though it is socially inevitable. The laws were not passed with the expectation of perfect compliance, they were past to substantially improve conditions and to express our social values.

So, should our legislation allow us to drive some species extinct just because we know that is likely to happen no matter what? No. In addition to floundering on the very dangerous, politically unstable rock of inviting industry groups to start lobbying land managers for which species to drive extinct (do you really think the political system will ask scientists to provide the extinction list?), such legislation would undermine society’s ethical values.


11 10 2012
Geoff Russell

We won’t be able save all species but we can roll back our footprint. We have to anyway as a consequence of the 1 tonne sustainable per capita CO2eq target set in the Copenhagen Diagnosis report. Apart from a nuclear roll out, which requires no behavioural changes, other than thinking rationally :), our environmental footprint, and a huge part of any sustainable CO2eq footprint will be determined to a first order approximation by what we choose to eat This is pretty much what drives land use patterns. Australians live on 2 mHa, crop 25 mHa and graze 400 mHa (with most of the cropping output used as feed). So we really only need one behavioural change and for many of the 7 billion it isn’t really a change at all.


1 10 2012
Why do conservation scientists get out of bed? «

[…] inevitable extinctions […]


21 09 2012
Michael McCarthy

A flurry on Twitter emphasized that triage is not simply a question of letting some species go extinct. It is a matter of figuring out what you want (measured by biodiversity; perhaps weighting some aspects as more important than others), and then working out the most efficient way to get that. The extinction of some species is the consequence; but not doing triage would lead to more loss of biodiversity. This is one of the basic points of Corey’s post.

Given current levels of funding, Corey is right that extinctions should be expected. There are choices to be made. This topic has been explored in the literature (e.g., Bottrill et al. in TREE:

Hugh Possingham and I have addressed the topic of the public needing to face up to extinctions and take responsibility for *informed* choices.

The one interesting thing that has not been addressed formally in quantitative approaches to triage is the topic that @silverlangur noted on Twitter – leverage. Actions to try to save some charismatic species or ecosystems can help engender support for other aspects of biodiversity that might suffer from image problems. How that influences net funding for global and local conservation actions, and hence how it influences optimal allocation of funding, is unclear.


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