Of course we want to save the panda. Pandas are cuddly, furry and charismatic, and even cuter when they sneeze. But a new approach to conservation policy suggests that we ought to be prioritising our efforts in a different way. The Evolutionarily Distinct and Globally Endangered (EDGE) index aims to measure how "evolutionarily distinct" (ED) a given species is, with the idea that more evolutionarily distinct species are more worth preserving.

Conservation is, on the whole, a worthwhile aim; let us take that as read. But, in a world where thousands of species are in imminent danger of extinction, how should we focus our efforts? Certainly it may be useful to develop metrics such as the EDGE index to help us assess how we should prioritise in making decisions about which species to save. Without an account of what it is we value about biological species and why, however, these numbers are meaningless; we might as well be measuring size, or colourfulness, or some other arbitrary trait.

So, why is evolutionary distinctness valuable? There are of course many possible answers to this question: the 'weirdness' of a species may correlate with its significance within an ecosystem, its potential uniqueness, its value to science and related applications. The point stands, though, that we need to be aware of where this value lies, if we are to base our actions upon it. In setting conservation policy we need to define what we consider to be valuable and why, and understand how the statistics presented to us reflect this.

The fact that humans do not score highly on the ED scale should serve as one illustration of this point. Of course, we are very far from endangered, and it may be that many ecosystems would be just as stable without us or even more so. But we are also one of a very few (perhaps even the only) species on this planet that possesses the capacity to be consciously aware of our environment and our own existence, of how our actions can affect the world around us, and what implications this may have for our future existence and the future of all life on this planet.

Is our life and that of creatures like us something that we ourselves value? Do we prefer a world in which we and other conscious, self-aware, thinking and reasoning beings exist, can contemplate the world around us, can create and appreciate art and science and philosophy? If so, we must acknowledge that evolutionary distinctness is not the be-all and end-all of conservation; it may represent some aspects of species value but it is not the only thing we value in life.

What are our moral responsibilities, then, with regard to conservation of species, ecosystems and environments? We may view the environment as a resource to be used for the good of humankind; alternatively we may decide that, because we are moral agents, capable (in theory at least) of distinguishing right from wrong and making decisions accordingly, we have a duty of stewardship, to care for the environment, precisely because we understand what it means to do so. In either case, however, we still need a coherent account of what constitutes right and wrong in relation to our actions and their effects on the environment.

It is almost certainly the case that our collective actions on this planet today are exhausting natural resources faster than they can be replenished, resulting in detrimental effects for humankind in the long (and even short) term, and that they are not showing the care for the environment that we can and perhaps should be exercising. But to produce a convincing case for policy change, we need a convincing moral case, and that of necessity relies on establishing sound moral reasons as to what we should be aiming to achieve and the values underlying this aim.

Another factor in considering how to make such a case effectively is the importance of precisely identifying adverse consequences and their significance in terms of these clearly-defined values. The "crime of ecocide", referring to the destruction of ecosystems rather than species, is a recent example that highlights this. Of course it is important to recognise that for some purposes, protecting ecosystems is as important as protecting species. One species may become extinct while another takes its place, but the ecosystem remains functional and in equilibrium; if an entire ecosystem is destabilised, the consequences may be far more severe.

Certainly 'ecocide' may be regarded as a more grievous offence in terms of its real-world consequences than single-species extinction, and we should raise awareness of its significance. But the language in which this argument is couched does not necessarily reflect its true importance. Ecocide is first described as being "crimes against nature". But what is a crime against nature? Does vaccination, or any other act that preserves human life and health but goes against the course of nature, constitute a crime? "Crimes against peace and humanity" are obviously a bad thing, but it is likewise far from clear how ecocide constitutes either. Such vague appeals to nature are not just morally imprecise, they are also semantically and practically fuzzy. In today's hard-nosed and (unfortunately) dollar-driven world, it is all too easy to set such rhetorical devices aside in favour of more concrete arguments that would have us disregard conservation and preservation of ecosystems for the future to achieve short-term gains.

To conclude, and to be absolutely clear, I am a fervent supporter of many environmental preservation and species conservation initiatives and believe these are often worthwhile goals. And when it comes to translating these moral goals into policy, I want to see the arguments for doing so framed as effectively as possible – because this will be a crucial factor that allows us to make a difference in the real world.

As noted, we humans are aware of our existence and our place in the world, and this may shape our ideas of what it is we value about the world around us. What we do with this awareness, how we apply it to make decisions about our own actions and by extension the future of our environment and this planet, is up to us. And once we have decided what the right course of action is, we need to make a solid case as to why we (and our politicians) should collectively pursue this course. For anyone who cares about conservation -- of species, ecosystems, and environments -- clearly enunciated moral values and reasons, not just statistics or rhetoric, will be vital in doing so.

Image credit: George Lu