The Babel fish is one of the more inspired forms of fictional biodiversity. It features in the Hitchhiker’s Guide to the Galaxy by Douglas Adams (sadly no relative), and allows his antihero, the ape descendant Arthur Dent to traverse the universe with only his speaking handheld digital assistant, the Hitchhiker’s Guide, for company (forget Siri, Douglas Adams got there first).  The Babel fish is described as ‘small, yellow and leech-like’, and when it had slithered into Arthur Dent’s ear, he could understand anything that was said, in any language of the universe.  As usual in the Hitchhiker’s Guide, this turns out not to be entirely a good thing.

Many conservationists seem to hope that ecosystem services will work like a Babel fish for them.  For decades they have hammered on about how valuable nature is, and nobody has paid much notice.  Humanity blithely goes on strip mining the earth’s stock of natural capital and burning it getting rich, or just keeping alive. But the ecosystem services Babel fish promises to change all that.  Insert it into public discourse, and when conservationists speak of wildlife, biodiversity, endangered species or habitat loss, their listeners will hear human wellbeing, natural capital, nature’s supply chain, the stuff humans get for free.   When we speak about the importance of conservation, everyone will automatically understand what we mean.

The Babel fish of ecosystem services works by translating conservationists’ ideas about nature into the language of economics.  The idea is that economists in their turn can use it to explain why the conservation of nature matters, because the language of economics already has the ear of policy makers and the public.  The romantic attachment between conservation biology and environmental economics has been growing for several decades, inspired by work like the late David Pearce’s Blueprint for a Green Economy, and Robert Costanza’s classic attempt to calculate the value of the world’s ecosystem services and natural capital in 1997.  The Millennium Ecosystem Assessment, the TEEB reports, and the UK’s National Ecosystem Assessment all servce, with different degrees of success, to ‘make nature economically visible’, as the TEEB’s mission expresses it.

So far, so good, but the thing about interpretation is that it is never perfect.  What people hear is often not quite what was meant.  This is particularly true where we talk not about concrete things, but in word pictures.  Ecosystem services is not really a translating fish, but a metaphor, and, as Mary Midgely observed in New Scientist in 2011, ‘the trouble with metaphors is that they don’t just mirror scientific beliefs, they also shape them. Our imagery is never just surface paint, it expresses, advertises and strengthens our preferred interpretations’.

One of the problem with metaphors is that you stop noticing them.  Richard Noorgard points out that the idea of nature as a fixed stock of natural capital that sustains a flow of ecosystem services is no longer the eye-opening metaphor it was in the early 1990s.  Instead of a means to communicate the delusion of endless growth, it has become a dominant model for environmental policy, supporting as thriving industry of professionals.  In the banal language of everyday politics, ‘we need to recognise that if we withdraw something from Mother Nature’s Bank, we’ve got to put something back in to ensure that the environment has a healthy balance and a secure future’.

A second problem with metaphors is that something is lost in translation.  Michel Sandel makes this point about the idea of the market in his book What Money can’t Buy.  Markets leave their mark, he says: they can crowd out important nonmarket values: market reasoning empties public life of moral argument.  This kind of point has been made in the context of conservation – for example Douglas McCauley argues: ‘if we oversell the message that ecosystems are important because they provide services, we will have effectively sold out on nature’.

A third problem is that is that metaphors develop a life of their own. The metaphor of ecosystem services triggers what Emory Roe calls a policy narrative, a story that secures a basis for policy action.  The idea of ecosystem services is taken to mean not only that nature has an economic value that needs to be calculated carefully and taken fully into account in any economic decisions (undoubtedly true), but also that markets can be created to determine that value and trade in associated commodities.  Cue market-based conservation, payments for ecosystem services and novel commodities like carbon futures.  Welcome Noorgard’s thriving industry, a diverse community of economists (ecological, economic, political, institutional) attempting to measure flows of services from different ecosystems under different conditions, and to work out who wins and who loses in the resulting scramble for benefits.  Welcome too businesses, who see opportunity in the idea of ecosystem services, in terms of new products, new brands and an escape from regulation.

These (and others like them) are not novel points about the challenges of applying the ecosystem services approach to biodiversity conservation.  Each can be debated, as to the extent to which it is happening, and whether (and for whom) it is a good thing.  My point is not the problems or the potential, but the power of the metaphor of ecosystem services, and the narrative that it drives.  They are taking conservation to strange places.  Mary Midgely is quite right, metaphors shape our belief and the idea of ecosystem services is transforming conservation is ways that are only slowly becoming apparent.

Perhaps the most worrying thing about the ecosystem services Babel fish is whether, ultimately, it works. Economists may like the idea of ecosystem services, and politicians, policy-makers and business leaders may find it useful, but the acid test is whether it helps ordinary people understand what conservationists care about, and why. Morgan Roberston, on his Wetlandia blog, suggests it may not: a 2010 opinion survey for the Nature Conservancy in the USA found that ecosystem services ranked 13^th out of 16 terms used to describe the benefits of nature (natural capital was 15^th). Conservationists (with the economists and policy makers they like talking to) appear to be in a bubble, mouthing unintelligible jargon to the bemused citizens of planet earth.  Business as usual in the world of planet management, in fact.  Tony Juniper tells me that his new book What has Nature Ever Done for Us (due out in January 2013) manages not to use the term ecosystem services at all.  Maybe he is onto something.

Douglas Adams knew a thing or two about conservation and extinction, and he never underestimated the power of the absurd.  The Hitchhiker’s Guide records the sad fact that ‘the Babel fish, by removing all barriers to communication between different races and cultures, has caused more and bloodier wars than anything else in the history of creation’.  He envisaged the races of the universe understanding only too well that they had nothing in common.  Maybe conservation will have the reverse problem, if the ecosystem service Babel fish doesn’t translate its ideas very well.

Either way, my conclusion is simple: beware the blandishments of the fish in your ear.