The mainstream media excites their readers and listeners with many things. Fall under their spell and you would almost be forgiven for thinking that the biggest threat from climate change, if you still believe the scientific facts as opposed to columnists’ opinions, will be upon the size of your wallet.
Professor Roger Kitching reminds us of the real and present threats and that the diversity of Australian wildlife will be the first to suffer.
A biodiverse Australia is under threat. Image:greghardwick.com.au
Biodiversity! – kangaroos, kookaburras, possums, willie wagtails, bluetongues – perhaps even birdwing butterflies and funnel-web spiders – all things we might associate with this (relatively) new word.
But what about a couple of other lists - ‘Aberdeen Angus, Ayrshire, Santa Gertrudis, Friesian, Jersey and Charolais’ – or ‘rainforests, grasslands, deserts, tundra, coral reefs and eucalypt woodlands’ – these, too capture something essential about this thing we call ‘biodiversity’.
Biodiversity is nothing more nor less than the entire diversity of life – within a species, species themselves, and sets of species. Let’s put this another way, the essential diversity of life on Earth includes genetic diversity within species – all those and many other races of cattle, for instance; species themselves – the familiar original list and many million more; and, ecosystem diversity – the list of ecosystems mentioned and many more made up of repeatable sets of species on the landscape.
The modern conservation movement was triggered in the late 1960s by Rachel Carson’s epic book ‘Silent Spring’.
Carson focused popular attention on a trend which biologists had been aware of over century – first, in fact, given voice by Darwin’s prescient, polymath co-worker, Alfred Russell Wallace – that the number of species on Earth was gradually diminishing – not by the slow inexorable processes of extinction on a geological time-scale, but through the landscape changes imposed by human ‘development’ – by clearing, agricultural chemicals and housing developments as well as the more direct impacts of hunting and gathering to satisfy an exponentially growing human population.
Rachel Carson’s agenda focussed on the species and the consequences of the outcry that followed publication of her book took the form of ‘red lists’ of threatened and endangered species around the world and tentative legislation to prevent their slide into oblivion.
At the time of publication of Carson’s book the global estimate of species diversity on Earth was about 3 to 3.5 million. This tally was confidently made up of about 10,000 species of birds and 5000 species of mammals (mostly rats, mice and very small bats).
The remaining 3 million or so were principally insects and their relatives. So I was taught as a university student in the early sixties. In 1982 Terry Erwin from the Smithsonian Institute in Washington introduced rainforests, canopies and the tropics into the equation.
Based on some rather preliminary estimates of the number of different beetle species in the canopies of one species of tree in Panama he made the outrageous extrapolation that there were probably 30 million species of insects and their relatives in the tropical rainforests of the world.
We now know that this was indeed an overestimate – the ‘true’ figure may be nearer 7 to 10 million – although the jury is still out on the actual number. Nevertheless Erwin’s huge estimate, its association with rainforests and the observation that rainforest were being cleared faster than ever before, led to the biodiversity crisis of the 1980s and 1990s.
Indeed it was in that welter of concern that the organiser of a 1988 symposium on diversity and conservation coined the term ‘biodiversity’ – contrary to popular belief this was not the famous American biologist E. O. Wilson, although he edited the book in which the term first saw the light of day.
Indeed, Wilson assured me he opposed the coining of such a gauche neologism – but subsequently regretted not having coined the term, which subsequently took off in the public and political imagination.
Bringing the many, many species of invertebrates (which includes the insects) into the picture gave the whole biodiversity ‘movement’ a huge boost – its promoters were able to talk loosely but portentously of how many species were being lost in a day, a week, a year and so on – usually estimated in terms of the number of ‘football fields’ of rainforest being cleared. But this boost contained the seeds of its own demise. Very soon sceptics began to ask, for example, why some tiny, recently discovered soil mite was to be given the same weight as the mighty tiger, rhinoceros or giant panda – legally if not in the wider public mind. Lists of threatened and endangered insects have been drawn up and given legal protection. Do you know for example, that in Western Australia a whole raft of tiny Crustacea found nowhere else but in water-filled crevices deep in the Earth are not only protected under legislation but have caused vast mining projects to be relocated or delayed at costs which make the proposed resource tax seem like peanuts?
The real value of the invertebrates and indeed the even smaller and less well-understood micro-organisms, is not as ikons of the magnificent or the soon to be lost – these are not thylacines or paradise parrots – but as tiny cogs in the maintenance of the life-support systems on which they, and us, depend totally. In the late 1990’s the biodiversity emphasis rightly changed to a focus not on each individual species but onto the idea of ecosystems and ‘ecosystem services’. In a nutshell these are the many benefits we get from functioning ecosystems which, were they not there, we might have to pay for (or try to pay for, assuming there was an appropriate service provider). These services include nutrient storage and movement, soil building, water purifying, the maintenance of local climate, the natural control of potential pests, pollination, waste recycling, pharmaceutical products, even the fine forests, reefs and rivers that feed our tourism industry. It is hard to estimate the dollar value of these ‘services’ simply because we are not accustomed to having to pay for them but such estimates as have been attempted fall consistently into the many billions or even trillions of dollars. The problem with these estimates, as I said before, is that they carry the implicit assumption that were these ecosystem services to be destroyed then we, somehow, could buy replacements – this is not the case! Humanity at large depends intimately on being surrounded by functional ecosystems.
Professor Roger Kitching from the Griffith School of the Environment, Griffith University.
You could be forgiven for thinking that these are simply the burblings of academics or other stirrers who have been out of the ‘real world’ for too long. Yet contemplate the slow death of the River Murray that we are currently watching. Think about the dieback affecting our Tablelands and its consequences on local soil conservation, fertility and micro-climate. Observe the gradual encroachment of agricultural lands by desert. Peer in horror at the leprous landscape of ex-irrigation lands scarred probably for ever by salting. Watch the bleaching of coral reefs to unattractive ghosts of their past glories. These are not intellectual maunderings but real disasters – human made and not readily ‘fixable’.
So much of human history has taken place in a world where there was always more – more lands to conquer, more forest to clear, more seas to fish. Our increasingly sophisticated technology allowed us to do this. Once the forests of Western Europe were cleared we could send our fleets to find forests elsewhere – and there always was an elsewhere – from the point of view of tropical hardwoods this is currently Papua New Guinea. But there are almost no frontiers left: we have not learnt the lesson of sustainability – all political rhetoric notwithstanding. Why are we in Australia having a debate about whether or not to control our population size, on the one hand, while advocating ‘sustainabilty’ on the other. Population growth and sustainability are oxymoronic concepts.
So in this Year of Biodiversity 2010 what are the greatest threats to the biodiversity on which our future depends. In Australia three pervasive inter-related threats promise to wipe out great chunks of the very special biodiversity with which this once-isolated continent is endowed: land clearing, invasive species and climate change. Mixed up with these three are drivers such as inappropriate fire regimes, pervasive agricultural chemicals and lack of connectivity across the landscape. Anyone of these ideas deserves a whole book not just a short article. Let me dwell finally then on the most all-pervasive of them, climate change.
All the predictions of climate models show Australia as a whole becoming warmer and drier with a shift in patterns of rainfall away from the south-east, and an increase in the number of extreme events such as cyclones and droughts. Predictions of how serious these changes will be vary from model to model. One thing is certain though, without prompt urgent mitigation we are heading for the worst of any range of modelled scenarios. Recent global data collected since the famous set of IPCC Predictions were made, show us tracking at or above the most extreme of the predictions whether we are talking about temperature or sea-level. Some of the first impacts we will see – indeed are seeing already – will be upon biodiversity. Mountaintop ecosystems will be the first to go – in Australia the unique faunas of our subtropical Antarctic Beech forests and the endemic marsupials and birds of our tropical mountains will likely not withstand the most mild of heating trends. And all this will impact on us through an undermining of the ecosystem services provided by this biodiversity.
The recently published book on Australia’s biodiversity and climate change of which I was one of eight authors (Steffen et al. ‘Australia’s Biodiversity and Climate Change’, CSIRO Publishing, Melbourne, 2009) makes many suggestions as how we might cope with these predicted changes. I close with just two of these. First we need to start thinking about and managing biodiversity as whole inter-connected sets of species driving complex ecosystem-level processes – retaining our species-centricity for the ikonic symbols of conservation – the striped bandicoots, hairy-nosed wombats and bilbies. Second, we know that ecosystems and the organisms that comprise them have some capability of adapting – not without change and loss of species – but possibly sufficiently to keep the essential services going. For this ‘resilience’ to be maximised we need to minimise other stressors imposed on biodiversity. We need to keep our National Reserve System in good order, indeed keep expanding it – it will be more vital than ever under climate change. We must restore our landscape to put connectivity back into the environment so that natural species have some hope of re-sorting themselves into new ecosystems as the climate vice tightens. The control of environmental pests and the strict quarantine that minimises their occurrence must be maintained – even in the face of probably unwinnable wars against, for example, invasive ants. Precious water must be partitioned to allow due amounts to the natural environment itself – this is not water ‘wasted’ but water expended on our own well-being through the services provided by healthy ecosystems. The list goes on. Most important of all we need to keep educating people to realise this threat is real and action is essential.
The science is incontrovertible and the few highly vocal nay-sayers deserve no more than pity. Every month delayed through the playground fights in Canberra or the bully-boy tactics of special interest groups, makes the task of recovery that much harder.
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