would become market items from fur pelts, to fish, nuts, and so forth. t so long ago the natural world seemed to provide a limitless supply of free natural resources that we take for granted. We take so much from the world’s land, atmosphere, and waterways – everything from the air we breathe, to the pleasure we get from walking through a forest, or gazing at a magnificent landscape from a mountain top.
This was once referred to, quaintly, as ‘nature’s bounty’. However, to emphasise the critical role of nature in human commerce and society, the language of sustainability science now uses the much less colourful and more market-orientated expression ‘ecosystem services’ to mean essentially the same thing.
This economic metaphor refers to natural resources as ‘natural capital’) because they are capital assets needed for the flow of services: they cannot be depleted without serious consequences. The metaphor is sometimes pushed further to discuss items like ‘natural infrastructure’ like rivers, forests, wetlands and so on.
The idea of ‘ecosystem services’ also highlights the fact that we treat many natural assets as if they had no, or little, value. Assets held in common, like the air we breathe, are not owned by anyone, and can therefore be exploited and degraded. The atmosphere is degraded by us all, but action on climate change is still a confused and contentious matter. Clearing forests, building housing along coastlines, adding CO2 to the atmosphere and many other environmental impacts generally benefit only a small sector of society while overall natural capital is eroded.
As natural resources become depleted we are becoming increasingly aware of our need to protect what is left, so in recent years we have seen the increasing use of market mechanisms (carbon and water credits, taxes, financial incentives etc.) to tackle the problem of nature being treated as an economic externality.
The following diagram produced in in the Millennium Ecosystem Assessment (2005) captures important links between the environment, society, economics, and our sense of well-being. It is the attempt to integrate all those factors that are collectively at the heart of what we mean by sustainability: it is about ‘… the overlooked resources upon which human welfare, wealth creation, and quality of life depend.
Chart indicating the major environmental factors that influence human wellbeing
Courtesy Millennium Ecosystem Assessment 2005
This article examines the many ways in which humans depend on nature, the community of life. These are biogeochemical resources that are necessary for life to exist at all, not just those that enhance our lives. Expressed in the simplest terms our integration with the world begins with our depenedence on interactions with inorganic energy, water, and materials – although as living organisms we interact in many ways with our fellow organisms, the community of life (biodiversity or the biosphere) which is our source of food. Although all these factors are closely integrated, their significance is addressed in independent articles on elements of both geodiversity (energy, water, materials) food as a requirement for life, and biodiversity.
History & resources
We do not read much about about resources in history books because their presence in our lives, like the air we breathe, is generally taken for granted, they are a given. Besides, we are accustomed to history emphasizing political and cultural matters. Now, in the 21st century, it is clear that natural resources can no longer be taken for granted. As the Anthropocene unfolds we are becoming increasingly aware of our influence on the planet and our interaction with the community of life.
Expanding populations, improved transport and technology, urbanization, and globalization have led to longer and more interconnected transport routes, more remote supply chains, vastly more traffic, and a greater diversity of goods. Global short-supply increases awareness of the role played by ecosystem services in human lives of the past since only now do we realize their potential to affect our future sustainability. If human history is the attempt to track those factors exerting the greatest influence on the course of individual and collective human lives then our awarenss of the potential impacts of diminishing resources now prompts us to look back to the factors that created this circumstance. We now look back, with the benefit of hindsight, at the significance of the environment in not only traditions and belief, but as the manipulation of flows of energy, water, materials, and organisms that have created civilizations and artificial (human or man-made) landscapes across the world. This is yet another reinterpretation of history made necesssary by present circumstances and performed as preparation for the future.
Categorizing ecosystem services
In any complex interactive system the choice of categories to describe and explain that system can be a difficult matter. The choice of provisioning, regulating, cultural, and supporting services reflects qualitative differences – other classifications might have different criteria. This classification draws attention to non-material (psychological or spiritual) benefits as wellbeing in addition to direct physical goods and services. There is a cascade of ideas from ecosystem, to function, to service, to benefit, to value that is the foundation for an environmental ethic. Markets at present do not do enough to recognize these values and the contribution made to the trade in goods and services.
Scarcity & substitution
In economics the loss of a resource can be addressed by replacing it with another as ‘substitution’. Ploughed grassland might provide arable land for the service of food production. But since ecological interactions are complex we cannot be sure of either the long term effects and the impact on other ecosystem services. technology can certainly provide some substitution capacity. What we do know for sure is that ecosystems are not limitless so our economics must take this into account: only a clear understanding of the operations of ecosytems and their natural limits must underpin any program of substitution.
Life has existed on Earth for more than 3.5 billion years with species extinctions a normal part of the evolutionary process. However, when the loss of species rapidly exceeds the emergence of new species we enter a ‘mass extinction’ event generally defined as a loss of about 75% of all species over a short geological time period (<2.8 million years).
Around the Cambrian period about 540 million years ago there was a sudden proliferation of life forms and since that time there have been five extinction events that meet this criterion and which help determine whether human beings have today created the conditions for a sixth mass extinction.
Five mass extinctions
The world’s five mass extinctions have occurred on average every 100 million years since the Cambrian (although there is no clear pattern to their timing) and each extinction event lasted between 50,000 and 2.76 million years.
First mass extinction
At the end of the Ordovician period c. 443 million years ago obliterating 85 per cent of all species. Probably a consequence of two climatic events: a planetary-scale period of glaciation (a global-scale “ice age”); followed by a rapid warming period.
Second mass extinction
In the Late Devonian period c, 374 million years ago the second mass extinction killed around 75 per cent of all species, most being bottom-dwelling invertebrates in tropical seas. This period had high variation in sea levels and rapid global cooling and warming when plants (Pteridophytes) were starting to cover dry land with a drop in global CO2 concentration with soil transformation and periods of low oxygen.
Third mass extinction
The most destructive of all extinction events this occurred at the end of the Permian period around 250 million years ago, wiping out more than 95 per cent of all species. Probably the result of an asteroid impact that filled the air with toxic particulate matter and altering the climate, concealing the sun and generating acid rain. Other theories suggest volcanic activity in today’s Siberia, increasing ocean toxicity with an increase in atmospheric CO2 – or the spread of oxygen-poor water in the deep ocean.
Fourth mass extinction
Fifty million years after the great Permian extinction, about 80 per cent of the world’s species were again obliterated in a Triassic event, probably the result of geological activity in today’s Atlantic Ocean, raising atmospheric CO2 levels, increasing global temperatures, and acidifying the oceans.
Fifth mass extinction
In the Cretaceous about 145 million years ago dinosaurs were struggling until wiped out by an asteroid impact when about 76% of all species became extinct. This was an impact in the Yucatán of modern-day Mexico, a massive volcanic eruption in the Deccan Province of modern-day west-central India, or both in combination. This gave mammals an opportunity to diversify and occupy new habitats, from which human beings eventually evolved.
The most likely cause of the Cretaceous mass extinction was an extraterrestrial
Sixth extinction event
The Earth is currently experiencing an extinction crisis resulting from planetary exploitation of resources by human beings although whether this constitutes a sixth mass extinction depends on whether today’s extinction rate is greater than the ‘background’ rate that occurs between mass extinctions which indicates how rapidly species would die out in the absence of human activity using mostly fossil evidence. The generally accepted figure suggests an average lifespan of about 1 million years for a species, or one species extinction per million species-years. But this estimated rate is highly uncertain, ranging between 0.1 and 2.0 extinctions per million species-years and depends an accurate figure.
Extinction has many direct and indirect human causes: the destruction and fragmentation of habitats; exploitation by fishing and hunting; chemical pollution; swamping by invasive species; global warming and more. The rate of extinction appears to be between 10 and 10,000 times higher than the background rate.
Among land vertebrates (species with an internal skeleton), 322 species have been recorded going extinct since the year 1500, or about 1.2 species going extinction every two years.
If this doesn’t sound like much, it’s important to remember extinction is always preceded by a loss in population abundance and shrinking distributions.
Based on the number of decreasing vertebrate species listed in the International Union for Conservation of Nature’s Red List of Threatened Species, 32 per cent of all known species across all ecosystems and groups are decreasing in abundance and range. In fact, the Earth has lost about 60 per cent of all vertebrate individuals since 1970.
How does Australia fit into the pattern?
Australia has one of the worst recent extinction records of any continent, with more than 100 species of vertebrates going extinct since the first people arrived over 50,000 years ago. And more than 300 animal and 1,000 plant species are now considered threatened with imminent extinction.
Although biologists are still debating how much the current extinction rate exceeds the background rate, even the most conservative estimates reveal an exceptionally rapid loss of biodiversity typical of a mass extinction event.
In fact, some studies show that the interacting conditions experienced today, such as accelerated climate change, changing atmospheric composition caused by human industry, and abnormal ecological stresses arising from human consumption of resources, define a perfect storm for extinctions.
All these conditions together indicate that a sixth mass extinction is already well underway.
Adapted from an article in The Conversation by Frederik Saltre and Corey J A Bradshaw.
Commentary & sustainability analysis
The model of ecosystem services presented here presents an antropocentric framework of ideas … it is about nature as human utility that provides wellbeing. Nevertheless, human wellbeing mostly coincides with the wellbeing of the rest of the community of life. The idea itself provides a mechanism for introducing a consideration of nature into public policy providing the language and tools needed to guide us towards a sustainable future.
If this tool interests you then you can enrol, free of charge, in the Ecosystem Services Coursera program.