By Kirsty Costa

How much are the world’s ecosystems worth?
$142.7 trillion annually. Approximately.

Mining, agriculture and tourism are some of the biggest pillars that hold up Australia’s economy and are all embedded in our natural environment. So it’s always baffled me how people can talk about ‘the economy’ and ‘the environment’ as two separate entities. If money really does talk the loudest, it’s time we had a conversation about how much our natural environment is actually worth.

Back in 1997, ecologist Dr Robert Constanza and a team of researchers set out to quantify the seemingly unquantifiable: the value, in dollars, of the world’s ecosystems. They came up with 17 categories of what ecosystems provide, which they labelled ‘ecosystem services’. There were the obvious things like food and raw materials but also less obvious things like flooding protection given by wetlands and forest conversion of carbon dioxide into oxygen. There were also categories for cultural and recreational uses of ecosystems.

The authors crunched the numbers and worked out how much we would have to pay to recreate ‘ecosystem services’ if they didn’t exist naturally. 15 years ago they estimated that cost to be around $33 trillion ($48.7 trillion in today’s dollars), which was more than the gross domestic product of the entire world in 1997.

Dr Constanza has recently returned to this project and now concludes that the 1997 estimate fell short. Based on data collected from a massive international survey of ecosystems and their relationships with human well-being, Constanza and his team now say that ecosystems are worth approximately $142.7 trillion. Much of the increase in costing comes from a better understanding of the value of our ecosystems.

For example, coral reefs have proved to be important for storm protection and reducing soil erosion. As a result, Dr. Costanza and his colleagues now estimate that each acre of reef provides $995,000 in services each year for a total of $11 trillion worldwide.

The bad news? The health of our ecosystems is diminishing and with it the current value of their services. Deforestation and other damage humans have inflicted on the natural environment has wiped out $23 trillion a year in ecosystem services (this is more than the $16.2 trillion gross domestic product of the United States).

You could argue that the total value of biodiversity is infinite, so having debate about monetary value is actually pointless because we can’t live without it. It would also be incredibly dangerous to just see ecosystems for their financial value and what they provide us human beings. But the reality is that ecosystems are already being seen that way. In his legacy speech, David Suzuki comments about how some people look at a forest and see a home for plants and animals as well as the stories of indigenous cultures, while others look at a forest and see profit.

To reach those who only see profit, why not cost out the services that are being destroyed? I’d argue that understanding what we have makes us more able to understand what we’re losing. If that’s monetary value, maybe we need to start talking about how much nature is worth so that people can see how many trillions of dollars we’re wasting both now and potentially in the future.

This article was based on the brilliant writing of Rebecca J. Rosen in her article ‘How Much Are the World’s Ecosystems Worth?’ in The Atlantic – www.theatlantic.com/business/archive/2014/06/how-much-are-the-worlds-ecosystems-worth/372862/

Read other CERES Education Our Say articles at http://dev.sustainability.ceres.org.au/project/our-say/ and join the conversation on social media.