Ecosystem services: changes in global value
It is well recorded that ecosystems are becoming more stressed over time, with pressures such as human population increases leading to biodiversity and habitat loss. The provision of ecosystem services from habitats and communities is vital to human well-being. It is important to understand the benefits ecosystem services provide to society and how they have changed over time to build an understanding of our reliance on the natural world and what needs to be done to ensure we can continue to benefit from these services in the future. Building on estimates of the global value of ecosystem services in 1997, a recent paper in Global Environmental Change by Robert Costanza et al. highlight the impact that global land use changes have had on ecosystem services. They estimate that between 1997 and 2011, ecosystem services to the value of $4.3-$20.2 trillion per year have been lost.
The goods and services we use in our daily lives derive from 5 types of capital: financial, manufactured, social, human, and natural. Natural capital encompasses the elements of nature that directly and indirectly produce value to people. These can include specific species, minerals, and ecological communities, as well as natural processes and functions. Understanding how these stocks and the ecosystem service assets that flow from them change over time is key in assessing whether services are used sustainably and the impact land-use change may have on these.
The concept of ecosystem services has become more widespread since the publication of the United Nations Millennium Ecosystem Assessment in 2005, and Costanza et al. highlight that the widespread recognition of ecosystem services has reframed the relationship between humans and the rest of nature. Natural capital is becoming a well-known concept in the UK across academia, business and Government. In 2012, the Natural Capital Committee was established to provide independent advice to Government on England’s natural capital. The Natural Capital Initiative, of which the BES is a founding partner, is working to bring together academia, business, and policy-making to give constructive action.
Valuations of ecosystem services must be reassessed periodically as natural capital is not a static resource, and ecosystem service values can change depending on the quality and quantity of habitats. The authors’ valuation of global ecosystem services in 1997 was $33 trillion per year. Using the same methods but with updated data, global ecosystem services in 2011 were valued at $125 trillion per year, taking into account both changes in valuation and size of biomes. Comparatively, GDP was $46.3 trillion per year in 1997 and $75.2 trillion per year in 2011.
Despite the pressures of increased global population and habitat loss, per hectare values of most habitats were higher in 2011 than 1997. The authors attribute the increase in unit values to improved techniques that give a more comprehensive overview. This just highlights the importance of revisiting estimates. Uncertainty around the unit value for habitats gives rise to the wide estimate of the loss of ecosystem services due to land use change – $4.3-$20.2 trillion per year from 1997 to 2011.
The authors highlight issues around valuation, emphasising that valuation of ecosystem services is not the same as commodification or privatisation. They also reason that as ecosystem services as often common goods, conventional markets may not be the best framework to manage them. Another issue that is considered is the fact that although ecosystem services benefit human well-being, they are only the relative contribution of natural capital to human well-being and do not flow directly. Only through interaction with other forms of capital can human well-being be achieved.
This recent paper highlights the extent to which we rely on the natural world for our goods and services. It is vital that all types of capital are used sustainably – all other types of capital are dependent on natural capital to some degree, and all types of capital interact with each other to give human well-being. The global estimates of ecosystem service loss between 1997 and 2011 show the impact of habitat loss across a range of biomes, and the consequences this has for human well-being. At a local level, these losses will have a profound impact on many parts of society. Further loss of habitat in vulnerable biomes such as tropical forest will only exacerbate these changes in ecosystem service provision.
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