People often have a poor or only partial understanding of just how great the benefits of biodiversity are for human health, and how significant they may be in future. Sustaining Life: How Human Health Depends on Biodiversity, by Eric Chivian and Aaron Bernstein, goes a long way to providing the essential information needed to support increased protection efforts.

The diversity of life on Earth – the numberless forms of plants, animals and other beings -- is the result of billions of years of evolution under turbulent conditions.  It currently is undergoing one of the biggest mass extinctions in the history of the planet. This "Anthropocene extinction" – a result of the combined assault of industrialised economies and large human populations – is killing life forms at an exceedingly rapid rate.  It comes at a price to humans as well as to the ecosystems and species we are destroying.  

The Economics of Ecosystems and Biodiversity, a recently published international study supported by the German government and written by leading international economists, puts the direct costs at some US$2 trillion to $5 trillion per year. This is considerably more than the cost to date of the current global financial crisis, but with the additional difference that it is happening every year. The estimate may be a conservative one because it does not takes full account of benefits that can be expressed readily in monetary terms.   

Currently, the biodiversity crisis shows few signs of abating. Ten leading conservationists at the World Conservation Congress -- held in Barcelona, Spain, in October 2008 -- were unanimous in concluding that the world would fail to meet its agreed target of reducing the rate of biodiversity lost by 2010.

Sustaining Life introduces the concepts of biodiversity and ecosystem services and explains how both are threatened by human activity. The book also provides fascinating accounts of medicines from nature; describes threatened groups of organisms valuable to medicine; looks at the links between ecosystem disturbance, biodiversity loss and human disease; and explores the role of biodiversity in food production. It concludes with a chapter on what individuals can do to help conserve biodiversity.

Edited by two physicians from Harvard Medical School's Center for Health and the Global Environment, the book contains contributions from more than one hundred other leading scientists and medical practitioners from around the world. It is an easily accessible work, assuming no specialist knowledge on the part of the reader. Sustaining Life  is an invaluable tool for educators, policy makers and concerned citizens everywhere.

Sustaining Life: How Human Health Depends on Biodiversity
Eric Chivian and Aaron Bernstein
Oxford University Press, 2008

 -- By Caspar Henderson