“We are, as the former president of the Royal Society, Lord Martin Rees, insightfully put it, ‘destroying the book of life before we’ve even read it’”.
Dr George Crisp
WA Chair of Doctors for the Environment Australia
A LAMENTABLE situation echoed by major scientific organisations, journals and notably in the popular media by Sir David Attenborough.
A global tragedy in itself, but less obvious perhaps is that escalating species extinction rates and underlying drivers will increasingly affect our health.
Biological diversity, or biodiversity, is the variety of living species that constitute our planet’s ecosystems. The resilience and functioning of ecosystems and the natural services they provide, depend on species variability and their complex interrelationships.
These ecological services include the provisioning of food, fresh water and materials. Seemingly straightforward services are often far more complex. For example, it takes at least nine different species to enable an apple tree to produce fruit.
The control of local climatic conditions, pest populations and a range of diseases are regulatory ecosystem services. Forests improve air quality, affect humidity and rainfall. Wetland microorganisms detoxify water. Ecosystems provide natural barriers to transmission of diseases that otherwise ‘jump’ to new hosts and targets, as is the case with SARS, hantavirus and Ebola.
Nutrient cycling, soil formation and the prevention of erosion are examples of supportive ecosystem processes, critical to adequate food production and nutrition.
Of the medicines we prescribe each day, about a half derives from naturally occurring compounds, including common and important antimicrobials, anti-cancer drugs, statins and ACE inhibitors. Many would be difficult, if not impossible, to synthesise de novo, let alone discover or design. Many of our future medicines may be awaiting discovery in forests scheduled for clearing or imperilled coral reefs and wetlands.
These are just a few examples of why biodiversity loss has such far-reaching potential effects upon our health, economy and, ultimately, our survival.
Of great concern is the fact that species loss is now running between 100 to 1000 times the long-term natural background extinction rate and is accelerating.
It is also clear that our activities are chiefly responsible, from ongoing land clearing, deforestation and agriculture, pollution, and nitrogen cycle disruption, to ocean acidification and climate change.
As identified in the 2009 Nature paper ‘A safe operating space for humanity’, 1biodiversity loss has pervasive effects on how Earth systems function. Of the nine identified “planetary boundaries” that define a safe and habitable environment, we have already transgressed at least three, and of these biodiversity loss is the boundary that we have furthest exceeded.
Our understanding of the importance of functional biodiversity in preventing ecosystems from becoming compromised when disturbed has also improved, including the presence of ‘tipping points’, beyond which whole ecosystems collapse. Complex, self-regulating physiological systems cope with only so much before they suddenly and irreversibly decompensate.
We still have much to learn about life on Earth, but we’re informed enough to know that we cannot afford to allow this attrition of our planet’s ecosystems to continue. And when our health is threatened it becomes our responsibly as doctors to do something about it.
We can do what we have always done in such matters, advocate and agitate in our professional bodies, the wider community and the offices of political representatives, individually, or by supporting groups like ours.
Specifically we must demand an end to indiscriminate logging and the industrialisation of wilderness and marine sanctuaries. We must act on climate change.
1. Rockstrom J. Nature 2009 A Safe operating Space for Humanity
This article was published in Medical Observer on 7 October 2014 and appears under a Creative Commons licence.