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The loss of biodiversity in Australia and the world could have disastrous consequences for human health, write Marion Carey, Katherine Barraclough and Ken Winkel.
For years we have seen a steady trickle of evidence about the disastrous effects of climate change on our environment and our health. Lately, this seems more like a torrent. The latest Intergovernmental Panel on Climate Change (IPCC) report confirms increasing extreme heat events have resulted in human mortality and morbidity.
Climate-related food-, water- and vector-borne diseases have also increased, as have climate-related trauma, displacement and mental ill-health.
Yet, much less is reported about the biodiversity loss that is occurring in tandem with climate change, and its equally concerning impacts on health.
Biodiversity underpins our ecosystem
Biodiversity — the variability among living organisms — includes diversity within and among species and within and between ecosystems.
It underpins a huge range of “ecosystem services” that support human life, including photosynthesis, soil fertility, waste decomposition, nutrient cycling, pest control, pollination, carbon sequestration, natural hazard protection, water purification and much more.
Australia, with a unique evolutionary history, has about 10% of the world’s biodiversity.
Biodiversity provides stability and resilience to ecosystems by buffering them against challenging and changing environmental conditions, including climate change.
Yet climate change, along with other forces of environmental degradation (pollution, alien species, overexploitation, habitat destruction and urbanisation) are accelerating the rate and magnitude of biodiversity decline. We now face dual crises of climate change and biodiversity loss.
Widespread environmental deterioration
A recent report for the federal government on the state of our environment documents continent-wide environmental deterioration, with 19% of our ecosystems showing signs of collapse.
Species extinction is predicted to increase substantially over coming decades unless radical changes are made.
Of critical importance, this report also recognises that this situation has undeniable implications for the health and wellbeing of Australians.
In our article in The Medical Journal of Australia today, we explore some of these impacts — including the impacts of biodiversity loss on our nutrition, access to clean water, infectious disease control, mental health, biomedical and genetic resources, as well as the wellbeing of First Nations Australians.
Food security
Good nutrition and food security both depend on biodiversity. Eating a diverse range of species, especially plants, is foundational to our health, while diversity of pollinating species is essential for a healthy food supply.
Close to 75% of the world’s food crops depend on pollinators, and, in turn, pollinators depend on healthy habitats including native vegetation for their survival.
However, our native vegetation and soils are in poor and deteriorating condition. Climate change-induced drought, heatwaves and storms are worsening crop quality, quantity and costs.
Protecting our water
Healthy ecosystems are critical for purifying, protecting and supplying water. We need look no further than Victoria for an example.
Water from Melbourne’s protected forested water catchments requires less treatment than water from other sources, saving millions of dollars.
However, native forest logging, which still occurs in Melbourne’s forested water catchment, leads to a loss of 15 000 megalitres of water annually, equivalent to the amount used by 250 000 people.
Inspiring innovation
Animal, plant and microbial biodiversity are important sources of unique medicinal compounds, biomaterials and models for bioinspired innovation.
For example, plant and animal poisons and venoms are rich sources of novel drugs or pro-drug molecular templates.
We can thank plants for some paralytic anaesthetic agents, and snakes for the discovery of angiotensin-converting enzyme (ACE) inhibitors and several antiplatelet drugs, for instance.
The marine environment results in intense species competition and evolution of complex defensive chemicals, so it is no surprise that compounds from a range of reef species are being explored for analgesic, anti-inflammatory, antimicrobial and antineoplastic activity.
Ziconotide, for treating severe chronic intractable pain, was derived from the venom of a cone snail, an inhabitant of coral reefs.
With ocean warming and acidification damaging our reef systems, natural pharmacies are being lost at a time when less than 10% of their estimated biodiversity has been described.
Ecosystem disturbance
Biodiversity plays a role in the regulation of pathogens, and ecosystem disturbance has significant implications for the risk of human disease emergence and re-emergence.
When we clear forests and remove natural habitat, wildlife is displaced and their behaviour is altered. In turn, this increases the likelihood of human–wildlife contact and risk of cross-species infection. The number and diversity of emerging infectious diseases has increased over time.
This has been linked to land use change from deforestation, agriculture, urbanisation and climate change.
There is evidence that behaviour changes of flying foxes due to climate and habitat destruction have led to increased Hendra virus spill-over risk in Australia.
Our own health
We need healthy ecosystems for our mental as well as our physical health. Biodiversity and blue and green spaces in nature play a key role in reducing stress and improving mood.
The health of the environment and intact biodiversity are also central to culture, identity and the wellbeing of First Nation Australians.
Despite the dire state of our ecosystems and biodiversity, and the implications for health outlined in small part here, the time is for action, not despair.
The way forward
We need to recognise the health threats posed by both climate change and biodiversity loss and that the health of humans, animals, plants, and the wider environment are interdependent.
We can encourage our policy makers to strengthen legislative protections for the environment, which have hitherto failed dismally.
A 2020 review of Australia’s chief environmental law (the Environment Protection and Biodiversity Conservation Act 1999, or EPBC Act) found it woefully inadequate.
Recommendations to improve this parlous state have included an overhaul of the EPBC Act, new national environmental standards, a national Environmental Protection Agency, a new threatened species plan, and a sufficient budget to achieve these goals.
We can use our voices as health experts to advocate for environmental protection for the sake of health.
Adequate funding for biodiversity recovery is desperately needed. We have the resources, but we need the will.
Annually, the amount required to halt Australia’s extinction crisis would be approximately one seventh of what Australian governments spend on fossil fuel subsidies currently .
For comparison, the cost of government economic responses to coronavirus disease 2019 (COVID-19), an emerging infectious disease of probable animal origin, up to May 2021, was 172 times greater.
We can get our own house in order by ensuring the health care system is environmentally sustainable and not adding to the risks of climate change and biodiversity loss.
We need to see ourselves connected to other species in the web of life rather than standing outside and above.
Only with a healthy planet can we ensure healthy people.
The authors would like to gratefully acknowledge the co-authors on our MJA article: Dr Emily Humphries, Dr Brooke Ah Shay, and Dr Yi Chao Foong.
Dr Marion Carey is a Sydney-based public health physician and medical editor.
Dr Katherine Barraclough is a Consultant Nephrologist at the Royal Melbourne Hospital.
Dr Ken Winkel is a leading toxinologist and an Associate Professor within the School of Population and Global Health at the University of Melbourne.
The statements or opinions expressed in this article reflect the views of the authors and do not necessarily represent the official policy of the AMA, the MJA or InSight+ unless so stated.
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If you would like to submit an article for consideration, send a Word version to mjainsight-editor@ampco.com.au.
The MJA perspective1 by Barraclough and colleagues draws on Australia’s State of Environment report2 (SOE) to argue that the biodiversity crisis has significant implications for human health. The SOE considers biodiversity (defined as genetic/species/ecosystem variety) within its broader assessment of nature and the environment.
Thus, while many impacts of environment/nature degradation on human health are well-known (e.g., pollutants), the added challenge is to recognise how the loss of biodiversity/variety matters for human health.
Unfortunately, the authors do not clearly address this. Their introduction highlights biodiversity decline and the extinction crisis. Then, they shift focus to the broader “environmental crisis”, highlighting aspects that do not clearly reflect biodiversity/variety. They miss the opportunity to reccomend significant biodiversity-related actions by the medical community, instead recommending (Box 3) general “environmental advocacy”, including communicating the “environmental crisis as a health crisis”.
Biodiversity, if assumed as underpinning all of nature/environment, appears indirectly. Their Box 2 presents nature’s benefits as ecosystem services, with loss of the biodiversity in ecosystems implying loss of ecological functioning and services (and corresponding health benefits).
None of these listed benefits correspond to biodiversity/variety itself. Yet, the earliest stated values of biodiversity/variety recognised that variety itself is beneficial, in maintaining options for future generations3,4. Global biodiversity conservation recently has moved beyond standard ecosystem services framing, and now better recognises the “maintenance of options” benefit of global biodiversity/variety5.
This overcomes over-focus on local nature/ecosystem values that too-commonly neglected global biodiversity values and conservation efforts3,4.
Beyond general “environmental advocacy”, the medical community can address the biodiversity crisis by highlighting how variety matters to human health. Maintenance of options includes the ongoing discovery of benefits for future generations (including medicines noted by the authors). Further, the medical community may expand society’s awareness of the scope of at-risk global biodiversity benefits. For example, the Global Microbiome Conservancy (https://microbiome.mit.edu/our-ecosystem/global-microbiome-conservancy/) notes global loss of human gut microbial biodiversity, and so loss of resilience-related maintenance of options. Biodiversity advocacy also can highlight already-achieved health benefits (e.g., already-discovered medicines), perhaps including current well-being reflecting appreciation of biodiversity/variety as a gift for well-being of future generations5.
1. Barraclough KA, et al. Why losing Australia’s biodiversity matters for human health: insights from the latest State of the Environment assessment Med J Aust 2023; doi: 10.5694/mja2.51904
2. Cresswell I, Janke T, Johnston E. Australia State of the Environment 2021. Commonwealth of Australia, 2021. https://soe.
dcceew.gov.au/ (viewed Jly 2023)
3. Faith DP, Biodiversity, The Stanford Encyclopedia of Philosophy, Zalta, E.D., Ed.; Metaphysics Research Lab, Stanford University: Stanford, CA, USA, 2021; Available online: https://plato.stanford.edu/entries/biodiversity/ (accessed on Jly 2023).
4. Faith DP, A Singular Concept of Biodiversity Remains the Best Way to Address the Plural Values of Nature in Conservation Planning. Conservation 2021; 1: 342-349. https://doi.org/10.3390/conservation1040026
5. Faith DP, Valuation and Appreciation of Biodiversity: The “Maintenance of Options” Provided by the Variety of Life. Front. Ecol. Evol. 2021, 9: 635670.
Thank you for this clear, powerful overview of the challenges we face, and the opportunities we have before us.