An eye on the past: a view to the future

29 11 2021

originally published in Brave Minds, Flinders University’s research-news publication (text by David Sly)

Clues to understanding human interactions with global ecosystems already exist. The challenge is to read them more accurately so we can design the best path forward for a world beset by species extinctions and the repercussions of global warming.

This is the puzzle being solved by Professor Corey Bradshaw, head of the Global Ecology Lab at Flinders University. By developing complex computer modelling and steering a vast international cohort of collaborators, he is developing research that can influence environmental policy — from reconstructing the past to revealing insights of the future.

As an ecologist, he aims both to reconstruct and project how ecosystems adapt, how they are maintained, and how they change. Human intervention is pivotal to this understanding, so Professor Bradshaw casts his gaze back to when humans first entered a landscape – and this has helped construct an entirely fresh view of how Aboriginal people first came to Australia, up to 75,000 years ago.

Two recent papers he co-authored — ‘Stochastic models support rapid peopling of Late Pleistocene Sahul‘, published in Nature Communications, and ‘Landscape rules predict optimal super-highways for the first peopling of Sahul‘ published in Nature Human Behaviour — showed where, how and when Indigenous Australians first settled in Sahul, which is the combined mega-continent that joined Australia with New Guinea in the Pleistocene era, when sea levels were lower than today.

Professor Bradshaw and colleagues identified and tested more than 125 billion possible pathways using rigorous computational analysis in the largest movement-simulation project ever attempted, with the pathways compared to the oldest known archaeological sites as a means of distinguishing the most likely routes.

The study revealed that the first Indigenous people not only survived but thrived in harsh environments, providing further evidence of the capacity and resilience of the ancestors of Indigenous people, and suggests large, well-organised groups were able to navigate tough terrain.

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Avoiding a ghastly future — The Science Show

1 10 2021

Just thought I’d share the audio of an interview I did with the famous Robyn Williams of ABC Radio National‘s The Science Show.

I’d be surprised if any Australians with even a passing interest in science could claim not to have listened to the Science Show before, and I suspect a fair mob of people overseas would be in the same boat.

It was a real privilege to talk with Robyn about our work on the ghastly future, and as always, the production value is outstanding.

Thank you, Robyn and the ABC.

Listen below, or link to the interview directly.

It’s a tough time for young conservation scientists

24 08 2021

Sure, it’s a tough time for everyone, isn’t it? But it’s a lot worse for the already disadvantaged, and it’s only going to go downhill from here. I suppose that most people who read this blog can certainly think of myriad ways they are, in fact, still privileged and very fortunate (I know that I am).

Nonetheless, quite a few of us I suspect are rather ground down by the onslaught of bad news, some of which I’ve been responsible for perpetuating myself. Add lock downs, dwindling job security, and the prospect of dying tragically due to lung infection, many have become exasperated.

I once wrote that being a conservation scientist is a particularly depressing job, because in our case, knowledge is a source of despair. But as I’ve shifted my focus from ‘preventing disaster’ to trying to lessen the degree of future shittyness, I find it easier to get out of bed in the morning.

What can we do in addition to shifting our focus to making the future a little less shitty than it could otherwise be? I have a few tips that you might find useful:

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Cartoon guide to biodiversity loss LXVII

13 08 2021

Here is the fourth set of biodiversity cartoons for 2021. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.

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Is the IPCC finally catching up with the true severity of climate change?

24 06 2021

I’m not in any way formally involved in either the IPCC or IPBES, although I’ve been involved indirectly in analysing many elements of both the language of the reports and the science underlying their predictions.

Today, The Guardian reported that a leaked copy of an IPCC report scheduled for release soon indicated that, well, the climate-change situation is in fact worse than has been previously reported in IPCC documents.

If you’re a biologist, climatologist, or otherwise-informed person, this won’t come as much of a surprise. Why? Well, the latest report finally recognises that the biosphere is not just some big balloon that slowly inflates or deflates with the whims of long-term climate variation. Instead, climate records over millions of years show that the global climate can and often does shift rapidly between different states.

This is the concept of ‘tipping points’.

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Cartoon guide to biodiversity loss LXVI

29 05 2021

Here is the third set of biodiversity cartoons for 2021. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.

Read the rest of this entry »

Worried about Earth’s future? Well, the outlook is worse than even scientists can grasp

14 01 2021

Daniel Mariuz/AAP

Corey J. A. Bradshaw, Flinders University; Daniel T. Blumstein, University of California, Los Angeles, and Paul Ehrlich, Stanford University

Anyone with even a passing interest in the global environment knows all is not well. But just how bad is the situation? Our new paper shows the outlook for life on Earth is more dire than is generally understood.

The research published today reviews more than 150 studies to produce a stark summary of the state of the natural world. We outline the likely future trends in biodiversity decline, mass extinction, climate disruption and planetary toxification. We clarify the gravity of the human predicament and provide a timely snapshot of the crises that must be addressed now.

The problems, all tied to human consumption and population growth, will almost certainly worsen over coming decades. The damage will be felt for centuries and threatens the survival of all species, including our own.

Our paper was authored by 17 leading scientists, including those from Flinders University, Stanford University and the University of California, Los Angeles. Our message might not be popular, and indeed is frightening. But scientists must be candid and accurate if humanity is to understand the enormity of the challenges we face.

Girl in breathing mask attached ot plant in container

Humanity must come to terms with the future we and future generations face. Shutterstock

Getting to grips with the problem

First, we reviewed the extent to which experts grasp the scale of the threats to the biosphere and its lifeforms, including humanity. Alarmingly, the research shows future environmental conditions will be far more dangerous than experts currently believe. Read the rest of this entry »

Time for a ‘cold shower’ about our ability to avoid a ghastly future

13 01 2021

I wish it need not have happened in my time,” said Frodo. “So do I,’ said Gandalf, “and so do all who live to see such times. But that is not for them to decide. All we have to decide is what to do with the time that is given us.”

Frodo Baggins and Gandalf, The Fellowship of the Ring

Today, 16 high-profile scientists and I published what I describe as a ‘cold shower’ about society’s capacity to avoid a ghastly future of warfare, disease, inequality, persecution, extinction, and suffering.

And it goes way beyond just the plight of biodiversity.

No one who knows me well would mistake me for an optimist, try as I might to use my colleagues’ and my research for good. Instead, I like to describe myself as a ‘realist’. However, this latest paper has made even my gloomier past outputs look downright hopeful.

And before being accused of sensationalism, let me make one thing abundantly clear — I sincerely hope that what we describe in this paper does not come to pass. Not even I am that masochistic.

I am also supportive of every attempt to make the world a better place, to sing about our successes, regroup effectively from our failures, and maintain hope in spite of evidence to the contrary.

But failing to acknowledge the magnitude and the gravity of the problems facing us is not just naïve, it is positively dangerous and potentially fatal.

It is this reason alone that prompted us to write our new paper “Underestimating the challenges of
avoiding a ghastly future
” just published in the new journal, Frontiers in Conservation Science.

Read the rest of this entry »

Influential conservation papers of 2020

19 12 2020

Following my late-December tradition, I present — in no particular order — a retrospective list of the ‘top’ 20 influential papers of 2020 as assessed by experts in Faculty Opinions (formerly known as F1000). See previous years’ lists here: 201920182017201620152014, and 2013.

Life in fluctuating environments — “… it tackles a fundamental problem of bio-ecology (how living beings cope with the fluctuations of the environment) with a narrative that does not make use of the cumbersome formulas and complicated graphs that so often decorate articles of this kind. Instead, the narrative and the illustrations are user-friendly and easy to understand, while being highly informative.

Forest carbon sink neutralized by pervasive growth-lifespan trade-offs — “… deals with a key process in the global carbon cycle: whether climate change (CC) is enhancing the natural sink capacity of ecosystems or not.

Bending the curve of terrestrial biodiversity needs an integrated strategy — “… explores different scenarios about the consequences of habitat conversion on terrestrial biodiversity.

Rebuilding marine life — “The logic is: leave nature alone, and it will come back. Not necessarily as it was before, but it will come back.

Towards a taxonomically unbiased European Union biodiversity strategy for 2030 — “… states that the emperor has no clothes, providing an estimate of the money dedicated to biodiversity conservation (a lot of money) and then stating that the bulk of biodiversity remains unstudied and unprotected, while efforts are biased towards just a few “popular” species.

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Grand Challenges in Global Biodiversity Threats

8 10 2020

Last week I mentioned that the new journal Frontiers in Conservation Science is now open for business. As promised, I wrote a short article outlining our vision for the Global Biodiversity Threats section of the journal. It’s open-access, of course, so I’m also copying here on

Most conservation research and its applications tend to happen most frequently at reasonably fine spatial and temporal scales — for example, mesocosm experiments, single-species population viability analyses, recovery plans, patch-level restoration approaches, site-specific biodiversity surveys, et cetera. Yet, at the other end of the scale spectrum, there have been many overviews of biodiversity loss and degradation, accompanied by the development of multinational policy recommendations to encourage more sustainable decision making at lower levels of sovereign governance (e.g., national, subnational).

Yet truly global research in conservation science is fact comparatively rare, as poignantly demonstrated by the debates surrounding the evidence for and measurement of planetary tipping points (Barnosky et al., 2012; Brook et al., 2013; Lenton, 2013). Apart from the planetary scale of human-driven disruption to Earth’s climate system (Lenton, 2011), both scientific evidence and policy levers tend to be applied most often at finer, more tractable research and administrative scales. But as the massive ecological footprint of humanity has grown exponentially over the last century (, robust, truly global-scale evidence of our damage to the biosphere is now starting to emerge (Díaz et al., 2019). Consequently, our responses to these planet-wide phenomena must also become more global in scope.

Conservation scientists are adept at chronicling patterns and trends — from the thousands of vertebrate surveys indicating an average reduction of 68% in the numbers of individuals in populations since the 1970s (WWF, 2020), to global estimates of modern extinction rates (Ceballos and Ehrlich, 2002; Pimm et al., 2014; Ceballos et al., 2015; Ceballos et al., 2017), future models of co-extinction cascades (Strona and Bradshaw, 2018), the negative consequences of invasive species across the planet (Simberloff et al., 2013; Diagne et al., 2020), discussions surrounding the evidence for the collapse of insect populations (Goulson, 2019; Komonen et al., 2019; Sánchez-Bayo and Wyckhuys, 2019; Cardoso et al., 2020; Crossley et al., 2020), the threats to soil biodiversity (Orgiazzi et al., 2016), and the ubiquity of plastic pollution (Beaumont et al., 2019) and other toxic substances (Cribb, 2014), to name only some of the major themes in global conservation. 

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Australia: the world’s unsustainable ‘mine’

16 09 2020

The COVID-19 pandemic has finally woken a few people up in this country. The closure of our automotive industry, the volatility of the mining sector, the deteriorating relations with our largest trading partner (China) — all these have seem to have acted like smelling salts for our semi-conscious leaders.

Australia has an abysmal manufacturing capacity, and I know that trying to fix this is very much on the table now at the highest levels. Australia is for the most part a 7.7 million km2 ‘mine’ to the world — we of course dig up our minerals and ship them overseas, and we export shit-tonnes of coal.

But much of our agricultural produce goes overseas too, including the very poorly valued live-export industry that takes the little water and minerals already in Australian soils and turns them inefficiently into livestock that is then sold overseas whole and living. Even putting aside the woeful animal-welfare issues this entails, it’s not much of a value-add and really a poor business model.

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The only constant is change

27 07 2020

I just wrote a piece for the Flinders University alumnus magazine — Encounter — and I thought I’d share it here.


As an ecologist concerned with how life changes and adapts to the vagaries of climate and pervasive biological shuffling, ‘constant change’ is more than just a mantra — it is, in fact, the mathematical foundation of our entire discipline.

But if change is inevitable, how can we ensure it is in the right direction?

Take climate change for example. Since the Earth first formed it has experienced abrupt climate shifts many times, both to the detriment of most species in existence at any given time, and to the advantage of those species evolving from the ashes.

For more than 3.5 billion years, species have evolved and gone extinct, such that more than 99% of all species that have ever existed are now confined, permanently, to the vaults of the past.

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A brief history of environmentalism in Australia since European invasion

29 06 2020

A (heavily) modified and updated excerpt from our 2015 book Killing the Koala and Poisoning the Prairie

The Australian awakening to its environmental dilemmas was a little more sluggish than elsewhere in the New World. Not only did Europeans arrive in Australia en masse only about 250 years ago, they had a more limited view of their new landscape, and were, at least initially, constrained by the harshness of their new home. Those mostly British settlers brought with them the fully formed ideas of development and progress shaped by centuries of land use in the Motherland. That ideal of conquering wilderness and transforming it into the bucolic landscape typical of the English countryside was their driving force.

The early settlers viewed the Australian bush as ugly and monotonous, features that could only be overcome by human occupation and cultivation. This neo-classical view, homesickness and the Romantic desire to transform their homes and farms into an image of those from their homeland, were defining forces in early Australian history. Unlike in Europe, though, where there were cultural taboos associated with forest degradation — bound in mysticism, spirituality, folklore and politics — no such restrictions applied to the unfamiliar Australian bush.

In fact, the Australian government passed the Crown Lands Alienation Act in 1861, which was designed to ‘open up’ the colony to settlement, and penalized landholders for not clearing the land (via a forfeit of the land back to the Crown). That single Act guaranteed the deforestation wave would continue for over a 100 years. That, and the persistent desire to make the new land look as much as possible as the old, has ensured that continuing demise of Australia’s biodiversity.

Figure 3.3-Clearing for Agriculture

Clearing for agriculture in early settlement. Anonymous, Government Farm at Castle Hill, circa 1803. Watercolour, 24×35 cm. Permission to reproduce courtesy of the Mitchell Library, State Library of New South Wales

Interestingly, clashes over land use between the settlers and Indigenous peoples were probably some of the first demonstrations of what today we would call ‘environmentalism’ in Australia. Aboriginal nations were intent on preserving their way of life (and indeed, their lives) in the face of the settlers’ onslaught. But this was seen, at most, as a mild inconvenience for the new Australians who in response invoked the idea of terra nullius — that no one owned the land, making it available to anyone (white) who wished to ‘improve’ (clear) it. Read the rest of this entry »

Extinction Anxiety

21 05 2020

Earlier this week, the SBS show The Feed did a short segment called ‘Extinction Anxiety’ where I talked with host Alice Matthews about biodiversity extinctions. Given that it has so far only been available in Australia, I made a copy here for others to view.

For more information on the state of global biodiversity, see this previous post.



CJA Bradshaw

In pursuit of an ecological resilience in the Anthropocene

3 03 2020

Changing TidesAn excerpt from Alejandro Frid‘s new book, Changing Tides: An Ecologist’s Journey to Make Peace with the Anthropocene (published first in Sierra, with photos courtesy of New Society Publishers)

The birth of my daughter, in 2004, thrust upon me a dual task: to be scientifically realistic about all the difficult changes that are here to stay, while staying humanly optimistic about the better things that we still have.

By the time my daughter turned eleven, I had jettisoned my nos­talgia for the Earth I was born into in the mid-196os—a planet that, of course, was an ecological shadow of Earth 100 years before, which in turn was an ecological shadow of an earlier Earth. The pragmatist in me had embraced the Anthropocene, in which humans dominate all biophysical processes, and I ended up feeling genuinely good about some of the possible futures in which my daughter’s generation might grow old.

It was a choice to engage in a tough situation. An acknowledgement of rapid and uninvited change. A reaffirmed commitment to everything I have learned, and continue to learn, as an ecologist working with Indigenous people on marine conservation. Fundamental to this perspective is the notion of resilience: the ability of someone or something—a culture, an ecosystem, an economy, a person—to absorb shocks yet still maintain their essence.

But what is essence? Read the rest of this entry »

The state of global biodiversity — it’s worse than you probably think

24 01 2020

Chefurka biomass slide

I often find myself in a position explaining to non-professionals just how bad the state of global biodiversity really is. It turns out too that even quite a few ecologists seem to lack an appreciation of the sheer magnitude of damage we’ve done to the planet.

The loss of biodiversity that has occurred over the course of our species’ time on Earth is staggering. This loss is now truly planetary in scale and caused by human actions, albeit the severity of which is unequally distributed across the globe1. While Sandra Díaz and company recently summarised the the extent of the biodiversity crisis unfolding1 well in their recent synopsis of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)2 report, I’m going to repeat some of the salient summary statements here, and add a few others. Read the rest of this entry »

Influential conservation ecology papers of 2019

24 12 2019

Bradshaw-Waves breaking on rocks Macquarie Island
As I’ve done for the last six years, I am publishing a retrospective list of the ‘top’ 20 influential papers of 2019 as assessed by experts in F1000 Prime (in no particular order). See previous years’ lists here: 20182017, 20162015, 2014, and 2013.

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What is a ‘mass extinction’ and are we in one now?

13 11 2019

(reproduced from The Conversation)

For more than 3.5 billion years, living organisms have thrived, multiplied and diversified to occupy every ecosystem on Earth. The flip side to this explosion of new species is that species extinctions have also always been part of the evolutionary life cycle.

But these two processes are not always in step. When the loss of species rapidly outpaces the formation of new species, this balance can be tipped enough to elicit what are known as “mass extinction” events.

Read more: Climate change is killing off Earth’s little creatures

A mass extinction is usually defined as a loss of about three quarters of all species in existence across the entire Earth over a “short” geological period of time. Given the vast amount of time since life first evolved on the planet, “short” is defined as anything less than 2.8 million years.

Since at least the Cambrian period that began around 540 million years ago when the diversity of life first exploded into a vast array of forms, only five extinction events have definitively met these mass-extinction criteria.

These so-called “Big Five” have become part of the scientific benchmark to determine whether human beings have today created the conditions for a sixth mass extinction.

An ammonite fossil found on the Jurassic Coast in Devon. The fossil record can help us estimate prehistoric extinction rates. Corey Bradshaw, Author provided

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The politics of environmental destruction

22 10 2019

C_SE 409521698 Paul Ehrlich Lecture Event - Eventbrite2

You’d think I’d get tired of this, wouldn’t you? Alas, the fight does wear me down, but I must persist.

My good friend and colleague, the legendary Professor Paul Ehrlich of Stanford University, as well as his equally legendary wife, Anne, will be joining us in Adelaide for a brief visit during their annual southern migration.

Apart from just catching up over a few good bottles of wine (oh, do those two enjoy fine wines!), we have the immense privilege of having Paul appear at two events while he’s in town.

I’m really only going to be talking about the second of the two events (the first is a Science Meets Parliament gig with me and many others at the South Australia Parliament on 12 November): a grand, public lecture and Q&A session held at Flinders University on Wednesday, 13 November.

Haven’t heard of Paul? Where have you been hiding? If by some miracle you haven’t, here’s a brief bio:

Paul Ehrlich is Bing Professor of Population Studies Emeritus, President of the Center for Conservation Biology, Department of Biology, Stanford University and Adjunct Professor, University of Technology, Sydney. He does research in population biology (includes ecology, evolutionary biology, behavior, and human ecology and cultural evolution). Ehrlich has carried out field, laboratory and theoretical research on a wide array of problems ranging from the dynamics and genetics of insect populations, studies of the ecological and evolutionary interactions of plants and herbivores, and the behavioral ecology of birds and reef fishes, to experimental studies of the effects of crowding on human beings and studies of cultural evolution, especially the evolution of norms. He is President of the Millennium Alliance for Humanity and the Biosphere and is author and coauthor of more than 1100 scientific papers and articles in the popular press and over 40 books. He is best known to his efforts to alert the public to the many intertwined drivers that are pushing humanity toward a collapse of civilization – especially overpopulation, overconsumption by the rich, and lack of economic, racial, and gender equity. Ehrlich is a Fellow of the American Academy of Arts and Sciences, the American Entomological Society and the Beijer Institute of Ecological Economics, and a member of the United States National Academy of Sciences and the American Philosophical Society.  He is a Foreign Member of the Royal Society, an Honorary Member of the British Ecological Society and an Honorary Fellow of the Royal Entomological Society.  Among his many other honours are the Royal Swedish Academy of Sciences, Crafoord Prize in Population Biology and the Conservation of Biological Diversity (an explicit replacement for the Nobel Prize); a MacArthur Prize Fellowship; the Volvo Environment Prize; UNEP Sasakawa Environment Prize; the Heinz Award for the Environment; the Tyler Prize for Environmental Achievement; the Heineken Prize for Environmental Sciences; the Blue Planet Prize;  the Eminent Ecologist award of the Ecological Society of America, the Margalef Prize in Ecology and Environmental Sciences, and the BBVA Frontiers of Knowledge Award in Ecology and Conservation Biology. Prof Ehrlich has appeared as a guest on more than 1000 TV and radio programs; he also was a correspondent for NBC News. He has given many hundreds of public lectures in the past 50 years.

I hope your jaw just dropped.

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Environmental damage kills children

1 10 2019

Yes, childrenairpollutionit’s a provocative title, I agree. But then again, it’s true.

But I don’t just mean in the most obvious ways. We already have good data showing that lack of access to clean water and sanitation kills children (especially in developing nations), that air pollution is a nasty killer of young children in particular, and now even climate change is starting to take its toll.

These aspects of child health aren’t very controversial, but when we talk about the larger suite of indicators of environmental ‘damage’, such as deforestation rates, species extinctions, and the overall reduction of ecosystem services, the empirical links to human health, and to children in particular, are far rarer.

This is why I’m proud to report the publication today of a paper on which I and team of wonderful collaborators (Sally Otto, Zia Mehrabi, Alicia Annamalay, Sam Heft-Neal, Zach Wagner, and Peter Le Souëf) have worked for several years.

I won’t lie — the path to publishing this paper was long and hard, I think mainly because it traversed so many different disciplines. But we persevered and today published the paper entitled ‘Testing the socioeconomic and environmental determinants of better child-health outcomes in Africa: a cross-sectional study among nations* in the journal BMJ Open.

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