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





How I feel now about climate change

10 03 2020
bleak-2-david-vogler

‘Bleak No. 2’ by David Vogler

Five years ago I was asked by a researcher at the Australia National University, Joe Duggan, how I ‘felt’ about climate change.

This was part of an original initiative that put a human face on the scientists working on elements of one of society’s greatest existential threats.

Thus, Is This How You Feel? became a massive success in terms of bringing to the world the idea that scientists are also deeply affected by what they see happening around them.

Five years later, Joe asked me and all the other scientists who participated to provide an update on how we feel.

Here’s what I wrote: Read the rest of this entry »





Unlikely the biodiversity crisis will improve any time soon

6 02 2020

hopelessAround a fortnight ago I wrote a hastily penned post about the precarious state of biodiversity — it turned out to be one of the most-read posts in ConservationBytes‘ history (nearly 22,000 views in less than two weeks).

Now, let’s examine whether this dreadful history is likely to get any better any time soon.

Even if extinction rates decline substantially over the next century, I argue that we are committed to an intensifying biodiversity extinction crisis. The aggregate footprint from the growing human population notwithstanding, we can expect decades, if not centuries, of continued extinctions from lag effects alone (extinction debts arising from previous environmental damage engendering extinctions in the future)1.

Global vegetation cover and production are also likely to decline even in the absence of continued habitat clearing — the potential benefit of higher CO2 concentrations for plant photosynthesis is more than offset by lower availability of water in the soil, heat stress, and the frequency of disturbances such as droughts2. Higher frequencies and intensities of disturbance events like catastrophic bushfire will also exacerbate extinction rates3.

However, perhaps the least-appreciated element of potential extinctions arising from climate change is that they are vastly underestimated when only considering a species’ thermal tolerance4. In fact, climate disruption-driven extinction rates could be up to ten times higher than currently predicted4 when extinction cascades are taken into account5. Read the rest of this entry »





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

Read the rest of this entry »





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.

Read the rest of this entry »





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.

Read the rest of this entry »





The Great Dying

30 09 2019

Here’s a presentation I gave earlier in the year for the Flinders University BRAVE Research and Innovation series:

There is No Plan(et) B — What you can do about Earth’s extinction emergency

Earth is currently experiencing a mass extinction brought about by, … well, … us. Species are being lost at a rate similar to when the dinosaurs disappeared. But this time, it’s not due to a massive asteroid hitting the Earth; species are being removed from the planet now because of human consumption of natural resources. Is a societal collapse imminent, and do we need to prepare for a post-collapse society rather than attempt to avoid one? Or, can we limit the severity and onset of a collapse by introducing a few changes such as removing political donations, becoming vegetarians, or by reducing the number of children one has?

Read the rest of this entry »