Cartoon guide to biodiversity loss LXVIII

19 10 2021

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


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Citizens meet coral gardening

12 10 2021

It is possible to cultivate corals in the sea like growing a nursery of trees to restore a burned forest. Cultivated corals grow faster than wild corals and can be outplanted to increase the healthy area of damaged reefs. Incorporated in projects of citizen science and ecotourism, this activity promotes environmental awareness about coral reefs, the marine ecosystem that is both the most biodiverse and the most threatened by global change.


When I finished by undergraduate studies in the 1980s, I met several top Spanish marine biologists to prospect my first job ever in academia. In all one-to-one interviews I had, I was asked what my interests were. And when I described that I wanted to study ways of modifying impacted marine ecosystems to restore their biodiversity, a well-known professor judged that my proposition was an inviable form of jardinería marina (marine gardening) ― those words made me feel embarrassed and have remained vivid in my professional imagination since. Neither the expert nor the young researcher knew at the time that we were actually talking about ecological restoration, a discipline that was being formalised exactly then by botanists in their pledge to recover pre-European conditions for North American grasslands (1).

Aspects of coral gardening. The photos show (top) a diver scraping off (with the aid of a toothbrush) algae, sponges and parasites that compete for light and nutrients with the coral fragments under cultivation along suspended ropes (Cousin Island, Seychelles), (middle) coral outplantings in the Gulf of Eliat (Red Sea) hosting a diverse community of fish that clean off the biofouling for free (21), and (bottom) a donor colony farmed off Onna (Okinawa, Japan) (12). Photos courtesy of Luca Saponari (Cousin), Buki Rinkevich (Eliat) and Yoshimi Higa / Onna Village Fishery Cooperative.

Today, the term coral gardening encompasses the suite of methods to cultivate corals (tiny colonial jellyfish with an external skeleton and a carnivorous diet) and to outplant them into the wild to boost the growth of coral reefs following perturbations (2). In the face of the decline of coral reefs globally, due to the combination of climate change, pollution, and overfishing (3), this type of mariculture has gathered momentum in the last three decades and is currently being applied to more than 100 coral species in all the main reefs of our seas and oceans (4-6).

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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.





The very worn slur of “neo-Malthusian”

7 09 2021

After the rather astounding response to our Ghastly Future paper published in January this year (> 443,000 views and counting; 61 citations and counting), we received a Commentary that was rather critical of our article.

A Malthusian slur

We have finally published a Response to the Commentary, which is now available online (accepted version) in Frontiers in Conservation Science. Given that it is published under a Creative Commons Attribution License (CC BY), I can repost the Response here:


In their comment on our paper Underestimating the challenges of avoiding a ghastly future, Bluwstein et al.2 attempt to contravene our exposé of the enormous challenges facing the entire human population from a rapidly degrading global environment. While we broadly agree with the need for multi-disciplinary solutions, and we worry deeply about the inequality of those who pay the costs of biodiversity loss and ecological collapse, we feel obligated to correct misconceptions and incorrect statements that Bluwstein et al.2 made about our original article.

After incorrectly assuming that our message implied the existence of “one science” and a “united scientific community”, the final paragraph of their comment contradicts their own charge by calling for the scientific community to “… stand in solidarity”. Of course, there is no “one science” — we never made such a claim. Science is by its nature necessarily untidy because it is a bottom-up process driven by different individuals, cultures, perspectives, and goals. But it is solid at the core. Scientific confluence is reached by curiosity, rigorous testing of assumptions, and search for contradictions, leading to many — sometimes counter-intuitive or even conflicting — insights about how the world works. There is no one body of scientific knowledge, even though there is good chance that disagreements are eventually resolved by updated, better evidence, although perhaps too slowly. That was, in fact, a main message of our original article — that obligatory specialisation of disparate scientific fields, embedded within a highly unequal and complex socio-cultural-economic framework, reduces the capacity of society to appreciate, measure, and potentially counter the complexity of its interacting existential challenges. We agree that scientists play a role in political struggles, but we never claimed, as Bluwstein et al.2 contended, that such struggles can be “… reduced to science-led processes of positive change”. Indeed, this is exactly the reason our paper emphasized the political impotence surrounding the required responses. We obviously recognize the essential role social scientists play in creating solutions to avoid a ghastly future. Science can only provide the best available evidence that individuals and policymakers can elect to use to inform their decisions. 

We certainly recognise that there is no single policy or polity capable of addressing compounding and mounting problems, and we agree that that there is no “universal understanding of the intertwined socio-ecological challenges we face”. Bluwstein et al.2 claimed that we had suggested scientific messaging alone can “… adequately communicate to the public how socio-ecological crises should be addressed”. We did not state or imply such ideas of unilateral scientific power anywhere in our article. Indeed, the point of framing our message as pertaining to a complex adaptive system means that we cannot, and should not, work towards a single goal. Instead, humanity will be more successful tackling challenges simultaneously and from multiple perspectives, by exploiting manifold institutions, technologies, approaches, and governances to match the complexity of the predicament we are attempting to resolve.

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Climate change will also make us more stupid

31 08 2021

Most people are at least vaguely aware that climate change isn’t good for us.

Let’s consider the obvious direct health effects, like heat exhaustion and stroke, dehydration, increased inhalation of particulate matter from bushfires and other pollutant sources, greater expression of allergies, higher incidence of cardiovascular and respiratory diseases, greater injury rates, and higher probability of disease transmission from flooding events (see review here).

Let’s not forget the rising incidence of mental illness either.

Then there are the climatic events that increase the probability of dying violently like in a bushfire or a flood, getting caned in a major storm by debris, personal injury from storm surges exacerbated by rising sea levels, or dying slowly due to undernutrition from crop failures.

Some of the more indirect, yet just-as-insidious repercussions are those climate-driven events that worsen all of the above, such as increasing poverty, rising violent interactions (both individual-level and full-on warfare), loss of healthcare capability (less infrastructure, fewer doctors), and increased likelihood of becoming a refugee.


So, when someone says increased warming at the pace we’re witnessing now isn’t a problem, tell them they’re full of shit.

But wait! There’s more!

Yes, climate change will also make us more stupid. Perhaps one of the lesser-appreciated byproducts of an increasingly warmer world driven by rising greenhouse-gas concentrations is the direct effects of carbon dioxide on a variety of physiological functions.

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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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Pest plants and animals cost Australia around $25 billion a year — and it will get worse

2 08 2021
AAP

Corey J. A. Bradshaw, Flinders University and Andrew Hoskins, CSIRO

This article is republished from The Conversation under a Creative Commons licence. Read the original article.


Shamefully, Australia has one of the highest extinction rates in the world.
And the number one threat to our species is invasive or “alien” plants and animals.

But invasive species don’t just cause extinctions and biodiversity loss – they also create a serious economic burden. Our research, published today, reveals invasive species have cost the Australian economy at least A$390 billion in the last 60 years alone.

Our paper – the most detailed assessment of its type ever published in this country – also reveals feral cats are the worst invasive species in terms of total costs, followed by rabbits and fire ants.

Without urgent action, Australia will continue to lose billions of dollars every year on invasive species.

Feral cats are Australia’s costliest invasive species. Source: Adobe Stock/240188862

Huge economic burden

Invasive species are those not native to a particular ecosystem. They are introduced either by accident or on purpose and become pests.

Some costs involve direct damage to agriculture, such as insects or fungi destroying fruit. Other examples include measures to control invasive species like feral cats and cane toads, such as paying field staff and buying fuel, ammunition, traps and poisons.

Our previous research put the global cost of invasive species at A$1.7 trillion. But this is most certainly a gross underestimate because so many data are missing.


Read more:
Attack of the alien invaders: pest plants and animals leave a frightening $1.7 trillion bill


As a wealthy nation, Australia has accumulated more reliable cost data than most other regions. These costs have increased exponentially over time – up to sixfold each decade since the 1970s.

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Interval between extremely wet years increasing?

16 07 2021

The other day I was playing around with some Bureau of Meteorology data for my little patch of the Adelaide Hills (free data — how can I resist?), when I discovered an interesting trend.

Living on a little farm with a small vineyard, I’m rather keen on understanding our local weather trends. Being a scientist, I’m also rather inclined to analyse data.

My first question was given the strong warming trend here and everywhere else, plus ample evidence of changing rainfall patterns in Australia (e.g., see here, here, here, here, here), was it drying out, getting wetter, or was the seasonal pattern of rainfall in my area changing?

I first looked to see if there was any long-term trend in total annual rainfall over time. Luckily, the station records nearest my farm go all the way back to 1890:

While the red line might suggest a slight decrease since the late 19th Century, it’s no different to an intercept-only model (evidence ratio = 0.84) — no trend.

Here’s the R code to do that analysis (you can download the data here, or provide your own data in the same format):

## IMPORT MONTHLY PRECIPITATION DATA
dat <- read.table("monthlyprecipdata.csv", header=T, sep=",")

## CALCULATE ANNUAL VECTORS
precip.yr.sum <- xtabs(dat$Monthly.Precipitation.Total..millimetres. ~ dat$Year)
precip.yr.sum <- precip.yr.sum[-length(precip.yr.sum)]
year.vec <- as.numeric(names(precip.yr.sum))

## PLOT
plot(year.vec, as.numeric(precip.yr.sum), type="l", pch=19, xlab="year", ylab="annual precipitation (mm)")
fit.yr <- lm(precip.yr.sum ~ year.vec)
abline(fit.yr, lty=2, lwd=2, col="red")
abline(h=mean(as.numeric(precip.yr.sum)),lty=2, lwd=3)

## TEST FOR TREND
# functions
AICc <- function(...) {
  models <- list(...)
  num.mod <- length(models)
  AICcs <- numeric(num.mod)
  ns <- numeric(num.mod)
  ks <- numeric(num.mod)
  AICc.vec <- rep(0,num.mod)
  for (i in 1:num.mod) {
    if (length(models[[i]]$df.residual) == 0) n <- models[[i]]$dims$N else n <- length(models[[i]]$residuals)
    if (length(models[[i]]$df.residual) == 0) k <- sum(models[[i]]$dims$ncol) else k <- (length(models[[i]]$coeff))+1
    AICcs[i] <- (-2*logLik(models[[i]])) + ((2*k*n)/(n-k-1))
    ns[i] <- n
    ks[i] <- k
    AICc.vec[i] <- AICcs[i]
  }
  return(AICc.vec)
}

delta.AIC <- function(x) x - min(x) ## where x is a vector of AIC
weight.AIC <- function(x) (exp(-0.5*x))/sum(exp(-0.5*x)) ## Where x is a vector of dAIC
ch.dev <- function(x) ((( as.numeric(x$null.deviance) - as.numeric(x$deviance) )/ as.numeric(x$null.deviance))*100) ## % change in deviance, where x is glm object

linreg.ER <- function(x,y) { # where x and y are vectors of the same length; calls AICc, delta.AIC, weight.AIC functions
  fit.full <- lm(y ~ x); fit.null <- lm(y ~ 1)
  AIC.vec <- c(AICc(fit.full),AICc(fit.null))
  dAIC.vec <- delta.AIC(AIC.vec); wAIC.vec <- weight.AIC(dAIC.vec)
  ER <- wAIC.vec[1]/wAIC.vec[2]
  r.sq.adj <- as.numeric(summary(fit.full)[9])
  return(c(ER,r.sq.adj))
}

linreg.ER(year.vec, as.numeric(precip.yr.sum))
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Losing half of tropical fish species as corals disappear

30 06 2021

When snorkelling in a reef, it’s natural to think of coral colonies as a colourful scenography where fish act in a play. But what would happen to the fish if the stage went suddenly empty, as in Peter Brook’s 1971 Midsummer Night’s Dream? Would the fish still be there acting their roles without a backdrop?


This question is not novel in coral-reef science. Ecologists have often compared reef fish diversity and biomass in selected localities before and after severe events of coral mortality. Even a temporary disappearance of corals might have substantial effects on fish communities, sometimes resulting in a local disappearance of more than half of local fish species.

Considering the multiple, complex ways fish interact with — and depend on — corals, this might appear as an obvious outcome. Still, such complexity of interactions makes it difficult to predict how the loss of corals might affect fish diversity in specific contexts, let alone at the global scale.

Focusing on species-specific fish-coral associations reveals an inconsistent picture with local-scale empirical observations. When looking at the fraction of local fish diversity that strictly depends on corals for food and other more generic habitat requirements (such as shelter and reproduction), the global picture suggests that most fish diversity in reef locality might persist in the absence of corals. 

The mismatch between this result and the empirical evidence of a stronger coral dependence suggests the existence of many hidden ecological paths connecting fish to corals, and that those paths might entrap many fish species for which the association to corals is not apparent.

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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.


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Population of First Australians grew to millions, much more than previous estimates

30 04 2021

Shutterstock/Jason Benz Bennee


We know it is more than 60,000 years since the first people entered the continent of Sahul — the giant landmass that connected New Guinea, Australia and Tasmania when sea levels were lower than today.

But where the earliest people moved across the landscape, how fast they moved, and how many were involved, have been shrouded in mystery.

Our latest research, published today shows the establishment of populations in every part of this giant continent could have occurred in as little as 5,000 years. And the entire population of Sahul could have been as high as 6.4 million people.

This translates to more than 3 million people in the area that is now modern-day Australia, far more than any previous estimate.


Read more: We mapped the ‘super-highways’ the First Australians used to cross the ancient land


The first people could have entered through what is now western New Guinea or from the now-submerged Sahul Shelf off the modern-day Kimberley (or both).

But whichever the route, entire communities of people arrived, adapted to and established deep cultural connections with Country over 11 million square kilometres of land, from northwestern Sahul to Tasmania.

A map showing a much larger landmass as Australia is joined to both Tasmania and New Guinea due to lower sea levels

Map of what Australia looked like for most of the human history of the continent when sea levels were lower than today. Author provided


This equals a rate of population establishment of about 1km per year (based on a maximum straight-line distance of about 5,000km from the introduction point to the farthest point).

That’s doubly impressive when you consider the harshness of the Australian landscape in which people both survived and thrived.

Previous estimates of Indigenous population

Various attempts have been made to calculate the number of people living in Australia before European invasion. Estimates vary from 300,000 to more than 1,200,000 people. Read the rest of this entry »





No, you can’t argue the Medieval warm period is evidence that today’s climate change isn’t all that bad

23 04 2021
As this reconstructed village shows, Vikings made it as far as Newfoundland during the Medieval warm period. Wikimedia/Dylan Kereluk, CC BY-SA


Frédérik Saltré, Flinders University and Corey J. A. Bradshaw, Flinders University


What was the Medieval warm period? What caused it, and did carbon dioxide play a role?

We are living in a world that is getting warmer year by year, threatening our environment and way of life.

But what if these climate conditions were not exceptional? What if it had already happened in the past when human influences were not part of the picture?

The often mentioned Medieval warm period seems to fit the bill. This evokes the idea that if natural global warming and all its effects occurred in the past without humans causing them, then perhaps we are not responsible for this one. And it does not really matter because if we survived one in the past, then we can surely survive one now.

But it’s just not that simple.


Read more: 2,000 years of records show it’s getting hotter, faster


The Medieval climate anomaly

This Medieval period of warming, also known as the Medieval climate anomaly, was associated with an unusual temperature rise roughly between 750 and 1350 AD (the European Middle Ages). The available evidence suggests that at times, some regions experienced temperatures exceeding those recorded during the period between 1960 and 1990. Read the rest of this entry »





The biggest and slowest don’t always bite it first

13 04 2021

For many years I’ve been interested in modelling the extinction dynamics of megafauna. Apart from co-authoring a few demographically simplified (or largely demographically free) models about how megafauna species could have gone extinct, I have never really tried to capture the full nuances of long-extinct species within a fully structured demographic framework.

That is, until now.

But how do you get the life-history data of an extinct animal that was never directly measured. Surely, things like survival, reproductive output, longevity and even environmental carrying capacity are impossible to discern, and aren’t these necessary for a stage-structured demographic model?

Thylacine mum & joey. Nellie Pease & CABAH

The answer to the first part of that question “it’s possible”, and to the second, it’s “yes”. The most important bit of information we palaeo modellers need to construct something that’s ecologically plausible for an extinct species is an estimate of body mass. Thankfully, palaeontologists are very good at estimating the mass of the things they dig up (with the associated caveats, of course). From such estimates, we can reconstruct everything from equilibrium densities, maximum rate of population growth, age at first breeding, and longevity.

But it’s more complicated than that, of course. In Australia anyway, we’re largely dealing with marsupials (and some monotremes), and they have a rather different life-history mode than most placentals. We therefore have to ‘correct’ the life-history estimates derived from living placental species. Thankfully, evolutionary biologists and ecologists have ways to do that too.

The Pleistocene kangaroo Procoptodon goliah, the largest and most heavily built of the  short-faced kangaroos, was the largest and most heavily built kangaroo known. It had an  unusually short, flat face and forwardly directed 
eyes, with a single large toe on each foot  (reduced from the more normal count of four). Each forelimb had two long, clawed fingers  that would have been used to bring leafy branches within reach.

So with a battery of ecological, demographic, and evolutionary tools, we can now create reasonable stochastic-demographic models for long-gone species, like wombat-like creatures as big as cars, birds more than two metres tall, and lizards more than seven metres long that once roamed the Australian continent. 

Ancient clues, in the shape of fossils and archaeological evidence of varying quality scattered across Australia, have formed the basis of several hypotheses about the fate of megafauna that vanished during a peak about 42,000 years ago from the ancient continent of Sahul, comprising mainland Australia, Tasmania, New Guinea and neighbouring islands.

There is a growing consensus that multiple factors were at play, including climate change, the impact of people on the environment, and access to freshwater sources.

Just published in the open-access journal eLife, our latest CABAH paper applies these approaches to assess how susceptible different species were to extinction – and what it means for the survival of species today. 

Using various characteristics such as body size, weight, lifespan, survival rate, and fertility, we (Chris Johnson, John Llewelyn, Vera Weisbecker, Giovanni Strona, Frédérik Saltré & me) created population simulation models to predict the likelihood of these species surviving under different types of environmental disturbance.

Simulations included everything from increasing droughts to increasing hunting pressure to see which species of 13 extinct megafauna (genera: Diprotodon, Palorchestes, Zygomaturus, Phascolonus, Procoptodon, Sthenurus, Protemnodon, Simosthenurus, Metasthenurus, Genyornis, Thylacoleo, Thylacinus, Megalibgwilia), as well as 8 comparative species still alive today (Vombatus, Osphranter, Notamacropus, Dromaius, Alectura, Sarcophilus, Dasyurus, Tachyglossus), had the highest chances of surviving.

We compared the results to what we know about the timing of extinction for different megafauna species derived from dated fossil records. We expected to confirm that the most extinction-prone species were the first species to go extinct – but that wasn’t necessarily the case.

While we did find that slower-growing species with lower fertility, like the rhino-sized wombat relative Diprotodon, were generally more susceptible to extinction than more-fecund species like the marsupial ‘tiger’ thylacine, the relative susceptibility rank across species did not match the timing of their extinctions recorded in the fossil record.

Indeed, we found no clear relationship between a species’ inherent vulnerability to extinction — such as being slower and heavier and/or slower to reproduce — and the timing of its extinction in the fossil record.

In fact, we found that most of the living species used for comparison — such as short-beaked echidnas, emus, brush turkeys, and common wombats — were more susceptible on average than their now-extinct counterparts.

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One trillion dollars!

1 04 2021

Or thereabouts.

Let’s step back to 2015. In a former life when I was at another institution, I had the immense fortune and pleasure to spend six months on sabbatical in a little village just south of Paris working with my friend and colleague, Franck Courchamp, at Université Paris-Sud (now Université Paris-Saclay).

Sure, I felt a bit jammy living there with my daughter in a beautiful house just down the street from two mouth-watering pâtisseries and three different open marchés. We ate well. We picked mushrooms on the weekends or visited local châteaux. We went into the city and visited overwhelmingly beautiful museums at our leisure. We drank good champagne (well, I did, not my eight-year old). We had communal raclettes.

But of course, I was primarily there to do research with Franck and his lab, despite the obvious perks.

While I busied myself with several tasks while there, one of our main outputs was to put together the world’s first global database of the costs of invasive insects, which we subsequently published in 2016.

But that was only the beginning. With funding that started off the process with insects, Franck persevered and hired postdocs and took on more students to build the most comprehensive database of all invasive species ever compiled — InvaCost.

I cannot stress enough how massive an undertaking this was. It’s not simply a big list of all the cost estimates in existence, it’s also a detailed assessment of cost reliability, standardisation, and contextualisation. I’m not sure I would have had the courage to do this myself.

While the database itself has already been published, today we are pleased to announce the publication in Nature of the main results — High and rising economic costs of biological invasions worldwide — led by Christophe Diagne (one of the nicest people I’ve ever met), and co-authored by Boris Leroy, Anne-Charlotte Vaissière, Rodolphe Gozlan, David Roiz, Ivan Jarić, Jean-Michel Salles, me, and Franck Courchamp (of course).

Herein we described how the economic costs of invasive alien species accumulated since 1970 are tremendous, and that they have been steadily increasing over time.

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A perfect storm of global ineptitude

18 03 2021

Given the ‘success’ (i.e., a lot of people seem to be reading it) of our recent Ghastly Future paper, I thought it would be interesting to go back and have a look at what we wrote in our 2015 book Killing the Koala on the subject. I think you’ll find that if anything we were probably overly optimistic.

An updated digest of that material follows.


When your accountant tells you to reduce expenditure, you do it or risk bankruptcy; when your electrician tells you the wiring in your house is dodgy, you replace it or risk your family dying in an avoidable fire; when your doctor tells you your cholesterol is too high, you cut back fat intake (and/or take cholesterol-reducing drugs) or risk a heart attack.

Yet few with any real political or financial power heed the warnings of environmental scientists. It is not just a few of us either — globally, ecologists, conservation biologists and environmental scientists are united in telling the world (for decades now) that growth in population and consumption cannot go on forever. They have been united in telling us if we do not clean up our planet, our life-support systems could ultimately fail.

There are now nearly eight billion people on Earth, and median projections suggest that the population will grow to ten billion or more by the end of the century. Some analyses indicate that with present technologies, Earth could only sustainably support indefinitely some 5 billion people under best-case scenarios, but assuming similar proportions of poverty and suffering as we have today. Others imply that 5 billion could be many too many.

As a result, humanity is entering that near-perfect storm of problems driven by overpopulation, overconsumption, gross inequalities, and the use of needlessly environmentally damaging technologies. The problems include the intertwined dilemmas of loss of the biodiversity that runs human life-support systems, climate disruption, energy shortages, global toxification, alteration of critical biogeochemical cycles, shortages of water, soil, mineral resources and farmland, and increasing probability of vast epidemics (as COVID-19 poignantly exemplifies).

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Cartoon guide to biodiversity loss LXV

10 03 2021

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


Read the rest of this entry »




Citizens ask the experts in climate-change communication

7 02 2021

In the second of two consecutive interviews with climate-change experts (see the first one here), readers of the Spanish magazine Quercus have a chat with Katharine Hayhoe. Her words blend hope with the most putrid reality of economics and politics. May this interview inspire some environment-friendly changes in our daily routines and in how we see the beautiful life that surrounds us.


PhD in climate science, professor in political science and co-director of the Climate Centre at Texas Tech University (USA), Katharine Hayhoe works on climate projections and mitigation (1-3). Her prominent profile as communicator (4-6) made her one of the 100th most influential people in the world. To the left, Katharine has “A conversation on climate change” with citizens at the Lyndon Baines Johnson Presidential Library and Museum (Austin). Photo credits: Artie Limmer (portrait) & Jay Godwin (talk).


Interview done 20 October 2020

Below we italicise each question and the name of the person asking the question and cite a range of publications we deem relevant per question. For expanding on Katharyne Hayhoe’s views on climate change, see a sample of her public talks here and here, interviews here and here, and newspaper articles here and here. We love one of the titles of her newspaper articles “A thermometer is not liberal or conservative”. A spanish version of this article and interview has been published in the February 2021 issue of the magazine Quercus.


Question 1 of 4: There are extraordinarily influential people on a global scale who have a utilitarian perspective of nature, and think that climate change (be it of anthropogenic origin or not) entails advantages and opportunities to Western economies, and that we will be able to adapt whether changes are reversible or irreversible. Can we engage or use those influential people in any possible way to abate climate change? (7, 8) Iñaki García Pascual (Environmental geologist)

Hayhoe:

Climate change has some localised, short-term, specific benefits (9). One example is increased access to oil and gas resources in a melting Arctic (10). This temporarily profits oil and gas industries, provides some financial benefit to local communities in Greenland and Alaska short-term, and harms both them and everyone else in the long term. A book called Windfall by Mackenzie Funk describes who is “profiteering” from climate change, and how. 

Overall, however, climate change already harms the majority of people today. The poor, the vulnerable, and the marginalized are affected first and foremost. Since the 1960s, for example, climate change has increased the gap between the richest and poorest countries in the world by as much as 25 per cent. In 2019, UN Special Rapporteur on extreme poverty and human rights, Philip Alston, warned that climate change “threatens to undo the last 50 years” of development, global health and poverty reduction.” (11)

And while the rich may be able to temporarily “buy their way out of rising heat and hunger”, as Alston put it, the truth is that we all live on this planet, no matter how wealthy and influential we are. The air we breathe, the water we drink, the food we eat and all the resources we use come from our shared home. 

Climate change threatens the ability of our planet to support human civilisation as we know it. It is a threat multiplier, attacking our health, our economy, our resources and even our security. As climate change intensifies and economic markets crumble and refugee crises surge, even those who may temporarily benefit from a warmer world will be negatively impacted by these changes long-term.

That’s why it makes so much sense to take practical steps to limit carbon pollution now. Many of these actions also provide us with short-term benefits that can be quantified in economic terms: like energy savings through efficiency, cheaper electricity from renewables, more jobs, better public transportation, and even faster cars (like Tesla). Climate action also provides less tangible but arguably even more important benefits: cleaner air and water, better health, poverty reduction, and a host of other co-benefits that substantively move us towards meeting key UN Sustainable Development Goals.

To care about climate change, we don’t have to be a certain type of person or live in a certain place or vote a certain way: all we have to be is a human living on this planet, and we’re all that.

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Ancient bones — how old?

22 01 2021

Radiocarbon (14C) dating was developed by Nobel-Prize winning chemist Willard Libby, and has become the predominant method to build chronologies of ancient populations and species using the Quaternary fossil record. I have just published a research paper about 14C dating of fossil bone reviewing the four standard chemical pretreatments of bone collagen to avoid sample contamination and generate accurate fossil ages: gelatinization, ultrafiltration, XAD purification and hydroxyproline isolation. Hydroxyproline isolation is perceived as the most accurate pretreatment in a questionnaire survey completed by 132 experts from 25 countries, but remains costly, time-consuming and not widely available. I argue that (1) innovation is urgently required to develop affordable analytical chemistry to date low-mass samples of collagen amino acids, (2) those developments should be overseen by a certification agency, and (3) 14C users should be more conceptually involved in how (much) 14C chemistry determines dating accuracy. Across the board, scientific controversies like the timing of Quaternary extinctions need not be fuelled by inaccurate chronological data.


Megafauna bones from the Quaternary fossil record. Top: excavation of a partial skeleton of a short-faced kangaroo Procoptodon browneorum at Tight Entrance Cave (Western Australia) [1]: these bones are close to the limit of radiocarbon (14C) dating in a geological context 43000 to 49000 years old. Middle: metacarpal of the extinct horse Hippidion cf. devillei from Casa del Diablo (Peru) 14C dated at 11980 ± 100 years before present (BP) (CAMS-175039) following XAD purification of collagen gelatin [2]. Bottom: collection of skeletal remains of (mostly) red deer Cervus elaphus from El Cierro Cave (Spain) 14C dated at 15520 ± 75 years BP on ultrafiltered gelatin (OxA-27869 and OxA-27870 average) [3].


Scientists have widely been interested in the present and future state of biodiversity. Ecologists (the main audience of this blog) have also looked into the past with pioneering investigations addressing the composition of ancient forests and the origins of agriculture in layers of fossil pollen accumulated in lake sediments [4]. But it took us decades to see the fossil record as a useful tool (combining biological, geochemical and molecular techniques) to answer basic ecological questions. Some of those questions are critical for conserving today’s biodiversity [5, 6]: for example, when did human impacts on ecosystems become global or what extinct species have best tolerated past environmental change and what that means to modern species? [7].

The study of (pre)historic biological events relies one way or another on our ability to time when a certain animal, human, or plant occurred and what environmental conditions they experienced, and relies on concepts borrowed from archaeology (past human activity), palaeontology (fossils), palaeocology (species responses to past environments), and geochronology (age of fossils and/or their geological context). Among the range of chronological methods available to date biological and cultural samples [8], radiocarbon (14C) dating has become the most important for dating bones aged modern to late Quaternary (last ~ 50,000 years). Hereafter, ‘bone’ comprises antler, bone, ivory and teeth. 14C dating of bones is appealing at least for four reasons: 

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