Climate explained: humans have dealt with plenty of climate variability

23 09 2020
© Professor John Long, Flinders University, Author provided


(originally published on The Conversation)


 

How much climate variability have humans dealt with since we evolved and since we started settling (Neolithic times)? How important was migration to human survival during these periods?

 

The climate always fluctuates as variation in the Sun’s heat reaching Earth drives glacial-interglacial cycles. Over the past 420,000 years there have been at least four major transitions between ice ages and relatively warmer interglacial periods.

Modern humans emigrated from Africa to populate the rest of the globe between 120,000 and 80,000 years ago, which means our species has had to adapt to many massive climate transitions.

 

Warming and cooling

The Last Interglacial 129,000–116,000 years ago was a period of intense global warming (from around 2 ℃ higher than today to as much as 11 ℃ higher in the Arctic), leading to a large reduction of the Arctic, Greenland and Antarctic ice sheets, and a 6–9 m rise in sea level.

The front of a glacier breaking away and falling into the sea.
Arctic glaciers have melted before. Flickr/Kimberly Vardeman, CC BY

The Last Glacial Maximum from 26,500–19,000 years ago coincided with a large drop in atmospheric CO₂ and a 4.3 ℃ cooling globally.


Read more: Climate explained: will the tropics eventually become uninhabitable?


 

Low temperatures turned much of the world’s water into ice and expanded glaciers.

Read the rest of this entry »




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.

Read the rest of this entry »




Cartoon guide to biodiversity loss LXII

2 09 2020

The fifth set of biodiversity cartoons for 2020. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


Read the rest of this entry »





How much is that iguana in the window?

25 08 2020

In our latest study, we examine the downstream effects of publicising an elevated species description for a reptile that is highly prized in the international commercial wildlife trade.

We describe how iguanas from an insular population of the common green iguana (Iguana iguana) entered commercial trade shortly after an announcement was made indicating that the population would be described as a new species.

The international commercial wildlife trade presents a known risk factor for wild populations of threatened species. One organisation in particular regulates the international trade in species — the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Although most people probably know about the illegal practices involving iconic elephants and rhinos, reptiles are also targeted and traded. For example, after its discovery and description in 2016, and even though locality data were safeguarded, China’s endemic Mountain spiny crocodile newt (Echinotriton maxiquadratus) quickly entered the trade. This put conservation pressure on this small-range species (1, 2). Therefore, CITES signatory countries placed this species on its Appendix II in 2019, which lists animals and plants in need of protection.  

Read the rest of this entry »




Error-free genetic repositories: case of amphibians

18 08 2020

In our new study, we curated > 39,000 amphibian mitochondrial DNA (mtDNA) sequences from GenBank, identified > 2,000 sequencing and taxonomic errors, and published the quality-checked records as a curated dataset with an automated workflow in R. High-quality genetic data should help quantify and protect the diversity of the most threatened vertebrate group on Earth.

frogs

Upper left: species of Boophis from Andasibe, Madagascar. Upper right: Dendropsophus anceps from State of Rio de Janeiro, Brazil. Lower left; Dendropsophus bipunctatus from State of Rio de Janeiro, Brazil. Lower right: Bufo bufo from Gelderland, The Netherlands. All images from the author.

Scientists from a broad range of biological disciplines use genetic information like DNA sequences to test ecological and evolutionary hypotheses. Critically, genetics are today essential for naming species and therefore quantifying biodiversity, as well as determining where species live and how many individuals of a species occur in the wild.

Researchers are routinely asked, and more recently frequently required, by scientific journals to submit their DNA sequences to GenBank (among other public repositories of genetic data) as a requirement for publishing a paper. Although GenBank provides some quality controls (e.g., to filter sequences with bacterial contaminants and those from other kingdoms), authors are responsible for the quality of their genetic data and have full freedom to assign these to species in the taxonomy database of GenBank. Notably, once sequences have been deposited in GenBank, records are rarely updated in light of identified errors often resulting from taxonomic progress.

Two important notions emerge from the former status quo: Read the rest of this entry »





Many animals won’t cope with climate change without access to ample drinking water

12 08 2020

Climate change implies change in temperature and water, and both factors shape species’ tolerances to thermal stress. In our latest article, we show that lack of drinking water maximises differences in tolerance to high temperatures among populations of Iberian lizard species.

drinking

Climate change is a multidimensional phenomenon comprising temporal and spatial shifts in both temperature and precipitation (1). How we perceive climate change depends on whether we measure it as shift in (i) mean conditions (e.g., the mean air temperature or rainfall over a decade within a given territory), (ii) magnitude or frequency of extreme conditions (e.g., the frequency of floods or tornados or the number of days with temperatures or rainfall above or below a given threshold), or (iii) speed at which mean or extreme conditions change in space and/or time.

In aquatic ecosystems, climate change further alters water acidity, oxygen dissolution and melting of ice. However, many people, including some scientists, tend to equate climate change erroneously with increased mean temperatures. Psychologists have made the semantic point that the use of the expressions climate change and global warming as synonyms can give mixed messages to politicians, and society in general, about how serious and complex the climate emergency we are facing really is (2, 3) — see NASA’s simple-worded account on the subject here.

In our latest article (4), we reviewed the ecological literature to determine to what extent ecologists investigating the tolerance of terrestrial animals to high temperatures have looked at thermal effects over water effects. It turns out, they were five times more likely to examine temperature over water.

cb_BAAE_WaterLizardsNetwork

Frequency of correlations between climate (air temperature versus precipitation) and tolerance to high temperature of terrestrial fauna in 64 papers published in the ecological literature (thickest link = 36, thinnest link = 2) following a systematic literature review in Scopus (4).

This is counterintuitive. Just imagine you have been walking under the sun for several hours on one of those dog days of summer, and you are offered to choose between a sunshade or a bottle of water. I’d bet you’d choose the bottle of water.

Read the rest of this entry »





Double standards: climate change vs. COVID-19

3 08 2020

Both anthropogenic climate change and the coronavirus pandemic entail serious health risks. Why then do climatologists lack the public credibility and political repercussions that doctors have? Preventing the aggravation of the climate emergency is possible if we react to it in the same way we are reacting to the pandemic, essentially, following the advice of the scientific community.

 

We have as much uncertainty regarding the coronavirus COVID-19 that causes acute respiratory failure (SARS-CoV-2) as we do about human-made greenhouse gases causing climate change.

Both problems are currently costing (and will cost) trillions to national economies. But the main difference between the two when it comes to public perception is not economic but temporal. The virus has changed our lives in days to months whereas climate change is taking years to decades to do so. This short-termism about how we respond to the pace of an emergency has been sculped in our genes by evolution (1) and contaminates politics.

Early this year, after deriding the onset of the pandemic, many climate change-denialist leaders (the obvious picks are Trump, Bolsonaro, and Johnson [note that Johnson modified his public views on climate change when becoming UK foreign secretary in 2016]) had to swallow their own words and honour their political profession when human corpses started to pile up in their hospitals. Read the rest of this entry »





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.

encounter-2020_Page_01

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.

Read the rest of this entry »





History of species distribution models

21 07 2020

This little historical overview by recently completed undergraduate student, Sofie Costin (soon to join our lab!), nicely summarises the history, strengths, and limitations of species distribution modelling in ecology, conservation and restoration. I thought it would be an excellent resource for those who are just entering the world of species distribution models.

SDM

Of course, there is a strong association between and given species and its environment1. As such, climate and geographical factors have been often used to explain the distribution of plant and animal species around the world.

Predictive ecological models, otherwise known as ‘niche models’ or ‘species distribution models’ have become a widely used tool for the planning of conservation strategies such as pest management and translocations2-5. In short, species distribution models assess the relationship between environmental conditions and species’ occurrences, and then can estimate the spatial distribution of habitats suited to the study species outside of the sampling area3,6.

While the application of species distribution models can reduce the time and cost associated with conservation research, and conservation managers are relying increasingly on them to inform their conservation strategies4, species distribution models are by no means a one-stop solution to all conservation issues. Read the rest of this entry »





I’m nearing the end of my PhD/postdoc … What the hell am I supposed to do now?

13 07 2020

Originally published on the GE.blog.

What do you want to be when you grow up?

Elasmotherium

Unicorns, like job security, used to exist (actually, it’s an Elasmotherium)

The term ‘job security’ seems a fanciful idea to budding biologists — you may as well be studying unicorns (and no, narwhal don’t count …)! Now, you’re a fully fledged adult, your thoughts are likely filled with adult questions like ‘where will I live’ and ‘how will I scrape some money together?’. Not knowing where to go next can be very stressful.

A change in profession might help with job security, but if you’ve made it this far in biology, its highly likely that you (like me) have been obsessed with biology since early childhood, and it’s not something you’re willing to give up easily. On top of that, you now have years of research experience and skill development behind you — it would be better if that experience didn’t go to waste. How, then, can we keep funding our biology addiction? I don’t want to sound like a snake-oil salesman here, so let’s be straight-up about this: there are no easy options. But, importantly, there are options — in research, the university sector, and wider afield.

So, down to the serious business. Your options (depending on your personal preferences) are:

1. Research or bust!

In-house postdoctoral fellowships

Research bodies in Australia, including many universities, the CSIRO and the Australian Museum, offer in-house postdoctoral fellowships for early-career researchers. Applying for one of these postdocs usually involves the candidate developing a research proposal and initiating collaboration with researchers in the institute offering the fellowship. Read the rest of this entry »





Journal ranks 2019

8 07 2020

journalstack_16x9

For the last 12 years and running, I’ve been generating journal ranks based on the journal-ranking method we published several years ago. Since the Google journal h-indices were just released, here are the new 2019 ranks for: (i) 99 ecology, conservation and multidisciplinary journals, and a subset of (ii) 61 ‘ecology’ journals, (iii) 27 ‘conservation’ journals, (iv) 41 ‘sustainability’ journals (with general and energy-focussed journals included), and (v) 20 ‘marine & freshwater’ journals.

See also the previous years’ rankings (2018, 20172016201520142013, 2012, 20112010, 2009, 2008).

Read the rest of this entry »





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 »





Queer science

18 06 2020

queer scientists(Originally posted by Kathryn Venning on the GEL.blog)

Happy Pride Month to the beautiful Queers of the scientific community, and beyond!

I decided to write this post to help non-queer scientists interact respectfully with their queer colleagues. When I was researching for this post, I noted very little in the way of written material on queer issues specific to the sciences, or indeed, many statistics. It’s for this reason I decided to provide you with this little primer.

Before we begin, I would like to clarify some language used below and in the queer community.

The letters: LGBTQIA+

You have probably seen varying combinations of the letters, the most common is LGBT, and the most modern and inclusive is LGBTQIA+. So, as someone who grew up watching Sesame Street, let us pay homage to my childhood.

L is for Lesbian

G is for Gay

B is for Bisexual

T is for Transgender

Q is for Queer

I is for Intersex

A is for Asexual

+ is for anyone in-between, a combination of some, variants of others, or still working it out

How I identify

I identify as a woman and my pronouns are, she/her/hers, and I am never offended by they/them/their pronouns. Read the rest of this entry »





Successful movers responding to climate change

16 06 2020

tropical fishes range shiftsEcologists often rely on measuring certain elements of a species’ characteristics, behaviour, or morphology to determine if these — what we call ‘traits’ — give them certain capacities to exploit their natural environments. While sometimes a bit arbitrarily defined, the traits that can be measured are many indeed, and sometimes they reveal rather interesting elements of a species’ resilience in the face of environmental change.

As we know, climate change is changing the way species are distributed around the planet, for the main (and highly simplified) reason that the environments in which they’ve evolved and to which they have adapted are changing.

In the simplest case, a warming climate means that there is a higher and higher chance you’ll experience temperatures that really don’t suit you that well (think of a koala or a flying fox baking in a tree when the thermometer reads +45° in the shade). Just like you seeking those nice, air-conditioned spaces on a scorcher of a day, species like to move to where conditions are more acceptable to their particular physiologies and behaviours.

When they can’t change fast enough, they go extinct.

Ecologists use life-history traits to predict which species have the highest probability of moving to new areas in response to climate change. Most studies into this phenomenon have largely ignored that range shifts in fact occur in sequential stages: (1) the species arrives in a new place for the first time, (2) its population increases in size (and extent), and (3) it can continue to persist in the new spot. Read the rest of this entry »





Extinction cascades

3 06 2020

A recent online interview I did on the role of extinction cascades in mass extinctions:





Cartoon guide to biodiversity loss LXI

31 05 2020

The fourth set of biodiversity cartoons for 2020. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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





Never let a good crisis go to waste

11 05 2020

pandemic

First published in the Millennium Alliance for Humanity and the Biosphere Blog on 5 May 2020.

by Professor Dan Blumstein (University of California at Los Angeles), Professor Paul Ehrlich (Stanford University), and Corey Bradshaw (Flinders University)

Winston Churchill’s words have never been more important than today as we experience the society- and life-changing consequences of the COVID-19 pandemic.

The extent and severity of the disease is a result of ignoring decades of warnings by scientists about the general deterioration of humanity’s epidemiological environment, and specific warnings about confining live, wild animals in markets. The situation was made even more lethal by ignoring the warnings from epidemiologists and disease ecologists once it became clear that an imminent pandemic most likely arose from this practice. Many countries, including the United States, are still ignoring those warnings and the required actions to lessen the impact.

Accordingly, we should ask ourselves, “what else are we missing?” What other huge problems are hiding in plain sight where science could guide policy to avoid catastrophic future failures? For instance, there are two principal health threats that must be addressed immediately, and we must strike while the iron is hot.

The overuse of antibiotics in agriculture will cause widespread deaths from formerly treatable bacterial diseases because of the evolution of antibiotic resistance in microbes. The evolution of resistance is well-known, predictable, and obvious — not in retrospect, but now. By feeding antibiotics to otherwise healthy livestock, animals can be housed in higher densities and they grow faster. Read the rest of this entry »





Shifting from prevention to damage control

5 05 2020

timeBack in March this year before much of the world morphed into the weirdness that now dictates all facets of life, I wrote an update for the Is This How You Feel project led by Joe Duggan.

It was an exercise in emotional expression not necessarily grounded in empiricism. But in that particular piece, I had written the following line:

Few scientists in my field are still seriously considering avoidance of environmental collapse; instead, the dominant discourse is centred on damage control.

But is this correct? Is this how most scientists in conservation feel today? In a way, this post serves both as a rationale for my expectation, and as a question for the wider community.

My rationale for that contention is that it is undeniable that biodiversity is going down the toilet faster than even some of the most pessimistic of us could have predicted. We are without doubt within the sixth mass extinction event every experienced on the Earth for at least the last 600 million years.

Yet, there have never been more conservation biologists and practitioners. There have never been more international treaties and accords that expressly aim to protect biodiversity.

To assert that we have failed is unhelpful fatalism, yet it cannot be ignored that biodiversity’s predicament and those charged with turning around its fate are not exactly replete with successes. Read the rest of this entry »





A fairer way to rank a researcher’s relative citation performance?

23 04 2020

runningI do a lot of grant assessments for various funding agencies, including two years on the Royal Society of New Zealand’s Marsden Fund Panel (Ecology, Evolution, and Behaviour), and currently as an Australian Research Council College Expert (not to mention assessing a heap of other grant applications).

Sometimes this means I have to read hundreds of proposals made up of even more researchers, all of whom I’m meant to assess for their scientific performance over a short period of time (sometimes only within a few weeks). It’s a hard job, and I doubt very much that there’s a completely fair way to rank a researcher’s ‘performance’ quickly and efficiently.

It’s for this reason that I’ve tried to find ways to rank people in the most objective way possible. This of course does not discount reading a person’s full CV and profile, and certainly taking into consideration career breaks, opportunities, and other extenuating circumstances. But I’ve tended to do a first pass based primarily on citation indices, and then adjust those according to the extenuating circumstances.

But the ‘first pass’ part of the equation has always bothered me. We know that different fields have different rates of citation accumulation, that citations accumulate with age (including the much heralded h-index), and that there are gender (and other) biases in citations that aren’t easily corrected.

I’ve generally relied on the ‘m-index’, which is simply one’s h-index divided by the number of years one has been publishing. While this acts as a sort of age correction, it’s still unsatisfactory, essentially because I’ve noticed that it tends to penalise early career researchers in particular. I’ve tried to account for this by comparing people roughly within the same phase of career, but it’s still a subjective exercise.

I’ve recently been playing with an alternative that I think might be a way forward. Bear with me here, for it takes a bit of explaining. Read the rest of this entry »