Human population growth, refugees & environmental degradation

7 07 2017

refugeesThe global human population is now over 7.5 billion, and increasing by about 90 million each year. This means that we are predicted to exceed 9 billion people by 2050, with no peak in site this century and a world population of up to 12 billion by 2100. These staggering numbers are the result of being within the exponential phase of population growth since last century, such that some 14% of all human beings that have ever lived on the planet are still alive today. That is taking into account about the past 200,000 years, or 10,000 generations.

Of course just like the Earth’s resources, human beings are not distributed equally around the globe, nor are the population trends consistent among regions or nations. In fact, developing nations are contributing to the bulk of the global annual increase (around 89 million per year), whereas developed nations are contributing a growth of only about 1 million each year. Another demonstration of the disparity in human population distributon is that about half of all human beings live in just seven countries (China, India, USA, Indonesia, Brazil, Pakistan, Nigeria, and Bangladesh), representing just one quarter of the world’s total land area. Read the rest of this entry »





To feed or to perish in an iceless world

1 02 2017
cb_climatechange2_polarbears_photo2

Emaciated female polar bear on drift ice in Hinlopen Strait (Svalbard, Norway), in July 2015 – courtesy of Kerstin Langenberger (www.arctic-dreams.com)

Evolution has designed polar bears to move, hunt and reproduce on a frozen and dynamic habitat that wanes and grows in thickness seasonally. But the modification of the annual cycle of Arctic ice due to global warming is triggering a trophic cascade, which already links polar bears to marine birds.

Popular and epicurean gastronomy claims that the best recipes should use seasonal veggies and fruits. Once upon a time, when there were no greenhouses, international trade routes, or as much frozen and canned food, our grandparents enjoyed what was available at the time. So in some years we had plenty of cherries, while during others we might have feasted on plums. Read the rest of this entry »





Buying time

27 06 2016

farmOriginally published in the Otago Daily Times by Tom McKinlay

If we don’t act soon, the world we leave our children will be in a sorry state indeed, leading Australian scientist Prof Corey Bradshaw tells Tom McKinlay.

Prof Corey Bradshaw’s 9-year-old daughter lives what sounds an idyllic existence. On their small farm outside Adelaide in South Australia, she has her chickens and her dogs and her cats, her goats and her sheep.

She’s an only child, but is not short of attention from adults and reads voraciously.

She has big plans; there are at least 25 careers she likes the look of, that she’ll undertake simultaneously: farmer, wildlife rescuer, self-sufficient bush dweller – feeding herself by shooting arrows at fish – scientist and more.

She is optimistic about the future. As she should be. A 9-year-old girl living in Australia in 2016 should regard the sky as no limit at all.

All this I learn from her father, ecologist Prof Bradshaw, who talks of his daughter with an enthusiasm unbounded.

It is fair to assume she has picked up some of her interest in the natural world from him.

He holds the Sir Hubert Wilkins Chair of Climate Change in the School of Biological Sciences at the University of Adelaide.

And the ecologist, conservation biologist and systems modeller – with a University of Otago degree – has shared a great deal of his work with his daughter.

“She’s very much a farm kid, but because of who I am she gets to hear a lot about animal and plant systems around the world, and she’s travelled a lot with me and she’s a complete fanatic of David Attenborough,” the professor says.

So far, still so idyllic. But Prof Bradshaw’s work means he is at the forefront of alerting the world to what is not right with it.

Pollution, climate change, habitat loss, extinction.

His daughter has travelled with him to see species that might not be with us by the time she grows up.

“She’s hyper-aware of extinctions, in particular, and how climate change is contributing to that,” Prof Bradshaw says.

“I don’t pull any punches with her.”

In fact, he made her cry when she was 5 explaining climate change. She hasn’t needed to travel to know the pot is on the boil. Fires have forced the family to flee its South Australian property several times, not just at the height of summer.

One of the worst fires in the region struck in May a couple of years back.

“We were on the doorstep of winter and we had one of our worst fires in 20 years.”

So even without a scientist in the family, there are certain unavoidable truths for a child growing up in 21st-century Australia.

Prof Bradshaw is coming to Dunedin next month as part of the New Zealand International Science Festival to talk on climate change, looking at it from his daughter’s perspective. Read the rest of this entry »





Australia pisses away the little water it has

9 05 2016

cow_drinking_australia_dryWater, water nowhere, with little left to drink.

Australians are superlative natural resource wasters, but living in the driest inhabited continent on the planet, you’d think we’d be precious about our water use.

You’d be wrong.

On the contrary, Australia has a huge water footprint (defined as “the total volume of freshwater that is used to produce the goods and services consumed by the people of the nation”). For internal domestic use (i.e., not including agricultural and industrial uses, or water imported directly or within other goods), Australians use about 341000 litres per person per year (data from 1997–2001), which is six times the global average of 57000 litres per person per year (1).

Agricultural production is one of the chief consumers of freshwater around the world. For example, the global average virtual water content of rice (paddy) is 2.29 million litres/tonne produced, and for wheat it is 1.33 litres/tonne. Growing crops for biofuel in particular has a huge water footprint — depending on the crop in question, it takes an average of 1400–20000 litres of water to produce just one litre of biofuel (2). If an agricultural product comes from livestock — say, meat, leather, or wool — the water content is typically much higher because of the feed required to keep the animal alive. For example, it takes about three years to raise beef cattle to slaughtering age, with an average of 200 kg of boneless beef produced per animal. This requires about 1,300 kg of grains, 7200 kg of pasture or hay, and 31000 litres of water for drinking and cleaning. This means that the total amount of water required to produce 1 kg of beef is about 15340 litres (1). For Australia, which has over 20 million or so cattle at any one moment, the water footprint alone should at least be cause for concern the next time you tuck into a steak dinner. Read the rest of this entry »





Biowealth

24 02 2016

frogWhile I’ve blogged about this before in general terms (here and here), I thought it wise to reproduce the (open-access) chapter of the same name published in late 2013 in the unfortunately rather obscure book The Curious Country produced by the Office of the Chief Scientist of Australia. I think it deserves a little more limelight.

As I stepped off the helicopter’s pontoon and into the swamp’s chest-deep, tepid and opaque water, I experienced for the first time what it must feel like to be some other life form’s dinner. As the helicopter flittered away, the last vestiges of that protective blanket of human technological innovation flew away with it.

Two other similarly susceptible, hairless, clawless and fangless Homo sapiens and I were now in the middle of one of the Northern Territory’s largest swamps at the height of the crocodile-nesting season. We were there to collect crocodile eggs for a local crocodile farm that, ironically, has assisted the amazing recovery of the species since its near-extinction in the 1960s. Removing the commercial incentive to hunt wild crocodiles by flooding the international market with scar-free, farmed skins gave the dwindling population a chance to recover.

redwoodConservation scientists like me rejoice at these rare recoveries, while many of our fellow humans ponder why we want to encourage the proliferation of animals that can easily kill and eat us. The problem is, once people put a value on a species, it is usually consigned to one of two states. It either flourishes as do domestic crops, dogs, cats and livestock, or dwindles towards or to extinction. Consider bison, passenger pigeons, crocodiles and caviar sturgeon.

As a conservation scientist, it’s my job not only to document these declines, but to find ways to prevent them. Through careful measurement and experiments, we provide evidence to support smart policy decisions on land and in the sea. We advise on the best way to protect species in reserves, inform hunters and fishers on how to avoid over-harvesting, and demonstrate the ways in which humans benefit from maintaining healthy ecosystems. Read the rest of this entry »





Bee informed: Quick pollination facts about our most important pollinators

27 11 2015

if we die

If bees were to disappear, humans will disappear within a few years.

Albert Einstein

I find it interesting that so much is said about bees (including here on this blog), yet many of the ‘facts’ that one hears mentioned in any variety of news sources, public presentations and even scientific articles aren’t very well sourced and at times highly suspect.

For your fact-finding benefit then, I present to you some of the established facts about bees: Read the rest of this entry »





Australians: out-of-touch, urban squanderers

23 03 2015

There’s a romantic myth surrounding Australia that is pervasive both overseas and within the national psyche: this sun-scorched continent home to stoic bushmen1 that eek out a frugal, yet satisfying existence in this harsh rural land. Unfortunately that ideal is anathema to almost every Australian alive today.

While some elements of that myth do have a basis in reality – it is indeed a hot, dry, mostly inhospitable place if you count the entire land area (all 7.69 million square kilometres of it), and it does have the dubious honour of being the driest inhabited continent on Earth – most Australians live nowhere near the dry interior or the bush.

Despite our remarkably low average population density (a mere 3.09 people per square kilometre), Australia is in fact one of the most urbanised nations on the planet, with nearly 90% of its citizenry living within a major urban centre. As a result, our largely urban/suburban, latte-sipping, supermarket-shopping population has little, if any, connection to the vast landscape that surrounds its comfortable, built-up environs. There should be little wonder then that Australians are so disconnected from their own ecology, and little surprise that our elected officials (who, after all, represent the values of the majority of the citizens they purport to represent), are doing nothing to slow the rapid flushing of our environment down the toilet. Indeed, the current government is in fact actively encouraging the pace of that destruction. Read the rest of this entry »