Social, not ecological factors control our population

Social, not ecological factors control our population

Dr. Trevor Hancock

23 September 2020

699 words

In his 2016 book “The Serengeti Rules”, Sean Carroll tells us Charles Elton, the 1920s pioneering ecologist, identified four factors that  control animal numbers: predators, pathogens, parasites and food supply. Two weeks ago I likened these to the Bible’s four horsemen of the apocalypse.

Elton’s regulators are very effective. In one astonishing passage, Carroll notes that if a single E. Coli bacterium were to double every 20 minutes – the rate found in optimum conditions – it would take only two days for the weight of E.Coli to exceed the weight of the Earth – yes, just two days! Clearly, and happily for us, that does not happen, nor does it happen for all the other species – including us.

In the case of vertebrates (mammals, birds, fish, amphibians and reptiles), it seems humans are the chief cause of population reduction. Through a combination of habitat destruction, hunting or other interventions, deliberate or otherwise, we have reduced the Living Planet Index (a count of thousands of vertebrate populations around the world) by 60 percent between1970 and 2016 (the latest data available).

At the same time, we have vastly increased some vertebrates – our herds of livestock. Oxford University’s ‘Our World in Data’ reports there were almost 4 times as many pigs and goats in 2014 as there were in 1950 and more than twice as many cattle. But the 1.5 billion cattle and around 1 billion each of sheep, goats and pigs were dwarfed by the 21.4 billion chickens. Clearly, we have controlled the four horsemen for these animals, although of course we end up eating many of them.

At the same time, we have also controlled the four horsemen for ourselves. Our own population has roughly tripled, from 2.5 billion in 1950  to 7.4 billion in 2016; we are not suffering the same fate as most of our fellow vertebrates. In my previous column I explored the first three ‘horsemen’ and suggested that unless there is a major plague like the Black Death, they were unlikely to control the human population today. So how effective will be the last of Elton’s four ‘horsemen’ – food supply – in controlling the human population?

So far, food supply has more than kept pace with population growth. A 2019 report from the Intergovernmental Panel on Climate Change notes that there has been more than a 30 percent increase in the amount of food per person since 1961. But in spite of this, “an estimated 821 million people are currently undernourished”, while “2 billion adults are overweight or obese”. Clearly, we have a distribution problem, not a supply problem. But will we continue to have enough food for all? Well, it depends on whom you ask and how far out you look.

The latest 10-year outlook from the OECD and the UN’s Food and Agriculture Organization, looking out to 2029, expects food production will grow 1.4 percent annually, outpacing growth in demand, and food commodity prices will drop. This in spite of a growth in global population and growing demand for animal products in middle-income countries. The latter is offset by “a transition from animal-based protein towards alternative sources” in high-income countries, something the new Canada Food Guide supports.

But looking further out, the 2019 IPCC report has high confidence that by 2050 climate change will result in up to a 29 percent increase in cereal prices, up to “183 million additional people at risk of hunger” and growing food system disruptions.

Even so, this does not seem likely to put a major dent in human population growth. While world population continues to increase – the UN projects it will reach 11 billion in 2100 – the rate of increase has dropped “from 2.2% per year 50 years ago to 1.05% per year”, reports Max Roser in ‘Our World in Data’. Roser notes “The three major reasons are the empowerment of women (increasing access to education and increasing labour market participation), declining child mortality, and a rising cost of bringing up children (to which the decline of child labor contributed)”.

So for humans today, it is not natural factors that control our population. Instead, it seems, social factors are at work; we are limiting our population ourselves.

© Trevor Hancock, 2020

Dr. Trevor Hancock is a retired professor and senior scholar at the University of Victoria’s School of Public Health and Social Policy


And still the sheep look up

And still the sheep look up

Dr. Trevor Hancock

15 September 2020

701 words

Contemplating an orange-red noon-day sun almost obscured by the smoke clouds roiling in from America, burning to the south, brought vividly to mind The Sheep Look Up by British author John Brunner, an eerily prescient science fiction novel I read almost 50 years ago. (As I no longer can find my copy, I had to turn to Wikipedia for a refresher; fortunately it has a long and quite thorough summary.)

The ending is chilling. America has descended into environmental, social and economic chaos. And over in Ireland a woman, seeing the clouds of smoke, suggests to a visitor that they call the fire department. They would have a long way to go, he replies, “it’s from America. The wind’s blowing that way”.

The book ends with these lines from John Milton’s poem Lycidas: “The hungry sheep look up, and are not fed, But swollen with wind and the rank mist they draw, Rot inwardly, and foul contagion spread.” Brunner’s sheep, like Milton’s, are the poor, neglected by those in power and condemned to starve. But I also think an element of indifference is implied here as well as helplessness– the sheep look up, but it is not their problem – they just want to get fed, the rest does not concern them.

Well before we get to that point, Brunner – writing 50 years ago – has come uncannily close to describing current politics in America. For example, the Wikipedia entry summarises, “The right wing government is indifferent to these problems. The President, known as Prexy, can only offer snappy quotes in response to various disasters. When poisonings and famine become rampant, the government scapegoats Honduran communist rebels and puts the country under martial law. They resort to violence and oppression to silence their critics.” And there is much more in this vein.

So here are the Americans, living out many elements of John Brunner’s dystopian future. But the fires are what grab our attention right now. What is going on there? Why is America burning? In brief – climate change and, underlying that, good old-fashioned American thirst for economic growth, as well as neglect of poverty and racism; the perfect storm that Brunner foresaw, and one to which we are not immune here in Canada.

Climate change is the most prominent factor, and speaking about the massive fires in California this past week Governor Newsom is clear: “The debate is over, around climate change . . . This is a climate damn emergency. This is real and it’s happening.” What’s more, it’s happening a lot more quickly and severely than was foreseen only a few years ago.“In the last few weeks alone,” said Governor Newsome, “we’ve experienced the hottest August ever . . . arguably the hottest temperature ever worldwide, record-breaking temperature in Los Angeles”

But underlying climate change are two other key factors: Fire suppression largely to preserve valuable timber, but increasingly to protect communities as  – the second factor – people have increasingly moved into the wildland-urban interface, butting up against forests, scrub and grasslands. And underlying all that is the single-minded pursuit of short-term gain while ignoring long-term pain.

“By grazing livestock, logging the trees for timber and systematically fighting fires before they can run their course”, wrote BBC Earth reporter Claire Asher in 2016, “humans have changed the structure of the ecosystem and encouraged a build-up of forest-floor vegetation”. Then along comes climate change, which heats and dries out the air, the land and the vegetation and – bingo!

Secondly, the New York Times reported in November 2018 that “there were 12.7 million more houses and 25 million more people living in the [wildland-urban interface] zone in 2010 than in 1990” in the USA, including around one million in California. Moreover, when they burn down, they are for the most part rebuilt in the same place.

 “Crime and racial and civil unrest is growing”, wrote Brunner. “ Travel abroad is discouraged because of terrorist attacks on planes . . . The number of poor people is growing while the shrinking number of the wealthy enclose themselves in walled communities guarded by armed mercenaries.” Oh, and “and infectious disease is rampant”. And still the sheep look up, hoping for salvation.

© Trevor Hancock, 2020

The four horsemen of ecology

The four horsemen of ecology

Dr. Trevor Hancock

9 September 2020

702 words

According to the Book of Revelations in the New Testament the Four Horsemen of the Apocalypse are conquest, war, famine and death, while in the Old Testament’s Book of Ezekiel they are sword, famine, wild beasts, and pestilence or plague. (Sometimes, apparently, conquest is interpreted as pestilence or plague.)

But whatever we call them, they are remarkably close to what we might call the four horsemen of ecology, which regulate population size in nature. In his 2016 book “The Serengeti Rules”, Sean Carroll discusses the work of the pioneering ecologist Charles Elton in the 1920s. In thinking about how animal numbers are regulated to avoid over-population, “Elton suggested that, in general, increases in numbers were held in check by predators, pathogens, parasites and food supply”.

We, of course, are animals, and we are suffering a population explosion, just as lemmings and other species do. But like other animals, we are held in check – or will be – by the same four horsemen of ecology – and some others of our own making, as I will discuss next week. So let’s see how Elton’s four ecological horsemen are working out for humans on Earth today. Why are we not controlled, and what might control us?

The first control is predators, and in “The Serengeti Rules” Sean Carroll  writes: “Kill the predators and the prey run amok”. But we humans are apex predators, there is very little that preys on us, if by ‘predator’ we mean animals that hunt us to eat us. Our main predators are crocodiles (about a thousand deaths a year, according to the online World Atlas), lions (about 100), tigers and other big cats, and occasionally wolves, some sharks (about 10 each annually), and a few other species such as bears.

Animals that kill us somewhat incidentally (they are not preying on us, just protecting themselves) are much more dangerous; snakes kill about 50,000 people each year, scorpions about 3,000. Dogs are not human predators, but are important incidental killers, because in some parts of the world where rabies is widespread they bite and infect us, killing an estimated 25,000 humans annually. But true predators are hardly threats to our numbers today, and anyway – sadly – we have dramatically reduced them. 

The most important large animal that kills humans, however, is us, largely through homicide and war, although we are not truly predators. The World Health Organisation (WHO) estimated in 2014 that almost half a million people died from homicide in 2012, and another 200,000 or so directly from war in 2014, with many more dying because of the hunger and diseases that result from war.

So let’s turn to Elton’s second and third categories of pathogens and parasites. It turns out the most dangerous animals to humans are insects, and top of the list is the mosquito, which WHO reports “causes millions of deaths every year” by spreading malaria (435,000 deaths in 2015) and many other diseases.  Altogether, WHO estimates that vector-borne diseases (chiefly via insects) caused by either parasites, bacteria or viruses kill about 700,000 people  a year, and sicken hundreds of millions more.

But these are diseases that we don’t spread directly to each other, they require an intermediary. So it may be useful to distinguish diseases spread to us by other animals, (which might be considered ‘pestilence’ – diseases spread by pests) from what the Old and New Testaments call ‘plague’, by which I mean the infections we pass on to each other (even though many of them, such as Covid -19, originate in other animals).

‘Plagues’ have been and are the really big killers in the realm of pathogens. The WHO reports that 1.5 million people died from TB in 2018, while 690,000 people died from HIV-related causes in 2019. The annual influenza epidemics cause 290,000 to 650,000 respiratory deaths, while in 2018, there were more than 140,000 measles deaths globally. But nonetheless, it seems unlikely plagues will control our population, unless we get a pandemic as lethal as the Black Death.

So next week I will deal with the fourth of Elton’s controls – food supply – and the global ecological changes we are creating, as well as the social – rather than ecological – controls we have created for ourselves.

© Trevor Hancock, 2020

Stop using taxpayers’ money to fund pollution

Stop using taxpayers’ money to fund pollution

Dr. Trevor Hancock

1 September 2020

699 words

In May, The World Health Organisation (WHO) released its “Manifesto for a healthy and green COVID-19 recovery”. It is in many ways an astonishing document, because it speaks briefly and plainly to the many global problems we face and how we need to respond. But perhaps the most astonishing and heartening part is the last of its six-point prescription: “Stop using taxpayers money to fund pollution”, by which is meant “subsidizing the fossil fuels that are driving climate change and causing air pollution”

Globally, the International Energy Agency (IEA) reports, fossil fuel subsidies vary widely each year, largely based on the price of fossil fuels, reaching a peak of almost US440 billion in 2018, which was “more than double the estimated subsidies to renewables”.

In 2019 they were almost US$320 billion, with the decline “related in large part to lower average fuel prices over the course of the year”. In 2020, because of the economic impact of Covid on prices, they may fall as low as US$180 billion.

In 2019 the largest component of direct subsidies were to the oil industry (USD 150 billion), followed by electricity (USD 115 billion), natural gas (USD 50 billion) and coal (USD 2.5 billion). As a result, noted the IEA, “consumers receiving these subsidies paid on average around 85% of the competitive market reference prices for the energy products concerned”.

However, these are only direct costs. What gets overlooked – deliberately, one has to assume, since it is so obvious – are the “costs generated by health and other impacts from such pollution”. These amount to indirect or hidden subsidies, since the fossil fuel industry – like so many industries – does not carry the cost of the health, environmental and social impacts of their activities.

These costs are enormous: The WHO states: “Including the damage to health and the environment that [fossil fuels] cause brings the real value of the subsidy to over US$5 trillion per year”. The $5 trillion estimate (which amounts to about 6 percent of global GDP) comes from the International Monetary Fund. In fact, the IMF finds, “under-charging for domestic air pollution (accounted) for about half of the total subsidy and global warming about a quarter”.

These and other indirect or hidden subsidies are not reflected in the price. If they were, the IMF reported “Efficient fossil fuel pricing in 2015 would have lowered global carbon emissions by 28 percent and fossil fuel air pollution deaths by 46 percent, and increased government revenue by 3.8 percent of GDP”.

Canada is not innocent of these outrageous fossil fuel subsidies. According to the International Institute for Sustainable Development (IISD) in Winnipeg, federal subsidies to the fossil fuel industry were at least $600 million in 2019, but that “does not include tax provisions, subsidies for the Trans Mountain project, or subsidies resulting from credit support to fossil fuel producers”. Nor does it include provincial subsidies, which “also account for billions each year and, on the whole, outpace federal subsidies”.

An August 12th article in the National Observer by Barry Saxifrage & Chris Hatchused the Energy Policy Tracker developed by the IISD and its partners to examine Canada’s fossil fuel subsidies. They found that “Canada has committed nearly ten times the G20 average per capita — for a total of $12 billion so far this year in new fossil fuel support”.  They also point out that Canadian governments have only committed one-tenth as much to supporting clean energy.

Small wonder we are on track to miss not only the ambitious 1.50 C target for global warming but the 20C target of the Paris Accords. Clearly governments everywhere are either not truly understanding the situation or – since that seems unlikely – ignoring it. In doing so, they are ignoring the suffering of millions of people exposed to air pollution, and the millions more that will be harmed by climate change in the coming decades.

Clearly there is an urgent need for full cost accounting and pricing, both for the fossil fuels industry and for all other health–damaging industries. And if we are going to subsidise energy at all, let’s switch all the subsidies to clean and renewable energy and conservation, rather than continuing to pay for pollution.

© Trevor Hancock, 2020

Dr. Trevor Hancock is a retired professor and senior scholar at the University of Victoria’s School of Public Health and Social Policy