Geoff Holland – Your academic focus began with plant-based agriculture. What attracted you to become a leading researcher on farming and food plants?
Jane O’Sullivan – I had a sense that humanity was facing limits to planetary resources. I wanted to know more about that, how the food system worked, and how we could keep feeding everyone into the future. But I found agricultural science is a very production-oriented field, or was then, and it didn’t offer many openings in big-picture thinking. So, I ended up in development agriculture, hoping to improve the sustainability of resource management, underpinning the livelihoods of the rural poor.
GH – So, your attention has always been on how humanity feeds itself. How are we doing in that regard?
JO – I’d say we’re treading a very fine line. We are using essential resources like soils, freshwater, and mineral nutrients at far greater than sustainable levels. And the food system is contributing to pollution at levels that are disrupting natural systems on a planetary scale. That includes greenhouse gas emissions, nitrogen and phosphorus loads from fertilizer runoff, as well as persistent biocidal chemicals. The rate of improvement in crop yields has slowed for all of the major crops that we rely on. And we’re losing arable land to soil erosion and salinity. Some of the most important breadbasket regions of the world depend on groundwater for irrigation and are using it up much faster than it can be replenished. We also have limited supplies of mined fertilizers like phosphorus and potassium, which are coming from locations where access is threatened by geopolitical instability. That’s on the supply side. And on the demand side, an increasing number of countries depend utterly on imported food. So, they are at the mercy of international grain prices. And these prices are increasingly volatile in response to more extreme weather events and regional conflicts as we’ve seen with the Ukraine war.
It’s dangerous to try to predict when famines might occur because humanity’s shown an extraordinary capacity to muddle through and avoid catastrophic shortages. But every effort we make to squeeze another year of sufficiency out of the system makes the whole system more complex and interdependent, and therefore more brittle. When it fails, it might fail catastrophically, triggering wars. Several countries in Sub-Saharan Africa were on the brink of famine last year. I think full-blown famines are likely to return pretty soon.
One buffer we have is the grain that’s currently fed to livestock, some of which could be diverted for human use. But we have to have a way for poor countries to pay for it, and to offer a price that diverts it from feeding chickens and pigs. That probably requires a good deal of intervention by global entities to redistribute food by mandate rather than by maximizing economic returns. I don’t know if humanity can manage to achieve that.
GH – Chronic hunger is a fact of life for a billion or so out of the 8 billion humans on Earth. How does climate change figure into the dynamics of feeding all those people?
JO – Well, the science is saying climate change will be a fairly small contributor to food stress in comparison with population growth, but it’s still a huge concern. One bright spot that I see when looking at climate change scenario maps is that they expect higher rainfall in the Sahel. But the Sahel will also experience more extreme heat. So, I don’t know how that will play out for crop production.
But it always bewilders me how the same people who get passionately concerned about climate change reducing yields by 20%, can claim that doubling or quadrupling the population of African and Middle Eastern countries is not something we should be concerned about.
GH – E.O. Wilson was a powerful voice on humanity’s destruction of nature. He called for half the Earth to be set aside for restoration to its sustainable, life-giving natural state. Why is the “Half-Earth” idea such a formidable challenge?
JO – I think it’s a very ambiguous concept. It’s useful to have a clear benchmark for people to latch on to, to give an idea that humanity should leave some of the Earth for other species. But it’s no good if the half we reserve for nature is all tundra and deserts. So, it must mean that we should set aside a good share of each of the other types of habitat that other species depend on. But it becomes unworkable if you expect every type of habitat to be reserved by half: how far back in history must we go to define the original habitat type of any area? And how far into the future to allow for depopulating those areas? I really struggle with the practicality of this Half-Earth idea. If you start thinking about the detail of it, it may be unworkable.
GH – Recently, more of your attention has been focused on the impact of our Earth’s unchecked human population growth. Why has population growth become so central to your academic outreach?
JO – Population is the denominator of all our environmental challenges… the multiplier of everything else, as Bill Ryerson says. I always saw it that way, but I became increasingly concerned about the way it was brushed aside and ignored as a factor we could influence. I started looking into this because I couldn’t understand where the rationale was coming from, that seemed to be saying a hands-off approach is not only more ethical but more effective at ending population growth.
Back in the 1960s and 70s, population growth was widely seen as a threat to economic development in poor countries. That motivated a lot of government and international support for voluntary family planning programs. But during the 1980s, a new theory emerged that population growth was economically neutral. From there it was inferred that anyone who wanted to impose fertility reduction must have an ulterior motive to suppress people of color by controlling their numbers or something like that. I couldn’t find any data supporting this thesis, so I started analyzing the raw data myself. And what I found was extremely strong evidence that population growth keeps poor countries poor, supporting what the economists in the 1950s to 70s were saying. So, I tried to track down the source of the change in thinking and it all seems tied up in a campaign by the Catholic Church to defend its ban on contraception by discrediting family planning programs. Although a lot of other rights groups have attached themselves to this mission, what I see as a misplaced concern. Dr. Steven Mumford has meticulously gathered evidence on this and his website, Church and State.
So, we seem to have a sort of “state capture” of the UN going on, where it’s politically incorrect to say that population growth is harmful. While the UN is supporting women’s access to contraception, they denounce linking this in any way with population growth. So, there are no longer efforts to raise awareness of the problems exacerbated by population growth or to recommend smaller families. So, the patriarchal cultural norms remain unchallenged, and girls are raised with no expectation in life other than to raise a large group of children. Giving them access to contraception doesn’t change that. To my mind, this is a terrible betrayal of the world’s poor and a betrayal of future generations by people who claim to be defending the poor against “Malthusians.”
GH – What does a sustainable population of humans on Earth look like, and is there a way to get there thoughtfully, over an extended period, without tribalism combined with existential threats like climate change and hunger causing a massive, planetary-scale die-off of life on Earth?
JO – A sustainable human population on Earth that allows everyone to leave a good standard of living is probably only about 2 billion people. And it will take a very long time to get to that level. So, navigating that transition is going to be quite a challenge, and the chance of avoiding a significant die-off is shrinking all of the time. Maurice Strong, when he was the head of the first United Nations Earth Summit in 1992, said, “Either we reduce our numbers voluntarily or nature will do it for us brutally.” We’ve been neglecting the voluntary option for a few decades now. And we’re getting to the pointy end of things.
It’s possible we could get to 2 billion by embracing low birth rates and managing rather than resisting population decline. But in the meantime, we are so far into overshoot that we’re depleting and degrading the natural resources we need. So, it’s a race between how fast we can reduce humanity’s demands on the environment, and how fast the environment’s capacity to meet those demands is shrinking. As long as human numbers keep growing, we’re losing ground on that.
Obviously, it helps to simultaneously reduce the demands per person on the environment along with shrinking human numbers. That’s something that all developed countries need to be working very hard on. Even middle-income countries are now consuming well over a sustainable level for the planet’s current population. But we can’t get there just by reducing consumption levels per capita. We have to work on minimizing the peak human population. We need to allow it to decline without public policy working to prevent it from declining, which is what seems to be the focus of governments in developed countries at the moment.
GH – Expecting humans to accept voluntary limits to family size seems like a very tall order, especially in the world we know that’s substantially divided culturally. It doesn’t seem possible without building genuine trust across gender, ethnic, and national divides. Is there a way to build that kind of planetary-scale trust, and what would common commitment on a whole-Earth scale look like?
JO – Building global trust is a noble cause, but I don’t think it’s necessary for reducing the birth rate. What is necessary is clear messaging about people’s self-interest and the interests of their children, alongside providing good quality and culturally appropriate family planning services. There are examples of countries that succeeded in going from high fertility to low fertility in one generation, from all regions and all creeds, whether Buddhist or Muslim, Catholic or Protestant. So, I don’t think cultural diversity is a barrier.
Some people like to imagine a sort of global capitalism, where the whole planet is run by a benign global government that ensures fairness. I don’t think this is remotely feasible. It would be even more prone to state capture by the rich and powerful than the national or subnational democratic governments today. I think it’s tilting at windmills to think we can avoid overpopulation by working to build global trust. or by working to lift women’s status for that matter. What we know is that direct approaches to promote voluntary birth control work quickly. And by bringing birth rates down, they simultaneously empower women and increase their access to education and economic opportunities. Lower birth rates also powerfully boost the economic development of whole countries, which stabilizes them politically and makes them more peaceful participants in the global community of nations. So, there have never been more successful development interventions than voluntary family planning programs.
GH – Well-funded groups are retrenching behind the dominant economic players and conservative religion, who are using misinformation and denial to resist progressive public policy on existential challenges like population, climate change, and biodiversity loss. What is the answer to that?
JO – This is the biggest challenge: how to reverse state capture by financial and religious elites and wrest control of our democracies back in the interests of common people. The French economist Thomas Piketty, very nicely laid out how the accumulation of capital feeds off and impoverishes the majority. We need more public discourse challenging the neoliberal paradigm, which is designed by and for the wealthy. But what few people appreciate is that reversing population growth is a powerful way of reversing inequalities, because the economic elites depend on having surplus labor to keep workers cheap and compliant, and limited housing to extract as much as they can back from those workers in rents and mortgage payments. We really flip the dynamics when populations start to decline. I think that’s a very positive and hopeful trend for the future.
GH – At this time, about 7 out of 10 acres dedicated to agriculture on Earth are used for livestock production. Do you see a time when most of humanity will be vegetarian eaters, and how much of a difference would that make, when we’re told we need to return half of our Earth to its natural state to live sustainably?
JO – I would like to see a big drop in ruminant animals (that’s cattle, sheep, and goats) as part of the climate change mitigation effort. And I would like to see marginal range lands destocked and rewilded back to forest or natural savanna. But range lands aren’t the biggest issue. As I mentioned earlier, I think the big gain in terms of food security would be shifting cropping from fodder crops to food crops. But that mostly affects intensive animal husbandry like chickens and pig production.
I don’t think making everyone vegetarian is likely to happen. But certainly, less meat per person is going to be essential if we are to avoid catastrophic climate change and food insecurity. However, one thing to consider is that foregoing range-fed meat means relying even more heavily on synthetic nitrogen fertilizers as the basis for the protein in our diets. That’s an extra input of energy that generates more greenhouse gases. And it generates a lot of nitrous oxide in particular, which is a very powerful greenhouse gas. So, there seem to be few free lunches on environmental sustainability. Other than having fewer kids, which has no environmental downside.
GH – A lot of countries are now worried about population decline and its economic impacts. They are concerned there will be too many elderly people for pension systems to cope with and not enough workers to service them and pay taxes. How do we balance these concerns with the need for population contraction to retain environmental sustainability?
JO -The media and the growth lobby have built up a lot of anxiety about population aging. Most of it is ill-founded. In particular, the economic models that are saying the workforce will shrink are wrong. One of the big advantages of a declining population is a tight labor market, where unemployment goes down, and workforce participation goes up. So far, no aging country has seen any drop in the proportion of people working, so the tax base is not under threat. And the pension system can be sustainable if the average retirement age goes up just a bit, which it is tending to do anyway. If the media spent as much time talking about our environmental challenges as they spend talking about the challenges of aging, we would be welcoming population decline with open arms.
Another big advantage of ending population growth is that we don’t need to spend so much money and resources, building more houses and infrastructure. That immediately reduces greenhouse gases per capita, because construction is such an energy and emissions-intensive industry. We would also be spending a bit less on education since the proportion of children would be smaller. And there might be big savings on prisons because low unemployment and less income inequality tend to reduce crime rates. We would gradually regain the productivity losses due to congestion, from traffic jams to ambulance ramping at overcrowded hospital emergency rooms. And all of these savings together will go a long way towards paying for the extra pensions and health care. High population density constrains how people live. Many who live in apartments would love to have a bit more space, and maybe a garden. So gradually, more people will have these choices as populations decline. Of course, there will be adjustments to make. But there are decades in which to make them. On the whole, I think population decline will be a very positive thing.
Dr. Jane N. O’Sullivan is an Honorary Senior Research Fellow at the University of Queensland and a co-convenor of The Overpopulation Project. She has led international research on tropical subsistence and semi-subsistence farming systems, before shifting her focus to the threats posed by population growth to food security, economic development and ecological sustainability, and the efficacy of measures available to limit population growth. In this cross-disciplinary field, she has worked with ecological economists, environmental philosophers, demographers, and medical practitioners. She is also an executive member of Sustainable Population Australia and an expert adviser to the UK charity Population Matters.