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8 billion people – the defining issue of the 21st century

In this article from his Ecosocialist Discussion website, Alan Thornett tackles the controversial question of population and argues that the left can no longer avoid the debate.

Thursday December 15th last year (2022) was the day that the human population of Planet Earth exceeded the 8 billion people mark – which is set to be the defining issue of the 21st century. As David Attenborough has commented: “All of our environmental problems become easier to solve with fewer people, and harder – and ultimately impossible – to solve with ever more people”.

For most of the 200,000 years that modern humans have been on the planet, the population was stable at about 1 billion. This changed dramatically at the end of the 18th century with onset of the industrial revolution. It then quadrupled during the 20th century – reaching 1.6 billion by 1900, 6 billion by 2,000, and then 8 billion by December 15th 2022.

For the past 50 years, the net (or absolute) annual increase in the global population has fluctuated at between 70 and 82 million, and shows little signs of reducing. The UN predicts that the global population will rise to around 11 billion by the end of the 21st century ­ which is probably beyond the carrying capacity of the planet.

There are also two additional factors that have  to be taken into account if we are to understand the full implications of population increase.

The first is that the global per capita human consumption – of food and energy for example – is increasing in parallel with the population figures. The second is what is termed ‘the total physical infrastructure’. This is a major study published in The Anthropocene Review in 2016 that measured ‘the total physical infrastructure’ – i.e. roads and buildings etc – necessary to sustain contemporary human society. This currently weighs in, they found, at a staggering 30 trillion tonnes, which is 4,000 tonnes for every human being on the planet – which presents human impact in its full perspective.

The response

The silence that greeted the 8 billion figure, however, was deafening. There was nothing from the government and very little from the media – with the honourable exception of the Guardian. The political and religious elites continued to insist that rising population numbers present no problem for the planet or its ecosystems, and imply that there are no limits to the size of the human population the planet can sustain.

It is a ridiculous proposition. How can an increase of between 70 and 82 million people a year – equivalent to the population of Germany – not have an impact on an already overstretched planet and its diminishing and finite resources?

In fact, population growth is a major factor behind most aspects of the ecological emergency we face today. These include, economic growth, carbon emissions, resource and fresh water depletion, species extinction, land and oceanic pollution driven by ever increasing quantities of industrial and human waste. It is also behind the increased risk that we face from the zoonotic crossover of dangerous pathogens from other species since the Covid19 pandemic.

Most ruling elites, of course, welcome rising population figures – even if they keep quiet about it. They see in them expanding markets, higher profits, workers for the factories and the services and soldiers for their battlefields. Rising population numbers allow them to claim that they are providing ‘record numbers’ of almost anything when per-capita figures would show a very different picture. This is facilitated by the lack of awareness on population issues in the general public.

A factor that keeps such denial alive today is the way that population figures are distorted – grossly so in some cases. We are told, for example, that since the global birth rate is falling there is not a problem. This is not true. Population figures are an equation between the birth rate and the death rate, and while the birth rate is indeed falling the death rate is falling even faster. This is producing a net (or absolute) increase of between 70 and 82 million people a year – and has been doing so for the past 50 years.

We are told that population figures are extremely complicated because birth rate varies widely and in some countries it is declining with what is called a ‘below replacement rate’. This is true. In the end, however, it is the global figure that paints the clearest picture since in the end we have only one atmosphere, one biosphere, and one planet.

The UK government routinely distorts population figures to their advantage. When challenged over the state of the NHS, for example, they say ‘there are more doctors and nurses than ever before’. When challenged about unemployment they say ‘there are more people in employment than ever before’. Well, of course there are, since the UK population has risen by over 3.5 million over the last 10 years which is three times the population of Birmingham, for example.

They are rarely challenged on this because the opposition parties share the same mind-set – i.e. don’t mention population if you can possibly avoid it.

The ‘demographic transition’

We are also told not to worry about the rising human population because the ‘demographic transition’ – the notion  that the population will stabilise naturally by the end of the century at about 11 billion – will eventually resolve the problem. This, however, totally ignores the severity of the environmental emergency we are facing, and the speed at which it is developing, and that even if it worked it would be far too late. We don’t even have until the middle of the century, let alone the end of the century to do something serious about it.

In fact armed conflicts over the impact of climate change are already under way. Of the 25 countries most vulnerable to climate impacts, 14 are already engaged in armed conflict. These include: Yemen, Mali, Afghanistan, Democratic Republic of the Congo and Somalia ­ which continues to face the longest drought in its history.

Meanwhile the Arctic sea ice will also soon be gone. Parts of Antarctica are warming 5 times faster than the rest of the planet. Both the Greenland and Antarctic ice sheets are destabilising – the melting of which would raise the sea level by up to 20 metres, and the world’s permafrost is now melting 50 per cent faster than was previously thought – with the potential to release vast quantities of methane, a powerful greenhouse gas (GHG).

The demand for fresh water has long outpaced replenishment. By 2025 (according to the UN), an estimated 1.8 billion people will live in areas facing serious water shortages, with another two-thirds – i.e. 7 billion – living in water-stressed regions. As rivers and aquifers dry up and droughts become ever more severe, conflicts over water become more intense.

The global South

We are even told that since most of the population increase takes place in the impoverished countries of the Global South – which also have the smallest carbon footprint – that it makes no significant contribution to global warming and climate change. Whilst their carbon emissions are much smaller than the Global West, they cannot, however, be dismissed as irrelevant.

These countries, like all of us, also have an ecological footprint, which measures their total impact on the planet including, for example: waste disposal, land, river, and oceanic pollution, soil depletion and erosion, deforestation, and biodiversity impact through both pollution and habitat destruction which paints a more negative picture of their ecological impact

People who are born in the Global South, moreover – either by choice or necessity – won’t and don’t necessarily stay there. People trapped in poverty, whether they are new arrivals or not, rightly aspire to the standard of living that others are enjoying in richer parts of the world, and we fully support them in doing so. Others will join the ranks of climate refugees having been forced from their homes by the impact of climate and extreme weather events. Last year the number of such these reached 100 million.

Carbon footprints are changing anyway. Some countries with the lowest carbon footprint today already have the highest economic growth rates, and therefore a big potential for such change. China’s per capita carbon footprint is already approaching 7 metric tonnes, after just two decades of capitalist growth. There is little point in assessing the impact of population increase on the planet over the next 50 or 100 years on the basis of a snapshot of today’s carbon measurements.

The radical left

It’s not just the political and religious elites, however, who are in denial about the consequences of rising human population numbers. It is shared – remarkably – by the radical and Marxist left who have held this position (to one degree or another) for 150 years since the critique Marx launched against the classical economist Thomas Malthus’s book  An Essay on the Principle of Population published in 1798. Malthus himself, of course, was of the previous generation and no longer around by the time Marx launched his critique.

Malthus, famously argued that since, in his view, population growth would always outstrip food supply, and since he was opposed to contraception on religious grounds, this meant that curbing population growth would have to be achieved by the abolition of the English Poor Laws. Such ‘charity’ he said would only encouraged more births which would mean yet more famine and starvation. His theory, however, collapsed in the middle of the 19th century as a result of the introduction of agricultural fertilisers, which massively raised agricultural productivity.

In fact, they were both predicting the collapse of capitalism through its own contradictions. For Malthus this would come via the collapse of the food supply and the onset of famine, for Marx it would come via economic crisis, social immiseration, rising inequality, falling wages, and declining profits. Neither were arguing that it would come via human induced ecological destruction.

Marx’s polemic, moreover, generated more heat than light. He lambasted Malthus as “a professional sycophant of the landed aristocracy”, and as a “slavish plagiarist” who “stole his population theory from his predecessors”, and an “utterly base” apologist who “will be agreeable (useful) to the aristocracy against the bourgeoisie and to both against the proletariat”.

A very good analysis of Marx’s polemic against Malthus can be found in chapter 11 of John Bellamy Foster’s 2002 book Ecology Against Capitalism. He points out that, in fact, Malthus never talked about overpopulation and he never talked about ecology:

“Contrary to most interpretations, Malthus’ theory was not about the threat of ‘overpopulation’ which may come about at a future date. Instead, it was his contention that there is a constant pressure of population against food supply which has always applied and will always apply… Far from being an ecological contribution Malthus’ argument was profoundly non-ecological (even anti-ecological) in nature, taking its fundamental import from an attempt to prove that future improvements in the condition of society, and more fundamentally in the condition of the poor, were impossible.”

Engels, in fact,  thought that population might have to be controlled under a communist society. In a letter to Karl Kautsky in 1881, he argued that whilst he was not currently alarmed about population growth (the population stood at 1.4 billion at the time) population numbers might have to be controlled in a future communist society:

“There is of course the abstract possibility that the human population will become so numerous that its further increase will have to be checked. If it should become necessary for communist society to regulate the production of men, just as it will have already regulated the production of things, then it, and it alone, will be able to do this without difficulties. It seems to me that it should not be too difficult for such a society to achieve in a planned way what has already come about naturally, without planning, in France and Lower Austria. In any case it will be for those people to decide if, when, and what they want to do about it, and what means to employ. I don’t feel qualified to offer them any advice or counsel in this matter. They will presumably be at least as clever as we are.”

The idea that Marx’s ill-tempered and confusing tirade against Malthusianism in the middle of the 19th century should determine our position on rising population in 2023, with the global population exceeding the 8 billion, is bizarre in the extreme.

It is a stance that prevented any objective discussion on the radical left on population throughout the second half of the 20th and led to the issue of population being increasingly seen as a taboo subject. It discredited any discussion on population in advance and has tarnished the role that the radical left have been able to play subsequently in the environmental struggle. Today anyone raising the subject on the left has to risk being denounced as a populationist, a Malthusianist, or a lot worse.

This was challenged ­as long ago as 1983 by the Canadian Marxist Wally Seccombe, in a remarkably prophetic article in New Left Review entitled ‘Marxism and Demography’. He argued that constant references to Malthus had “placed the debate on population beyond the pale of legitimate scrutiny and investigation”, and that in doing so, Marxists had abandoned the terrain to our enemies.

He puts it this way: “Marxism’s traditional primary address to demography, dating back to Marx himself, has been through a virulent denunciation of its Malthusian versions. These polemics, however programmatically justified in countering largely reactionary Malthusian population policies, nevertheless have had an anaesthetic effect upon historical materialism – placing the demographic realm itself beyond the scope of legitimate scrutiny and investigation.”

Wally Seccombe was absolutely right about it. Unfortunately, nothing changed and the taboo continues. I have come up against it multiple times over the past 17 years since I decided not to bow to it. I will reference three fairly recent examples:

In 2018, when I proposed to a major international conference of the radicle left, that population should be a legitimate subject for discussion by the Marxist left, I was met with a tirade of denunciation and it was voted down by 111 votes to 3. (Whether the notion of a taboo subject is compatible with a Marxist approach to debate and discussion is for others to say.)

During the COVID19 pandemic I was compared to Pol Pot for suggesting that population density was a factor in the spread of the virus. When I complained about this to the moderator of the website involved he agreed that it was ‘a bit harsh’.

I was called ‘borderline reactionary’ at a radical left meeting which was discussing the Dasgupta Review – The Economics of Biodiversity: The Dasgupta Review that had been commissioned by the UK government as preparation for COP15 and written by Partha Dasgupta, a professor of economics at St John’s College Cambridge. As soon as I said that agreed with one of the conclusions of the Review – that rising human population numbers were a major cause of biodiversity loss – the introducer of the discussion not only denounced me a ‘borderline reactionary’, but walked out of the meeting saying that he was not prepared to be part of anything that discussed population. (My review of the Dasgupta Review written before the meeting can be found here.)

The wider movement

Most of the wider environmental movement, however, recognises that rising population numbers are a problem to one degree or another. Both Friends of the Earth and Greenpeace avoid taking a position, probably to avoid the controversy it might generate. The Green Party, however, has an excellent, and very detailed position on it, in terms of both the consequences and the solutions – though you have to go to their website to find it.

Its opening paragraph says that: “There is a limit to the level of ecological impact the Earth can sustain. The number of people on the planet, their levels of consumption and their local and global impacts are key factors determining how far the Earth’s ability to renew its resources and to support all life is compromised. Even within this limit, high rates of population growth, as well as local depopulation can have a damaging effect on sustainability, equity and justice.”

The climate campaigning organisation Avaaz says the following in a brief statement on the 8 billion landmark: “Humanity has become a weapon of mass extinction. As the human population tops 8 billion, the rest of life is being decimated. We’ve destroyed two-thirds of the rainforests, half the coral reefs, and a million species are now facing oblivion. Right now, governments and scientists are in final negotiations for a new global deal to stop the destruction of nature, but there’s real danger it will be weak and full of holes.’

The Limits to Growth debate

The socialist left in Britain supported economic growth for most of the 20th century, in both the Labour Party and the trade unions. In the 1980s, for example, the strategic bible of the Bennite left (inside and outside of the Labour Party) in the early 1970s was a 150-page document entitled The Alternative Economic Strategy. One of its key chapters entitled ‘A Policy for Expansion’ starts with the following: “The essential basis for any alternative economic strategy must be a policy for planned economic expansion”. The ecology of the planet is not mentioned anywhere in its pages.

The most important book, from a left environmental perspective, on the limits to exponential growth on a finite planet was The Limits to Growth a Project on the Predicament of Mankind published in 1972. It was written by  team of young scientists led by the environmental scientist Donella Meadows from the Massachusetts Institute of Technology (MIT) and  commissioned by the environmental campaign the Club of Rome.

It sold 12 million copies, was translated into 37 languages, and it remains the top-selling environmental title ever published. It was also instrumental – along with Rachel Carson’s Silent Spring 10 years earlier – in the emergence of the modern environmental movement.

The conclusion it reached was that it is impossible to have exponential growth of either the population or of the economy – which they saw as synonymous – on a finite planet such as Earth without its ecosystems sooner or later collapsing.

They put it this way: “If the present growth trends in world population, industrialisation, food production, and resource depletion continue unchanged, the limit to growth on this planet will be reached sometime in the next hundred years. The most probable result will be a sudden and uncontrollable decline in both population and industrial capacity.”

Their bold – and as we can now see highly accurate – conclusion, however, was attacked by establishment scientists as a doomsday scenario and completely ignored by the socialist left.

A similar conclusion was reached by a review of the book that was undertaken by the University of Melbourne on the 40th anniversary of Limits to Growth in 2014.

This was reported by the Guardian of September 2nd 2014 with a headline saying that the  “Limits to Growth report was right. New research, it says, shows that we’re nearing collapse.” It went on: “Four decades after the book was published, Limits to Growth’s forecasts have been vindicated by new Australian research. Expect the early stages of global collapse to start appearing soon”

The role of the UN

The UN – which was and is the obvious body to address such a global phenomenon as population – in fact has a good of record on the issue, going back to the early post-war period. It’s Population Division was established in 1947 went on to organise four international conferences on population between 1954 and 1984. These were Rome in 1954, Belgrade in 1965, Bucharest in 1974, and Mexico City in 1984. They were all opposed by pro-life forces led by the Vatican and several were disrupted.

The Earth Summit in Rio de Janeiro in June 1992  the – UN Conference on Environment and Development –  which adopted the UN Framework Convention on Climate Change – also addressed the issue of population growth by recognising that: “Pressures resulting from unrestrained population growth puts demands on the natural world that overwhelm any efforts to achieve a sustainable future. If we are to halt the destruction of our environment we must accept limits to that growth.”

The UN’s most important initiative to date on population increase was the International Conference on Population and Development in Cairo in 1994 which went on to agree a detailed Programme of Action to address population growth based on the empowerment of women to control their own lives and their own bodies. It also launched a campaign with the objective of making family planning and reproductive services available to all women on the planet by 2015.

This meant giving them access to education and lifting them out of poverty. It also meant supporting them in their battle against religion and other conservative influences such as patriarchal or communal pressure, which denies their right to choose the number of children they will have. It was a win-win proposal since all these demands were the traditional demands of the women’s movement and necessary any way. As I say in Facing the Apocalypse (page 144):

“Women have historically demanded and fought for the right to control their own fertility, and continue to do so today – including in those parts of the world with the highest birth rates. Women are the active agency in this field, including in the struggle against enforced control. Reproductive rights were the lynchpin of the feminist movement of the 1970s and 1980s; and by struggling for their own specific interests, women often also become the agents of wider change.”

The Programme of Action, however, faced massive opposition from pro-life forces, again led by the Vatican. Many of the governments that had initially supported The Programme of Action pulled out, and its achievements were severely weakened. Although, the most recent population conference in Nairobi re-endorsed the Programme of Action and called for its full implementation this remains very difficult under today’s conditions.

Feminists were divided on it, however  – mainly along global North/South lines. The Indian environmental activist Vandana Shiva, for example, accused Western feminists who supported the Programme of Action, (falsely in my view) of having been duped by the UN. She argued that any programme designed to give women in the Global South access to reproductive services would inevitably end up introducing coercive population control.

The conference, in the end, was a major lost opportunity in terms of enhancing the ability of women to control their own bodies and their own lives– particularly for women in the impoverished parts of the Global South.

(A debate between Betsy Hartmann who opposed the Programme of Action and Laurie Mazur who supported it – it can be found in my book Facing the Apocalypse.)

Cairo revisited

In 2010 – 18 years later – the Cairo conference and its Programme of Action was revisited by the American feminist and environmentalist Laurie Mazur in her book A Pivotal Moment – Population, Justice, and the Environmental Challenge.

Her balance sheet, however, was that whilst the ecological crisis was now far worse, the matter of the rising human population remained entirely unresolved. The world’s nations she said “have not kept the promises made in Cairo. In the US, the very success of the Cairo conference invigorated conservative groups who oppose family planning and wider opportunities for women. With the advent of a conservative Congress in 1994 followed by the Bush victory in 2000 those groups amplified their political power”. The US, she said, had cut its aid for family planning programmes by almost 40 per cent.

As a result of this she said: “Countless women and men lack the power to make real choices about childbearing  because of crushing poverty or persistent gender discrimination. The neglect of the Cairo agenda means that over 200 million women in developing countries, who wish to delay or prevent pregnancy still lack access to family planning services and to maternal health services in remote areas.

What made the failure remarkable, she argued, was that: “Everything we must do to slow population growth – ensuring access to reproductive health services, improving the status of girls and women – is something we should be doing anyway.

The backlash against Mazur’s book came a year later with the publication of Too Many People? by Ian Angus and Simon Butler. They were not only in denial about the rising human population of the planet, but were completely opposed to the Programme of Action which they insisted promoted coercive population control. Throughout the book the charge of ‘Malthusianism’ or ‘populationism’ is aggressively levelled against anyone who suggests that rising population is a legitimate, let alone important, subject for discussion on the left. They argued the same with the call for the universal provision of reproductive services, despite it being based on a woman’s right to choose – and despite knowing full well that both Laurie Mazur and the UN were opposed to coercive control.

Angus and Butler put it (patronisingly) this way: “Most supporters of population control today say that it is meant as a kindness — a benevolent measure that can empower women, help climate change, and lift people out of poverty, hunger, and underdevelopment. But population control has a dark past that must be considered by anyone seeking solutions to the ecological crisis.”(page 83) They go on: “…At its most extreme, this logic has led to sterilisation of the ‘unfit’ or ethnic cleansing. But even family planning could be a form of population control when the proponents aim to plan other people’s families.” [page 84] My contemporary review of Too Many People? can be found here.

What the Programme of Action actually targeted, of course, was the appalling conditions that the women of the Global South face in terms of the lack of reproductive services they are forced to suffer. According to the UN, modern reproductive services are still unavailable to at least 350 million couples world-wide, who want to prevent another pregnancy or to create more space before the next one. There are 80 million unintended pregnancies a year – which is equal to the annual global population increase. Around 74,000 women die every year as a result of failed back-street abortions, with a disproportionate number of these from the Global South.

In any case the idea that most women in the Global South, given a genuine choice, would choose to have the large families that many have today is hard to accept. Some would, most probably would not. Multiple pregnancies, with little space between them, wreak havoc in terms of the health and life expectancy of the mothers concerned. Most women are under pressure from either the state, from religion, patriarchal and cultural pressures to have more children, or they are denied the means by which to avoid having more children.


The radical and Marxist left needs a complete rethink on population in order to play a significant role in the transition to an ecosocialist society. We have to get beyond the nineteenth century name-calling and root our debates in the existential challenges of the  21st century.

Any assessment of the ecological crisis today that fails to consider the  average of 70 to 83 million extra people that are added to the planet every year is deeply flawed. The issue of population, we have to insist, is an important and wholly legitimate issue for the left to discuss. Taboos have no place in such a discussion.

We cannot continue to wash our hands of the impact our own species is having on the planet on which we live. In fact we have a responsibility not to do so. Our vision must be for a future in which the human population is able to live in harmony with the rest of nature and all other species on the planet and  to the benefit of all. Nothing else works.

As Engels insisted in his Dialectics of Nature in 1833: : “Thus at every step we are reminded that we by no means rule over nature like a conqueror over a foreign people, like someone standing outside nature – but that we, with flesh, blood and brain, belong to nature, and exist in its midst, and that all our mastery of it consists in the fact that we have the advantage over all other creatures of being able to learn its laws and apply them correctly.”

This means looking towards a society in which humankind can exist alongside other species without threatening their very existence. Such an approach is not anti-people as it is being framed in this debate but entirely pro-people. Its objectives are not reactionary but wholly progressive. Stabilising the human population at a sustainable level is good for the planet, it is good for  biodiversity and it is good for the human population.

We have to build a global mass movement that can save the planet, but there is a big political problem – it will need a big progressive content if it is to go in the right direction. Without such a content, which the radical left must aim to be a part of, it would be as likely to go to the right as to the left. Only a mass movement with a strong progressive content can defend the planet in such a situation. And if we are to be a part of building such a movement we have to establish our credentials in the here and now. In the struggles that are taking place today, and those that are just around the corner.

It is hard to see how any capitalist economy could survive without economic growth since it is its reason for existence. Or, as Giorgos Kallis, the best writer around in my view on degrowth has put it: “Growth is what capitalism needs, knows, and does.” To have any chance of surviving without economic growth the stabilisation of human population numbers would be a necessary condition. If it is our aim to build a post capitalist ecosocialist society that rejects growth, the same would apply;­ the human population would have to be either stabilised or reduced.

Alan Thornett, January 22nd 2023


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