“We’re taking things from the people of the future now,” Mary Heath says from the kitchen where she’s drying seeds to plant. The climate activist is talking about Earth Overshoot Day, the ominous annual milestone that marks when humanity has consumed more from the Earth than the Earth can replenish in a year.

Globally, the deficit started on 1 August, meaning we are “using nature 1.7 times faster than our planet’s ecosystems can regenerate”.

Australia’s own overshoot day was 5 April.

In the face of the climate crisis, resource exhaustion and biodiversity calamities, corporations and governments remain wedded to the notion of eternal growth.

But there’s a growing movement trying to slow or stop the rate of increase. Or even to shrink the economy to save the world. And they’re not talking about reducing the quality of life anywhere, let alone in developing economies. They’re talking about sustainability, valuing resources other than money and recognising that infinite growth is impossible, and the pursuit of it catastrophic to the planet.

Heath is an energetic and passionate example of those who want to put the brakes on. Call it anti-consumerism, anti-capitalism, degrowth, post-growth – or a return to simpler times.

She’s darning dozens of holes in an op-shop jumper, running six different compost heaps, making worm farm covers and cushions out of old denim jeans using her grandmother’s overlocker. She made a shroud for a dear friend from the clothes the friend had loved.

A guerrilla gardener, she gathers and propagates seeds, planting natives in neglected corners of her Adelaide suburb.

Back in 1992 Bill Clinton’s press secretary James Carville coined the phrase “It’s the economy, stupid”. It still echoes around election campaigns with the striking appeal of simplicity.

But there has been an uptick in people questioning whether we are being, well, stupid about the economy in our pursuit of “growthism”.

The latest push for growth has focused on the fertility “crisis”, the ageing population and their flow-on effects to the economy.

With fertility rates plunging, the pool of young taxpayers will shrink and become incapable of supporting the swelling ranks of the old, the argument goes. And a growing population means a growing economy, which means … what, exactly?

While economic growth has lifted millions out of poverty, it has hardly delivered equality. Statistics show the largesse overwhelmingly ends up in the pockets of the already-rich. And endless economic growth is inextricably tied to consumption, which in turn is disrupting the parallel push for sustainability.

Think about the super-rich and their super-yachts.

Not to mention the problematic premise, which is that women bear the responsibility to bear the humans that will help feed this endless growth.

The world’s population is, at this point, still growing. Nandita Bajaj, the executive director of the US non-profit Population Balance, says there’s a taboo around discussing population among those who oppose eternal growth. She told a forum this week that population and consumption (and therefore emissions) go hand in hand but there are reasons the left and the degrowth movement duck the conversation.

Even though the Intergovernmental Panel on Climate Change says “globally, gross domestic product (GDP) per capita and population growth remained the strongest drivers of CO2 emissions from fossil fuel combustion in the last decade”, Bajaj says people are still “so nervous” to talk about the connection. It’s a taboo.

That’s because there’s a combination of human exceptionalism, entitlement and superiority, she says, along with a repugnance towards past policies to reduce birth rates that have been coercive, and pronatalism, which is a push towards having more children for greater political power, or pressure to grow the economy or to “have more taxpayers”.

A University of Queensland economist, Prof, John Quiggin, says the whole fertility crisis is “bogus” – and not just because policies to address it appear to be universally failing.

“Economically, the cost of raising children is much higher than the cost of looking after old people,” he says.

But that cost is born by parents, so in a sense they’re giving “a free gift to society”.

“The odds are you’ll be in reasonable shape until about six months before you die at which point you’ll need about the same care as a baby,” he says. “So raising a baby to look after an old person makes no sense.”

Sandra Kanck, a former Democrats senator and national secretary of Sustainable Population Australia, agrees. “The cost of raising a child is way more than the cost of putting someone in aged care,” she says, adding that having more children puts more pressure on the planet.

“So the resources we think are available to us are not available to our children,” she says. “It’s contributing to climate change and creating greater instability.”

As for fears about an ageing population, she says, these are based on flawed assumptions. “Like that everyone over 70 is basically senile, and that all the baby boomers will end up in aged care,” she says.

“Most of them are making an incredible contribution. Many are still in the workforce … and those who have retired are operating a free babysitting service for their grandchildren.”

The growth myth

More broadly, the UN special rapporteur on extreme poverty and human rights, Olivier De Schutter, has talked about “the ideology of ‘growthism’” and says it “should not become a distraction from the urgent need both to provide more of the goods and services that enhance wellbeing and to reduce the production of what is unnecessary or even toxic”.

De Schutter writes that governments “still act as if infinite growth were possible” and argues that growth in GDP is not necessary.

“Moving from an economy driven by the search for maximizing profits to a human rights economy is possible and, to remain within planetary boundaries, necessary,” he wrote in a July report.

Ian Lowe, emeritus professor in the School of Environment and Science at Griffith University, says increasing the population is just the easiest way to keep growing the economy. “But if the economy grows by 3% and the population grows by 3% no one’s better off on average,” he says.

“If the population keeps increasing, then just to stay where you are in terms of the environmental impact you have to reduce the environmental impact per person.

“Sooner or later, if we don’t stabilise the population in ways that are socially acceptable it will be stabilised by disease and fighting amongst ourselves.”

Kanck says: “Nature bats last. It’ll be the planet that hits back and decides what the population levels are.”

There are other ways to tackle poverty, social exclusion and inequality, De Schutter says. The productive economy depends on the “so-called reproductive economy”, he writes, “which takes place within households and communities, without remuneration, and to which women are the main contributors”.

We should recognise care work – caring for children, parents, dependents – and value it, he says, while pointing out that post-growth scenarios do not mean austerity but a transition to society reducing addiction to growth. About human rights, not an endless quest for more.

An emeritus professor at the Australian National University’s college of arts and social sciences, Peter McDonald, says there are three drivers of economic growth – “population, participation and productivity” – and population is not the best option.

“Nothing beats productivity,” he says. “If you’re able to have high levels of productivity the other two are supplementary. But in recent times Australian productivity has been pretty bad.”

Lifting productivity, and therefore living standards, is often done through new technology he says, and artificial intelligence could be part of the answer.

‘I’m scared stiff’

Still, the idea of shrinking appears to be, well, growing.

Some people are embracing degrowth, ditching fast fashion, and consuming less to reduce their impact on the planet – especially during the cost-of-living crisis.

A 2023 YouGov survey found almost half the Britons surveyed said environmental sustainability was affecting their purchase choices.

“Underconsumption core” has become a trend on social media. People are showing off their thrifted goods, their well-worn clothes, their ability to reduce, reuse and recycle, as an antidote to mass consumerism and fast fashion.

For Heath, it’s a question of ethics or integrity (plus education and enjoyment). She’s not telling anyone else what to do, or deluding herself that one person’s actions could fix it all. But we have to stop the eternal growth, she says. And that means organising, and collective action to force change.

“We need to normalise that we’re living through a climate emergency … we’re living through the breakdown of the natural world, and we can’t afford this level of waste.”

Heath has a stepdaughter and says she doesn’t feel the way some do, that a DNA connection makes someone more important than anyone else on the planet. “I just feel like, ‘Why do I need to reproduce? There’s not a shortage of people, young people, who need extra adult attention in their lives,’” she says.

In 1968 Paul R Ehrlich published The Population Bomb, which sparked fears of mass starvation due to overpopulation and the inability of the planet to provide for the masses. He revisited the notion in his memoir, Life.

The book is still a “useful lens” he writes, “despite its flaws”.

“It introduced millions of people to the fundamental issue of the Earth’s finite capacity to sustain human civilization.”

He writes that he was targeted at the time because of the economic “fairytale” that population growth and expanding per-capita consumption would see “human enterprise forever expanding, along with human happiness”, while ignoring the true costs of production, including the environmental costs.

He welcomes the drops in fertility rates, saying there is a desperate need for population shrinkage.

“But I’m scared stiff that we don’t have more than a couple of decades to change our ways as the biophysical and social existential threats, virtually all exacerbated by population growth, are increasing rapidly,” he wrote.

“We are, after all, already in overshoot.”