The environmental toll of having even one child is enormous - 58.6 tonnes of carbon each year. So is going child-free the answer to our climate crisis?

Gwynn Mackellen was 26 when she decided to get sterilised. It took the recycling consultant, who is based in California five years to find an appropriate doctor under the public health plan she was on, but she was determined. In 2012, she succeeded. “I always knew I didn’t want kids, for environmental reasons,” she says.

“I work in the waste industry, and our waste is the downstream of people. It’s not people being bad; it’s just the effects of people.” Just as it’s not only bad people deforesting, she says: “The trees are being cut down on our behalf. Plastic waste is being dumped and minerals are being mined not because of bad people, but because of people. Having fewer of us, there will be less of those effects.”

Mackellen identifies as an antinatalist, a philosophical movement based around the tenet that it’s cruel to bring sentient lives, doomed to suffering and to causing suffering, into the world. “Or at least I think our culture is very pro-natalist and it’s to our detriment. I would like to see us voluntarily reduce our population.” But cultural pressures, she says, drive people to have children by celebrating childbearing without acknowledging the consequences for themselves and the planet.

Gwynn Mackellen, who was sterilised at the age of 26. Photograph: Ingrid Beesley

“My mum grew up thinking that getting married and having kids was what you did, but she raised my sister and me to not feel like those were our only options.” Her stance has posed no problems to her partner of 10 years, and many of those around her were congratulatory when she was sterilised. “I live in the liberal [San Francisco] Bay area,” she says, “and I’ve always been really vocal about this.” However, she can’t always discuss her concerns about human population with friends, which is why she is part of a community called the Voluntary Human Extinction Movement, or VHEMT (pronounced vehement) for short. Despite the drastic-sounding title, the organisation welcomes those whose end goal isn’t necessarily human extinction, along with parents who have come around to the VHEMT perspective to some degree. The organisation’s literature is rational and often humorous in tone and, says Mackellen: “It’s nice to talk openly with people who have similar feelings and frustrations, like when I read the environmental news and think: wow, how could anybody produce a new human when the effects of humans are very obvious, I feel, and the situation is getting worse.”

The UK-based organisation Population Matters wouldn’t call for human extinction – even in jest – but it does campaign against population growth which, it says, contributes to environmental degradation, resource depletion, poverty and inequality. To its list of influential patrons, which already includes David Attenborough, Chris Packham, Lionel Shriver and the primatologist Jane Goodall, it has recently added the racing driver and environmental activist Leilani Münter. She’s an eloquent positive-thinker. “Never underestimate a vegan hippy chick with a race car,” is how she describes herself online.

Facebook Twitter Pinterest Racing driver and environmental activist Leilani Münter: ‘My husband and I are child-free by choice.’ Photograph: Scott R LePage

When people ask her if she has children, Münter, who is 44, has a prepared answer: “No, my husband and I are child-free by choice.” Saying child-free, she argues, doesn’t imply you are deprived, as the more standard “childless” might. And by letting them know it isn’t a sad topic to be avoided, she says, “it opens up the door for them to ask: ‘Oh, that’s interesting, why did you choose not to?’” Münter wants to move the awkward topic of overpopulation into the mainstream. “The more we talk about it, the more comfortable people will feel talking about it and then, maybe, things will change.”

For too long, she feels, the issue has been swept under the rug. “We can talk about emissions and climate change, but talking about population gets such an emotional reaction.” However, Robin Maynard, the director of Population Matters, says he has noticed an upsurge in support, particularly among young people. “You can measure it in our online traffic – our Twitter followers are up by 60% from 2016 and a recent Facebook post on being child-free reached more than 4 million people. We are getting more and a wider range of people wanting to join us – and an increase in approaches from donors.” This, he says, “is underpinned by the growing body of scientists stating that humanity must address the issue of our numbers, as well as our consumption”.

Münter hadn’t considered the implications of population size until she was in her early 20s. “I was studying biology at the University of California and came into a lecture that I assumed would be about biochemistry, but the professor showed us a documentary on population.” She says she was “blown away” by the numbers. “It took humans 200,000 years to get to our first billion people, then 126 years to double to 2 billion, 30 years to add another billion and 14 years for the next billion.” Each subsequent billion has only taken 12 years. “It’s pretty scary,” says Münter.

We can embrace all the electric cars, renewable energy sources and plant-based foods we like, but, she believes, this can’t make up for overpopulation. Münter subscribes to one of the most conservative estimates of the Earth’s “carrying capacity” (how many humans the planet can sustainably support) by researchers at Cornell University in 1999. “Assuming that all humans are living in relative prosperity, with access to clean water and electricity, that number is 2bn, so we are already 5.6bn over that and rapidly adding people every day.”

'Your kids and your kid’s kids will be the ones who benefit from humans deciding to slow down our rate of growth'

The last thing she wants to do is make parents feel guilty, or to shut them out of the conversation. Procreation, after all, is natural. And if you have two children, you are only replacing their parents, rather than adding extras. But if you’re not yet a parent and can’t suppress your parental instincts, says Münter, “my ask is that you consider adopting one of the 153m orphan children that are already on the planet and need a home. Or, if you are dead set on having your own, my hope would be that you just have one and then if you want more, adopt.” Ultimately, she says, “your kids and your kid’s kids will be the ones who benefit from humans deciding to slow down our rate of growth. It will slow down climate change, ocean acidification, cutting down the wild places.”

Writing in response to Münter’s new role with Population Matters, Jeremy Clarkson rolled out the parental platitude that his children “are the point of my existence”. This may be true in evolutionary terms – our prime biological function is to perpetuate our genes/continue the line – but whether it’s also emotionally/rationally/intellectually true for all parents is moot, and many would say it is a fallacy that life without offspring is necessarily less meaningful. Münter, an active aunt, argues that she has greater purpose and can make a bigger impact than she would if she were a mother. “I don’t feel like I’m missing out,” she says. “Through my activism, I get to talk at schools and universities, reaching thousands of kids. If I had my own children, I wouldn’t have time. I’m satisfied and fulfilled and don’t need to have a mini-me to pass on these ideas.”

This view is shared by Emma Olif, a board member of Population Matters who lives off-grid in a caravan, travelling between rural England and Spain. “People have got very narrow-minded about what it means to be meaningful as a person,” she says. “We have so much opportunity these days to do important things and be pregnant with more than children. We can be pregnant with ideas and dreams and revolution.”

Emma Oliff: ‘I’ve got four siblings; my genes are fine.’ Photograph: Rebecca Hosking

Having children, she says, “from a biological point of view, is probably one of the most selfish things you can do. You’re stealing resources from others in order to perpetuate your genes. I’ve got four siblings; my genes are fine. And the things I want to pass on are intellectual. I will have far more time to do that to a greater number of people if I don’t have children.”

With a marine biology degree and a masters in biological diversity, Olif, 30, says she has never had a maternal drive, “because I’ve always been aware of everything that’s going on around me, economically, politically and environmentally,” she says. “The climate isn’t suitable for having kids at the moment.”

The argument that many richer countries have falling birthrates doesn’t wash. “The impact of humanity on the environment in the west is significantly more, because we consume more.” She mentions a recent Swedish study that found that having one les child per family can save an average of 58.6 tonnes of carbon every year. The next biggest carbon saving you could make is by going car-free, saving a minuscule-by-comparison 2.4 tonnes.

'When I sum up all the reasons to have, or not to have, a child, it just doesn’t make sense for me'

Olif frequently gets told that she’s too young to decide not to breed, and that she’ll change her mind. But she is at the age her mother was when she had her. “And all my friends are having children. If they’re old enough to make the decision to have children, surely I’m old enough to make the decision not to.”

One of the biggest hurdles for women, she acknowledges, is that they can decide they don’t want children, “but physically, their body is raging. We are biologically programmed to have kids.” Which is partly why, she says, “it’s seen as a bit weird not to have kids”.

Alex Smith, a software developer in Suffolk, decided as a child not to create any new humans. His wife didn’t want children, either, but throughout their 15 years together, he says, “we’ve revisited it on a regular basis, checking we both still feel the same, and we’ve never changed our minds.” At 41, he’s in a child-free minority, as most of his friends have started families. “My impression is that having a family is just instinctive and natural and most people don’t think about the impact.” He would never tell anyone not to do it, but if the subject comes up in conversation, he’ll politely suggest considering having only one child. “We need to reverse this population [growth] and that’s certainly one way to do it.”

Facebook Twitter Pinterest Angela and Xavi Cortal: ‘We decided to go with a rescue dog instead of a kid.’ Photograph: Courtesy of Angela and Xavi Cortel

When Angela and Xavi Cortal, who live in the US near Portland, Oregon, met 12 years ago, Xavi didn’t want children, but Angela, a naturopathic doctor, was still undecided. “The narrative was the assumption: of course you’ll have kids, why wouldn’t you continue the family?” But after thinking long and hard, she decided instead “to be connected with family and society in other ways that are fulfilling … I think of myself as a very left-brain, analytical, logical person and when I sum up all the reasons to have, or not to have, a child, it just doesn’t make sense for me.” The pair talked about fostering and adoption, “but we decided to go with a rescue dog instead of a kid,” she says.

At a summer fair in Portland seven years ago, she met the founder of VHEMT, Les Knight. She liked how he had condensed all the data about the environmental impact for each person, “acres of forest potentially preserved by each person not brought into the world … It’s very logical in a very tongue-in-cheek way and I don’t think there’s anything I disagree with.” A lot of the reasoning, she says, “might feel confrontational or unwelcome by people of other perspectives”, although the call for actual extinction, she feels is tongue-in-cheek. “I don’t necessarily hope all humans will die out – I hope we can change the use of resources and impact on the environment.”

Xavi works for an accredited organic certifying agency and first decided to stay child-free in his 20s, influenced by a woman he was in a relationship with who didn’t want children. Once he considered the benefits – personal and wider – “everywhere I looked I found a new affirmation for my decision.”

The social pressures for men, he says, are different but still present. “Men seem to have this machismo-based belief that their superior genes need to be carried forward … [but] I think that women have more societal pressure on them to reproduce.” He sees a “disappointing reluctance by men who say they don’t want kids to surgically make sure it doesn’t happen when a vasectomy is so much quicker and less invasive than making a woman undergo tubal ligation. Testes are not sacrosanct.” Xavi had a vasectomy at 26 and calls it “the best $500 I ever spent”.

He readily admits that his motivations aren’t entirely selfless. “Child rearing is a miserable, thankless, expensive grind that I don’t see as necessary and that I don’t want to participate in. Of course, my mother loves me and I love her, but why would I want to repeat what I put my parents through? Guilt? Obligation? Duty? No thanks. I get to travel, save money, sleep in if I want to. I get to hang out with other people’s kids and then give them back when they’re rude. There’s really no downside.”

While he believes the planet would fare better without humans, he says he cannot fathom human extinction. “This is the world I know. I do a lot of civic work and that has become my children. If I can better the world around me, that’s better than some snotty brat that’s going to tell me that I did a lousy job raising them.” Despite being a supporter of VHEMT, Angela wouldn’t call herself an antinatalist, because she associates it with negative feelings towards humankind. “I don’t, on a human level, resent people who have kids. That wouldn’t be constructive at all. Both my sisters have children.”

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The term is also strongly associated with the writings of the philosopher David Benetar, the author of Better Never to Have Been: The Harm of Coming into Existence. Mackellen, who does call herself an antinatalist, says her thinking leans his way. “He has thought about it a lot and has come to an acceptance that if creatures are born, they’re going to suffer, therefore let’s not make new ones. I tend to agree.” But she has mixed feelings. “I also work with people in the community and I really enjoy it. I have somewhat of a background in science and I love so many of the things we’ve accomplished. So I’m not completely anti-human, but I understand where he’s coming from.”

It’s easy to wonder whether Benetar and many antinatalists are simply depressed. Mackellen disagrees: “It’s been challenging at times, but for the most part I’ve had a good life,” she says. “I’ve never been suicidal. I’d actually like to live a long time and be healthy for the rest of my life.” Her concerns for humans are mostly environmental, “what new people will experience with global warming and microplastics in our water. I think it would be unfair of me to create new people to have a worse life than mine.”

She feels that the best way to reduce human suffering is to invest in the people we already have, with access to healthcare, living-wage jobs and better education, “especially for girls and women. And free and equitable access to contraception and more social pressure to not have kids or have fewer children.”

Angela Cortal sees deciding whether to have children as “probably the most important decision that someone is going to make in their life, and their family, society or even religion should not be making a decision of that magnitude for them. It’s OK to think about it and come to your own decision.”