Should We Have Smaller Families To Save The Planet?

Summary

Podcast Summary: More or Less – Should We Have Smaller Families To Save The Planet?

Host: Wesley Stevens (BBC Radio 4)
Date: July 15, 2018

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Episode Overview

This episode delves into the provocative question: Is having children the worst thing you can do for the environment? The discussion centers on the impact of family size on individual and global carbon footprints, scrutinizing science, statistics, and ethics. Experts and researchers weigh in on whether reducing family size is truly the most significant action an individual can take to combat climate change—or if systemic and technological changes offer a better path forward.

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Key Discussion Points and Insights

1. The "Carbon Legacy" of Having Children

• Lucy Proctor admits personal anxiety after learning the carbon impact of having children may dwarf her other eco-friendly behaviors. (00:35)
• Research by Seth Wynes:
  • Living car-free saves approximately 2.4 tonnes of CO₂ per year.
  • Not having a child saves a staggering 58 tonnes of CO₂ equivalent per year (developed world average). (01:26)
  • Reason: Each child potentially leads to many generations of descendants all emitting CO₂ (“your carbon legacy”).
  • For the US, one child’s long-term legacy is estimated at 9,441 tonnes of CO₂. (02:52)
• Wesley Stevens reacts:

  “So each child actually leads to 9,500 tons of carbon. That's not a big. That's a huge figure.” (02:52)

2. The Broader Debate: Individual Actions vs. Systemic Technological Solutions

• Academics are divided between those favoring personal responsibility (individual action, such as having fewer children) and advocates for technological intervention and policy. (03:49)
• Bjorn Lomborg (Copenhagen Consensus):
  • Questions the methodology that makes individuals responsible for all future emissions of their descendants.
  • Argues technological innovation will likely reduce emissions per capita, so projecting today’s carbon outputs far into the future is unrealistic.
  • Criticizes the assumption parents are morally responsible for their grandchildren’s decisions. (04:10)

  "It seems very unlikely that children far into the next century will still be emitting say, 15 tons per year, as a rich American is doing right now. Much more likely we will have develop[ed] technology that will allow us to reduce our emissions dramatically, maybe even very close to zero." — Bjorn Lomborg (04:47)

3. Does Smaller Population = Big Impact?

• Historical perspective: The “population bomb” theory by Paul Ehrlich in the 1970s predicted disaster due to overpopulation, which technological improvements in food production ultimately averted.
• Corey Bradshaw (ecologist, received death threats for his work):
  • Modeled the impact if global fertility dropped from 2.4 to 2 children per woman.
  • Results: Population in 2100 would be halved—from a projected 13 billion to about 7 billion—but total emissions would only drop by 7%. (06:55)
  • Most emissions cuts would come from countries with currently high birthrates but low per-capita emissions (mainly Africa).

  “…only translates into a 7% decline in total emissions from now to the end of the century...that's nothing to sneeze at by itself. It won’t be enough.” — Corey Bradshaw (07:19)

• Momentum factor: Even a global one-child policy wouldn’t sharply reduce population by 2100 due to demographic inertia. (07:46)

4. Experts' Personal Choices and Final Recommendations

• Personal decisions:
  • Seth Wynes does not have children; Corey Bradshaw became a parent by accident but is unconvinced that population control alone solves climate change. (08:17)
  • Wynes advocates for high-impact personal actions: smaller families, avoiding air travel, car-free living, and a plant-based diet. (08:44)

    “If you're interested in making those most important changes, they are having a smaller family, avoiding air travel, living car free, eating a plant-based diet.” — Seth Wynes (08:44)

• Where do the experts agree?
  • Population control is not the answer; it must be paired with deep cuts in carbon intensity of consumption. (09:18)
  • System change vs. individual impact:
    • Seth Wynes and Corey Bradshaw emphasize the value and scale of individual choices.
    • Bjorn Lomborg stresses that without systemic technological change and political will, individual action offers limited relief.

    “Individual action on climate change rarely will lead to very much impact because it is a small impact...what really is necessary...is about getting technological change.” — Bjorn Lomborg (09:34)

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Memorable Quotes & Timestamps

• Wesley Stevens:

  “Is having children the worst thing you can possibly do for the environment?” (00:07)

• Lucy Proctor:

  “I did start to worry that all my environmental do gooding was basically meaningless compared to the toll my two kids are inevitably going to take on the planet's finite resources.” (00:35)

• Seth Wynes:

  “The kind of person that might type in, what are the 10 most important things I can do to prevent climate change? And who are actually looking for a top 10 list?” (01:13)

• Corey Bradshaw:

  “Moving towards 2 children per woman on average globally would end up...reducing the population trajectory by about 50%...that only translates into a 7% decline in total emissions from now to the end of the century...It won’t be enough.” (06:55–07:19)

• Bjorn Lomborg:

  “It seems very unlikely that children far into the next century will still be emitting say, 15 tons per year, as a rich American is doing right now. Much more likely we will have develop[ed] technology that will allow us to reduce our emissions dramatically, maybe even very close to zero.” (04:47)

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Important Segments & Timestamps

• Introduction and framing of the “carbon legacy” question: (00:05–01:22)
• Explanation of Seth Wynes’ carbon footprint research: (01:26–03:43)
• Debate on methodology and future assumptions (Wynes vs. Lomborg): (03:49–05:37)
• Population narrative past and present (Ehrlich, Bradshaw): (05:37–07:31)
• Impact of lower fertility in high vs. low emission countries: (07:31–08:17)
• Experts’ choices and recommendations (individual vs. systemic action): (08:17–09:34)

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Conclusion

The episode offers a nuanced exploration of whether smaller families are key to solving climate change. While having fewer children can dramatically lower an individual’s projected carbon legacy, demographic trends and per-capita consumption patterns mean that population control alone cannot deliver the major emission reductions needed. The biggest consensus: while individual choices matter, especially for those ready to “step it up a notch,” system-wide technological and policy innovations remain vital to success.

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For further analysis or listener questions, email [e-mail].

Transcript

[A]

Hello and welcome to More Or Less on the BBC World Service with me, Wesley Stevens. Now, this week we're looking at a controversial topic, so much so that one of the academics we're going to hear from has received numerous death threats. So no death threats please, listeners. But here's the question. Is having children the worst thing you can possibly do for the environment? Yes. It's not cheery talk about family, we're talking about cutting down on the family. Lucy Proctor's been looking into this. Hi, Lucy.

[B]

Hello. Yes, I'm one of those people that recycles and shouts at my partner for leaving the car idling. So when I came across this idea, I did start to worry that all my environmental do gooding was basically meaningless compared to the toll my two kids are inevitably going to take on the planet's finite resources.

[A]

That's quite a harsh way to look at your kids.

[B]

I know. I'm blaming Seth Wins. He's a PhD stud at the University of British Columbia. He got me thinking like this. He set out to compare all the things we're told we should do to reduce our carbon footprint, from recycling to mowing your lawn less. He had someone like me in mind,

[C]

the kind of person that might type in, what are the 10 most important things I can do to prevent climate change? And who are actually looking for a top 10 list?

[A]

And the top action an individual can take to reduce their emissions is to have fewer children.

[B]

Yep. He found that while living car free saves 2.4 tonnes of CO2 equivalent emissions per person per year, not having a child saves a much, much bigger 58 tonnes per person per year.

[A]

Wow. In comparison, that 58 tonnes seems like a huge figure.

[B]

It's because, Wes, the problem with creating humans is that they are probably going to create more humans. And before you know it, you are partly responsible, along with your offspring, other parent and grandparents, for a long line of polluting, consuming human beings, the result of which is called your carbon legacy. It was calculated by a previous group of researchers. They inputted current carbon emissions, fertility rates and life expectancy into a computer model.

[C]

The model sort of projects one generation of lineage. Maybe one person has a child, that child goes on to have three grandchildren, those grandchildren go on to have five grandchildren, and you add up the total amount of emissions attributed to that whole lineage and then you run the model again and perhaps this next time it goes on for 100 generations. And they run that model 10,000 times and they take an average. And for the United states, the average CO2 emissions is 9,441 tons.

[A]

So each child actually leads to 9,500 tons of carbon. That's not a big. That's a huge figure.

[B]

Yes, that is a figure for American level consumption totalled over many, many generations. But the 58 tonne figure comes from not looking at Americans, but taking an average of all the carbon legacy figures for developed countries and dividing that number by average life expectancy to get to a figure of 58 tonnes. And to put that 58 tonnes figure into perspective, if we want to prevent a rise in global temperatures of more than 2 degrees above pre industrial levels, which is what the IPCC and most climatologists think is a reasonable figure to aim for, if we want to avoid something really, really bad happening, we need to half global per capita per year emissions in the next 30 years or so, from around 5 tonnes to around 2.5 tonnes.

[A]

Okay, but I'm guessing that not everyone is going to agree with the way that Seth's done his calculation.

[B]

Well, first of all, there's a split in the world of academics who look at climate change roughly between those advocating for individual actions like reducing family size, and those looking for a big technological fix, something that will free us from our addiction to fossil fuels. Bjorn Lomborg of the Copenhagen Consensus is in the latter camp.

[D]

I'm somewhat controversial because I do accept that global warming is a real problem and something that we need to fix. But I also insist that we need to focus on where can you do that most effectively. There's something weird going on here because what you're essentially saying is that you are responsible for all the offspring that will come down your descendant line and that adds up to an enormous amount of CO2. There's two problems with that. First of all, it seems reasonable to say that, that you're responsible for your child. But your child's decision on whether to have children or not should be that child's decision, not yours and that child's moral obligation. The second part of course, is it seems very unlikely that children far into the next century will still be emitting say, 15 tons per year, as a rich American is doing right now. Much more likely we will have develop technology that will allow us to reduce our emissions dramatically, maybe even very close to zero.

[A]

So Bjorn's right. Does assuming your kids and grandkids will live in a world where energy is green and clean change the ultimate calculation?

[B]

I asked Seth Winns about that and he said even if your child lives in what the IPCC thinks is a very optimistic account of what the world will be like by the end of the century. Your carbon legacy goes down very significantly. But having kids is still the biggest thing you're going to do to add to global warming.

[A]

We've heard about this kind of thing before, haven't we? The idea that bringing the number of humans down, you know, is going to save the planet.

[B]

Yeah. Most famously of course, was the idea of the population bomb that was espoused by Paul ehrlich in the 70s. He predicted mass famines due to overpopulation in the very near future. Of course that never came to pass and that was because of huge advances in food production, that big time tech fix. So we've got to be careful about predicting these disastrous consequences brought about by overpopulation. The bigger problem though, with using family size as a lever to curb global warming is that it's a very crude way to think about bringing consumption of fossil fuels down.

[A]

Yeah. And I bet it hasn't gone down that well, really, has it? With a lot of people. I should imagine there's been some pretty vociferous opposition there has.

[B]

I spoke to ecologist Corey Bradshaw, he's the person you mentioned at the start of the show, and the academic who's received death threats. That was mainly because he modelled what would happen to the global population if there was a mass extinction event equal to a third world war. People took him for a promoter of human misery. Of course he's not that. He's kindly done a calculation, especially for us. He's modelled what would happen if the global fertility rate dropped from 2.4 children per woman to 2 tomorrow, while moved

[E]

towards 2 children per woman on average globally would end up reducing the population trajectory by about 50% from what it would be going from 13 billion by the end of the century down to something more like what it is today, 7 billion. That only translates into a 7% decline in total emissions from now to the end of the century. We're talking probably in the vicinity of 500 gigatons difference over the next 70 or so years. That's nothing to sneeze at by itself. It won't be enough.

[A]

No, hang on. So if everyone on the planet only has two children, we halve the projected population by the end of the century. Why doesn't it also follow that we lead to a halving of the per capita carbon emissions that we're looking for?

[B]

Because bringing the average fertility rate down actually has very little effect on people in industrialized countries. The birth rate's already low. We get that huge population cut mainly from Africa and other places where the birth rate is at around four or five children per woman. And these people generally have very small carbon footprints. It doesn't even really help if you somehow brought in a global one child policy. Because of the momentum in the system, we just end up with the same number of people alive in 2100 as we have now.

[A]

OK, I've got to ask, do Seth Wins and Cory Bradshaw have children?

[B]

Seth Wins doesn't. Yet Corey Bradshaw didn't mean to because of that individual carbon legacy impact, not because he thinks population control on its own is the answer to climate change. But he accidentally had a daughter, which he is of course very happy about. Seth remains convinced that smaller families is the number one thing you can do.

[C]

Our research is saying if you're interested in making those most important changes, they are having a smaller family, avoiding air travel, living car free eating, a plant based diet. And you know, a lot of people in our society have been doing some of those smaller actions for a long time. They might have been recycling for the last 15 years and they might be ready to say, okay, I've done recycling, I understand how to do that. I'm ready to step it up a notch and do something more for the planet. These high impact actions are a way to do more.

[B]

All our experts agree that population can't be the answer to climate change. The answer has to be reducing the amount of carbon emissions our consumption produces. For Seth and Corey, a big emphasis has to be on individual action. Whereas Bjorn puts his trust in technology,

[D]

individual action on climate change rarely will lead to very much impact because it is a small impact. What really is necessary if you're going to fix climate change is about getting technological change. It is about getting our systems to be much more effective. This is not something that you can typically help do, but this is something that we, through our votes and our influence over politicians, can force them to think more about.

[A]

Bjorn Lomborg there. And thank you to Lucy Proctor. Well, that's all we have time for on More or Less this week, but please keep your questions and comments coming in too. More or [e-mail] Please join us again next week. Until then, goodbye.