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Is the Public Ready to Consider Carbon Footprint in Family-Size Decisions?

This question is finally on the table here at GrowthBusters, as I’ve observed mainstream media finally giving ink and airtime to the heavy environmental impact of each additional child brought into the world. Why is that?

One reason is that scientists have now documented choosing to conceive just one fewer child will reduce your carbon footprint a LOT more than any other “green” action. You’ll find that study VERY interesting. It’s bottom line: “until the emissions associated with desired services are reduced to zero, population will continue to be a multiplier of emissions.” Multiplier is the key word here.

That ought to be a “duh” statement, but – until recently – overpopulation was rarely mentioned, and DOING something to ease human population back to a wise and sustainable level was never mentioned in the scientific reports or news coverage of climate change. But that is finally changing.

This information, and the question heading this post, inspired us to do a few things:

  • Test this hypothesis in man-and-woman-on-the-street interviews for our World Population Day video
  • Make this the topic for our August GrowthBusters webinar
  • Conduct a brief survey to gauge public knowledge and attitudes

Before I get into the details of these, if the media coverage of the issue is news to you, these commentaries at Growth Bias Busted will get you up to speed:

NPR Illuminates Important Conversation About Kids

Bill Nye Actually Discusses Planet-Saving Policy

One Action Reduces Your Carbon Footprint 100 Times More Than Driving a Hybrid

Ignorant Response to Good Reporting on Climate/Family Size Connection

Now, the details…

World Population Day Video – we kept this video very short, so it doesn’t give you a good sense of the overall response. I was a bit surprised that almost no one I approached expressed any offense at having a conversation about the link between family size and carbon footprint. This is very good news.

GrowthBusters Webinar – because bioethicist Travis Rieder has been such an articulate and positive spokesperson for this issue, I invited him to be our guest for the webinar, Fewer Children: A Moral Responsibility. The video replay of this webinar will be available for another week. After that, it moves to our webinar archive, available to all supporting members of GrowthBusters. (A very modest $7/month gets you access to all the webinars, plus a discount on growthbusting tools at our store, and more. Membership details here.)

 Public Knowledge/Attitude on Climate/Family-Size Connection – Leading up to the webinar, we ran a brief survey to gauge the level of knowledge and to further test our hypothesis that people are finally ready to talk about conceiving fewer children in order to have a hospitable climate.

We actually ran the survey twice – we gave one survey link to those subscribed to our GrowthBusters email updates, and we publicized another more generally on social media. We did that to see if the general public isn’t as far along this curve as those with a more intense interest in GrowthBusting. Of course we did not have a truly random, scientific sample, so the “public” results are still a bit skewed through self-selection by more enlightened or concerned participants.

Here are the results for both groups:


Q1 Though fewer members of the “general public” were “very concerned” about climate change than members of the GrowthBusters crowd, I was still impressed to see both groups were above 80%.


Q2 Here it was good to see that conceiving one fewer child was rated by both groups as the most effective action in reducing carbon footprint. Also interesting to note that giving up your car was neck and neck with giving up meat among the “public” but that plant-based diet slips to third among the growthbusting crowd. Turns out, according to the best study so far of the impacts of these actions, giving up the car is yields about twice the carbon reduction as giving up meat.


Q3 First of all, I regret that I worded this question so poorly. It should have read that conceiving one fewer child is more than 20 times as effective as the 2nd place strategy. The results are still relevant, however. I’m surprised this surprised no one from the general public in our survey, while it did surprise 4% of the growthbusting group. I have no explanation for this.


Q4 Since many of these questions are truncated in the graphics, here are the complete descriptions of feelings:

  • This is exclusively a private subject; it should not be discussed
  • Everyone should consider this, but it’s not appropriate for anyone else to suggest or recommend
  • Suggesting or recommending fewer children is perfectly acceptable
  • Suggesting or recommending fewer children is important and should be more prevalent
  • We should implement incentives to conceive fewer children and disincentives to conceive more children
  • We need strict laws limiting the number of children per parent

Very glad to see no one from either group was offended that the carbon-footprint/family-size link is being presented. I do find it interesting that a slightly larger percentage of the public believe we need strict laws limiting the number of children per parent. This topic was addressed briefly by Travis Rieder in our Fewer Children webinar, and we’re in the process of planning another webinar that might dig a little deeper into the debate over this one. I think IF it’s necessary, we’d need much better and more widespread understanding of our overshoot predicament in order to avoid immediate, blanket rejection of any such proposal.


Q5 The results were pretty similar here for both groups. I must admit I’m thrilled to see over 70% either have limited or plan to limit their family size in order to cut their impact. I’m pretty certain, however, that a truly random public sample would not return this result.

Changing that is one of our highest priorities here at the GrowthBusters project. I remain convinced that nearly all couples the world over, armed with the facts about the impacts of their family-size decisions, will make the most loving, compassionate decision they can – to conceive just one child.

To be clear, we’re so far into overshoot that I don’t advise you stop at making the ultimate green decision to have a small family. Here’s a chart from the research study that quantified the power of that procreation moderation decision:

And here are a couple of interesting facts from the study:

Eating a plant-based diet saves eight times more emissions than upgrading light bulbs

A US family who chooses to have one fewer child would provide the same level of emissions reductions as 684 teenagers who choose to adopt comprehensive recycling for the rest of their lives.

There are plenty of CO2-reduction plates on the menu– something for everyone. We need more of us, choosing more items.

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Comments (6)

  • Avatar

    Brian Cady


    Kids deserve the best – Having less kids allows us to give each of them more of the best.


    • Avatar

      Dave Gardner


      Very true, Brian. Very true. This is our prime responsibility. The intergenerational golden rule.


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    Paul Potyen


    Excellent and informative. Keep up the good work!


    • Avatar

      Dave Gardner


      It’s great to get the positive feedback, Paul. Thankyou.


  • Avatar



    Finally! Population Pressures is being addressed as a major contributor to environmental problems!


  • Avatar

    Sarah Bexell


    Wonderful and critical work, Dave and team. In fact, I think it is THE most important kind of initiative needed today. Thank you!


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