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I've edited this essay to respond and incorporate points made by commenters. Thanks to all who have provided feedback.


This is something I see come up in EA social media spaces and I am keen to state an argument against anti-natalism in clear, strong, and persuasive terms. Typically the anti-natalist case is presented as a way to avoid a significant impact on the climate. I think this is flawed: while the average human certainly has net-negative impact on the climate, the average human also has a net-positive impact on total human well-being, simply by existing and leading a net-positive life.

First, let's survey some morally relevant areas that you have control over, and that having children could impact.

You matter

My well-being and yours, and your potential children, all have moral worth. We matter too. If your altruism completely excludes your own well-being, I would be concerned about how sustainable it is. See further notes at the bottom.

Your children matter

Assuming your potential children live average lives, they'll probably experience a lot more happiness than suffering and their lives will be well worth living. The impact that each individual has on the climate is dwarfed by the well-being that person experiences in their own life. These are contestable claims: there are lively arguments over the "total view" vs. the "average view", but I take a total view on this. If you take the average view, you might disagree you should take your potential childrens' well-being into account.

Your own impact on EA matters

Having children will influence your own impact within your career and life on the world. For instance, someone in a particularly impactful career might avoid having children if they think it would lead them to sacrifice making a difference in their career.

In conclusion

If you want to maximize total aggregate happiness in your decision,

- your primary concern should be yourself and your potential co-parent's happiness because that will be massively influenced by your decision - potentially either way, depending on your preferences. Managing own happiness and well-being is an important part of maximizing total aggregate well-being. Therefore, if you don't want to have kids, don't have kids - you don't need climate change to justify that decision!

- Then, as a distant second you should consider the net positive impact your children would experience through living their own lives.

- As an even more distant third priority, think about the impact that having kids would have on your own ability to have an effective career. Now, this may be a persuasive argument against having children for some people. For others, including those earning to give, or people who would simply be less happy not having children, having children might function as a positive motivator that enables you to have a more effective career than you would otherwise.

- In terms of maximizing total well-being, your kids' impact in the climate is a distant fourth relative to all those other concerns I've raised. The magnitude of their impact on the climate is likely to be much, much smaller than any of the three other factors I have raised.



"Is it really true that "effective altruists" should consider their own well-being, too?"

It is true that "altruism" excludes your own well-being by definition. However, a moral system that arbitrarily excludes the agent's own well-being seems arbitrarily selective. Certainly any consequentialist or utilitarian would want to weight their own well-being equally with others.

But this is not just a consequentialist approach. Wider philosophical and religious discourse around morality are also premised on concern for self. The religious command is "Love thy neighbour as thyself", not "Love only thy neighbour, not thyself". Kant's deontological rule is "act only according to that maxim you would have as a universal rule", not "act only according to maxims that would benefit others".

How do we know the negative impact of a marginal individual on climate change is smaller than the positive impact an individual has on their own well-being?

My initial thinking: most of the negative utility of climate change is related to its negative impact on human life. It makes human life somewhat less enjoyable. At its worst, the negative utility of climate change could end all human existence. So there is a scenario in which the negative utility of climate change is equal to the positive summed utility of human existence. However, this scenario is highly unlikely: <1%, and possibly <0.1% (Ord, 2020). So we should strongly downweight the negative utility of climate change.

That said, I think what I've missed here is that the negative utility of human extinction doesn't just cancel out the positive utility of everyone existing now; it is worth the positive utility of everyone who might exist in the future billions of years. So this is part of my argument I might need to reconsider. I'll try to consider this further.





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You might also be interested in John Halstead's and Johannes Ackva's recent Climate & Lifestyle Report for Founders Pledge. They point out that taking into account policy effects can dramatically change the estimated climate impact of lifestyle choices, and on children specifically they say that:

The biggest discrepancy here concerns the climate effect of having children. For the reasons given, we think our estimate of the effect of having children is more accurate for people living in the EU or US states with strong climate policy, such as California, New York, as well as other states in the Northeast. Indeed, even outside the US states with strong climate policy, we think the estimate accounting for policy is much closer to the truth, since emissions per head are also declining at the national level, and climate policy is likely to strengthen across the US in the next few decades.

After taking into account policy effects, they find that the climate impact of having children is comparable to some other lifestyle choices such as living car-free. (I.e. it's not the case that the climate impact of having children is orders of magnitude larger, as one might naively think w/o considering policy effects.)

For more detail, see their section 3.

I agree that blanket endorsements of anti-natalism (whether for climate or other reasons) in EA social media spaces are concerning, and I appreciate you taking the time to write down why you think they are misguided.

FWIW, my reaction to this post is: you present a valid argument (i.e. if I believed all your factual premises, then I'd think your conclusion follows), but this post by itself doesn't convince me that the following factual premise is true:

The magnitude of [your kids'] impact on the climate is likely to be much, much smaller than any of the three other factors I have raised.

At first glance, this seems highly non-obvious to me. I'd probably at least want to see a back-of-the-envelope calculation before believing this is right.

(And I'm not sure it is: I agree that your kids' impact on the climate would be more causally distant than their impact on your own well-being, your career, etc. However, conversely, there is a massive scale difference: impacts on climate affect the well-being of many people in many generations, not just your own. Notably, this is also true for impacts on your career, in particular if you try to improve the long-term future. So my first-pass guess is that the expected impact will be dominated by the non-obvious comparison of these two "distant" effects.)

At $50 per ton cost to sequester the average American would need to generate $1000 per year of positive impact to offset their co2 use. The idea that the numbers are even close to comparable means priors are way way off. The signaling commons have been polluted on this front from people impact larping their short showers, lack of water at restaurants and other absurdities.

I actually think that a true measure of the climate impact of having a child should not just factor in the extra carbon they will be responsible for over their lives, but also the very small probability that they will be responsible for doing something awesome (e.g. "solving climate change"), which may be enough to offset the expected carbon footprint.

(Of course, this only makes sense if you think that the tail positive risk of them doing something amazingly positive outweighs the tiny probability that they will do something stunningly negative!)

Here's my own view:

1. I think the impact on your own career and donations should plausibly go first. Here, your wellbeing still matters, but only instrumentally. You are one person, and if you're impartial, your interests shouldn't outweigh the interests of all of those you could help, who are also probably much worse off than you. The average cost of raising a child seems to be over $200K USD, and through the Against Malaria Foundation or Malaria Consortium, that could save the lives of several people. However, you may be able to raise a child much more cheaply, and if you think you can't be happy without having children, not having children could plausibly be bad for your career impact and donations.

2. If your children donate to EA charities or otherwise contribute to EA (and it doesn't have to be a lot), then they can make up for any negative impacts they would have, and I think this would come second. Maybe they can make up for losses in 1, too.

3. If you're nonspeciesist and your children aren't concerned with their impacts on nonhuman animals, then their effects on nonhuman animals would also come before the wellbeing in their own lives or your life, since they could be responsible for the suffering and deaths of many animals per person at any moment in time, on average/in expectation, mostly through their diets.

Then it's your wellbeing, their wellbeing, and greenhouse gas emissions towards climate change, but I'm not sure in what order.

Thanks. This is a challenging response to reply to. (3) risks "proving too much" but it seems like a valid argument on its face.

I left a related comment here. Specifically:

For example, you'd imagine 2 to 3 chickens and 11 to 12 farmed fishes, in misery, hanging around each human, on average (at any given moment).
You could also imagine each person slaughtering a chicken every ~40 days and a farmed fish about once a month.

This is the global average, and the vast majority of farmed chickens and fishes are factory farmed. The numbers should be at least a few times higher in developed countries on average, since animal product consumption is higher. On their welfare, see this report, which of course involves subjective judgements.

In developed countries, usually at least 20 farmed land animals are raised for food per person per year on average.

Here's a half-baked argument for natalism vis-à-vis climate change:

Carbon emissions in the highly developed countries most EAs live in are generally trending in the right direction (i.e. there seems to be at least relative decoupling between emissions and consumption). The bulk of emissions growth over the next several decades will be in other large, rapidly developing countries like India and China. Green technology transfer is a way that highly developed countries can positively influence emissions in the critical rapidly developing countries (see e.g. this). Economic models generally propose that a larger population generates more ideas and a higher rate of technological change (e.g. Population Growth and Technological Change: One Million B.C. to 1990). Therefore, the (smallish?) direct impact of increased emissions from greater population in highly developed countries might be outweighed by more green technology and technology transfer to the crucial rapidly developing countries like China and India.

your primary concern should be yourself and your potential co-parent's happiness because that will be massively influenced by your decision - potentially either way, depending on your preferences

why do you believe that? (intuition is a fine answer, but I think it should be made explicit)

Managing own happiness and well-being is an important part of maximizing total aggregate well-being

do you mean because being more happy will directly increase the total amount of happiness, or do you mean being happy will make you more effective at work? (I think it's important to disentangle both of those)

Then, as a distant second you should consider the net positive impact your children would experience through living their own lives.

why "as a distant second"?

The magnitude of their impact on the climate is likely to be much, much smaller than any of the three other factors I have raised.

how do you know that?

it seems to me like that's a lot of claims that aren't backed by anything

might also be worth considering the other indirect impact of having children

Yes, I tend to think that any one individual's impact on the world around them probably balances out roughly neutral.

So I don't use the argument that your own children might do a lot of good for the world and therefore you should raise children. That seems too speculative. And so the more known direct impact of having children on your own happiness and their happiness balances out the very speculative, almost entirely uninformed prior of the indirect effects having children might lead to.

Where you have a clear idea of a high and direct impact career that would be difficult to pursue were you to have children, then yes that might win out. Again, direct impacts are important, indirect impacts I think are so speculative that they probably don't count for much.

As for earning to give, this is another challenge to my argument. I am sceptical that someone who really wants to have children will be happy in the long term sacrificing that for earning to give and this I'm sceptical that their commitment will be sustained and thus it may not be particularly impactful anyway, vs some compromise between personal desires and earning to give that is sustainable over decades.

That's pretty speculative on my part but maybe borne out by observations made by 80k on people who enter morally neutral, high impact careers just to earn to give.

From a total view, I think this does outline a potentially compelling case against the climate change argument, but I don't think it's compelling from an average point of view. Even from an in-between perspective (which I think roughly represents my feelings) which evaluates overall welfare as the product of average quality of life times the square root of population, it seems that marginal hits to the climate may outweigh marginal gains in quality of life.

Even from a totalist POV, it's important to consider lives with negative value. It matters where the line is drawn- some people may feel all lives have positive valence, others may set a high standard, and say that a life with positive valence must have very little suffering, even an absence of suffering that may be fairly unheard of in modern life. By having children, you might increase the value that your life contributes to overall welfare, and contribute the lives of your children, but have an impact on many people which changes their lives from making a positive contribution to a negative contribution, or greatly increases the suffering of a person who already has a negative-valence life.

This certainly isn't to say that I think you're wrong - I think the structure of your argument may be usable to make a compelling case which addresses my concerns, and in general I do feel (though am not certain) that on net, the average person will contribute more to other's well-being than they take away.

"Assuming your potential children live average lives, they'll probably experience a lot more happiness than suffering and their lives will be well worth living."

I think this is assuming a lot. The point of not having progeny in the climate change argument, is to preserve the possibility for other humans to have such happy lives. Having progeny, in that argument, is what actually challenges this assumption. It is problematic to argue that average happiness within rampant climate change will be higher or lower than average suffering. But what it is plainly wrong is to argue that they won't be substantially worse than today.

For me, your argument reads very similar to something like: it is fine that you cut more trees than your share (share being calculated so that new trees can replenish the forest) if the happiness gained is large enough. Well, this is fine until there are no trees left. In other words, it very much seems like an example of tragedy-of-the-commons-thinking.

A different issue is whether or not having progeny exacerbates climate change, but this is not what you challenge.

Interesting, appreciate your reply! I think you raised a couple of concerns:

  1. Bringing an additional child into the world results in them essentially taking from a limited resource (the finite share of carbon emissions that can be captured, mitigated, or tolerated), reducing the resource available for everyone else.
  2. It's plainly wrong to argue life won't be substantially worse than today

Have I understood your argument right?

I think (1) is complicated. Even if it's true that bringing an additional child into the world results in less for everyone else, the primary beneficiary isn't the parents of the child, but the child themselves (although this depends on whether you take a "total view" or "person-affecting" view of population ethics. It's true under the total view, which is my own perspective. If you take the person-affecting view, you could disagree). The key point I was trying to make in my post is the benefits accruing to that one child are greater than the total sum of harm that additional child does by existing and producing a carbon footprint. I think other commenters were right to say I haven't made a strong affirmative case, but at least, I'd appeal to you to consider whether the calculations need to be done.

I'll attempt a brief calculation, though. I don't necessarily stand by these figures, but my point is that (from a consequentialist point-of-view) doing a calculation like this is important for understanding whether anti-natalism is a good response to climate change.

The largest impact of climate change on human beings in expectation seems to be forcing people out of their homes and communities to migrate, possibly across thousands of miles to different countries. Many will die of famine, thirst, or other acute problems, but all have their lives uprooted. Understanding the number of people this will impact is difficult, but the best estimate I can find is roughly 200 million. If this scales linearly with the number of people in the world, roughly 8 billion now, then for every 40 new people in the world, we'll have 1 new climate refugee. Is it worth coming into the world if you have a one in forty chance of being a climate change refugee, or causing someone else to be? Of course no one can actively make that choice, but we can make that choice for someone "in expectation" if we're in a position to decide whether to bring them into the world. To me a 1 in 40 chance of a bad outcome is worth a 39 out of 40 chance of a good outcome.

But even though that still seems a worthwhile gamble, in reality, I think the situation is much, much less dire than that. The impact of climate change won't scale linearly, because as we get more people, we'll spend more resources on carbon capture and transitioning to a zero emission economy. This does impose costs on people, but the sacrifice of driving a bit less, or spending a bit more money on solar panels, or other forms of getting to carbon zero, seem less of a sacrifice than not existing at all. This isn't completely obvious, because the burden is across the whole of society, but I'll have to leave that exercise for the future.

For the second point (2): people have done their best to work out the economic impact of climate change. The best indications are in the range of 2-10% of world GDP. On average, the US and other developed economies grow about 1-2% a year, or 10-20% a decade. So the impacts of climate change, and responding to it, will cost us a decade of growth and rise in living standards,. But, overall, it seems like living standards will still be higher in future than they are now, even accounting for the impact of climate change.

Have I understood your argument right?

Yes, but 2 applies to rampant CC (climate change) and 1 within the CC argument.


If I understand it right,  your reply challenges the idea that the net effect of having progeny is exacerbate CC, at least in the long run, which I thought you deliberately intended not to do in the post. I think this is a completely different argument, one that I don't want to go to because it lacks any end: CC is a continuum, its effects are not linear, tipping points are not well understood, its effects will knock-on other effects, it all depends on technology and infrastructure (effective EROIs from alternatives to fossil fuels are lower than we could wish, it is at least very hard to change the infrastructure of the whole society to accommodate a complete change in energy sources, carbon capture and storage at scale may be possible or may not...), unknown unknowns...

I guess my central point was that you cannot argue that CC should not be a significant factor deciding on having children or not (if you care for total happiness), without arguing whether having children is something that will effectively exacerbate CC in the long run or not. And I think you were trying to do that.

If having children does effectively exacerbate CC in the long run, even if its effects in the happiness of the very next (few?) generation(s) may still be net-positive, in the long run this is overwhelmingly negative (in the far off limit, Earth is like Venus). If having children does not effectively exacerbate CC in the long run, there is no debate. And everything in between (now it does but later not, it does but up to a certain point, it does but actual human population will decrease...) is a hugely messy debate.


BTW, the GDP calculations are useless without knowing its assumptions. And if they come from Nordhaus, his calculations seem to be really, really bad, with utterly unrealistic assumptions.  Things like calculating the differences in GDP of regions with, XºC average temperature difference and extrapolating it to CC without accounting, for example, that many regions on Earth will be inhabitable if their average temperature increases XºC. Note that, although he's got a Nobel price for it, basically no one in fields related to sustainability research (except for some economists, I guess) accept them.

Some great points, and you've got me thinking again, honestly. I'll concede that if the GDP impact or human life impact were quite a bit different, and they absolutely could be, I'd be...at least thinking a lot harder about this.

I guess my central point was that you cannot argue that CC should not be a significant factor deciding on having children or not (if you care for total happiness), without arguing whether having children is something that will effectively exacerbate CC in the long run or not. And I think you were trying to do that.

That a fair criticism. Trying to sum up, I think the point I'm trying to get across (poorly expressed in my OP, I have to say) is that 

(1) one should (under a total view of happiness) include the enjoyment one's potential child will get out of life in the calculations

(2) the enjoyment one's potential child will get out of life is almost certainly still positive, and 

(3) to make a new person's existence net-negative, the marginal impact of climate change of an extra person would have to be large to outweigh the total utility of an extra person living, say 40-80 well-being adjusted life-years. While we can all see the impact of climate change as a whole is large, that is the combined impact of 8 billion people; the individual impact of each marginal person is much smaller than the WALYs they experience through existing.

On my understanding of impacts, I had thought (2) and (3) would be uncontroversial given the evidence. Thus, I mainly wanted to point out the analytical argument outlined in the previous paragraph, and that would be enough. But now you've told me true GDP impact could be much greater than 10%, I'm much less certain about that! I guess you are right at least that the debate is "messy".

Do you have any sources you can recommend that contain more reliable estimates of (a) GDP impact, (b) human life impact, or (c) long-run exacerbation where things become "overwhelmingly negative"? All of that would concern me, particularly the long-run overwhelmingly-negative scenario.

I understand this is getting into an entirely new argument I didn't make originally, so appreciate if you don't want to stray, but at some point, I think the "climate cost" to grow the population by some amount is the lesser of the mitigation of their carbon footprint by other means, or the actual effects of their carbon footprint. That makes the assumption that "we" (whoever the imagined "we" is) will choose the lesser cost option, which is problematic, but on the other hand, I'm not sure how much moral responsibility you can build into the choice to have a child if a less impactful alternative to mitigation exists which society as a whole chooses not to pursue.

Hi. Thinking about it, I probably overstated a bit about Nordhaus' acceptance. Instead of saying "basically no one in fields related to sustainability research" I think "many do not" is probably more accurate. I'm in my bubble and there may be very different bubbles around. And I guess a bad model is better than no model, as one can improve it instead of starting from scratch.


About what you ask for: 

(a) I'm not sure. Steve Keen (@ProfSteveKeen in Twitter) is very vocal about how bad Nordhause's model is, maybe he's got something. But (rightly) pointing that something is wrong is much easier than building something better, so I'm not sure if he's got anything. I know he was working on one (several?) paper(s) with Tim Garrett. But Tim is physicist, so it may be something beyond GDP (Tim has a model showing that CO2 emissions energy demand correlates very well with historically cumulative GDP somehow implying that we are actually not decoupling from resource needs). 

In general, the problem is that any meaningful CC will have knock-on effects that are ultimately impossible to predict. One can put numbers on those, but then for each Temp there have to be at least different scenarios (only Temp, plus X damage from more extreme environmental phenomena, plus Y effect of war, plus Z from migrations, combinations, degrees...). And on top of that, there are unknown unknowns (e.g. last summer hat heatwaves that melted infrastructure in some parts of the US [I think], which AFAIK basically no one had predicted).


(b) and (c)... maybe the people in the SCER and in the Global Catastrophic Risk Institute? These folks study knock-on effects that CC could produce. Beard from SCER spoke about it in the FLI podcast and I think Luke Kempt also has worked on related topics. I'm less familiar with the people in GCRI. But in general, these all look at overwhelmingly-negative scenarios (CC triggering a nuclear war and so on), so it sounds like what you want.


I hope this helps.


I find the ethics of procreation to be incredibly complicated. While I am skeptical of some of the particular arguments of this post, I agree that there are reasons to suspect that procreation is either morally good or morally neutral. Although I have substantial uncertainty about the moral goodness of procreation, I do strongly believe that many talented and altruistic people will be driven away from the EA community if anti-natalism becomes a big part of the cultural attitude. Many if not most people react to anti-natalism extremely negatively. They take it as an affront to their most personal choices, an insult to the people they most care about, and sometimes even a dangerous ideology that they inexorably associate with horrific human rights abuses. If there were real reason to believe with confidence that one of the best ways we can do good is lower the birth rate of people who actively want children, then that would be one thing. However, that seems so so so far from the current reality, that focusing on anti-natalist efforts just makes EA (or whatever other cause/group) look bad.

Great to put the climate externality of a child explicitly in relation to other positive and negative values that come with having a child. Thanks for doing this and doing it so well.

A question: where else in the population ethics debate can I find the kind of reasoning that you employ? More specifically, where else can I find (1) lists of the bazillion positive and negative externalities of an additional child and (2) some argument -- however weak -- that takes us beyond agnosticism on the question whether an additional child is overall a *net* positive or negative externality (and, in case it is a net negative externality, where can I find some argument -- however weak -- whether it is *sufficiently* net negative so as to outweigh the value that the life has to the child itself)?

PS: I've laid out 9 further reasons (plus a version of the point that you make) why the initially appealing case for less children here is surprisingly unclear at closer inspection: https://twitter.com/dominicroser/status/1228295710740766721 I've grown convinced that the climate case for less children is much more difficult than people think and think it's important to highlight this fact.

More specifically, where else can I find (1) lists of the bazillion positive and negative externalities of an additional child and (2) some argument -- however weak -- that takes us beyond agnosticism on the question whether an additional child is overall a *net* positive or negative externality

Hello Dominic,

I do something of this in my DPhil thesis in chapter 2. I'm pretty uncertain whether the Earth is under- or overpopulated whatever one's views on population ethics.

Thanks for this, Michael! I will look at it.


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