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Speak no evil, hear no evil, see no evil

Obstacles in Path to Sustainable Population

This is installment 6 of questions from our Solving Overshoot webinar. I’m sharing questions we didn’t have time to address and  including comments received from Madeleine Somerville and Paul Ehrlich, our panelists. If you missed the first few installments, start here with installment one. Your comments are welcome below. If you don’t want to miss our next webinar, your best bet is to join GrowthBusters. At the very least, subscribe to our email updates. Once again, population dominates the discussion.

20. Bruce Phillips asked: “Are there any population narratives that would unite the political left and right?”

Paul Ehrlich: Don’t know of any except the bare facts, which seem to have no influence.

Madeleine Somerville: The challenge seems to be the right’s adherence to religious doctrine which forbids contraception and abortion and invites their followers to be fruitful and multiply. Pair that with climate-change skepticism and it doesn’t seem too hopeful. 

21. Anonymous Attendee asked: “At what population could we sustain ourselves indefinitely, assuming our lifestyles do not change? Is it even possible for us to sustain ourselves indefinitely considering our current lifestyles?” Possibly around 2 billion (Daily GC, Ehrlich AH, Ehrlich PR. 1994. Optimum human population size. Population and Environment 15:469-475.)

Madeleine Somerville: According to one ecologist, E.O.Wilson, if we wanted to live like the typical North American, the earth could comfortably support 200 million people. [source:]

Dave Gardner: The serious scientists who’ve studied this all have given us answers below 4 billion. So we know which direction we need to head. We’re told a world population of 2 billion would need to be living like Europeans, not North Americans.

22. Grant Barnes asked: “What is likely to be the curve of U.S. population this century? Do you agree with The Tyndall Centre’s Kevin Anderson that there will be fewer than 1 billion worldwide by 2100?”

Paul Ehrlich: If Anderson is correct there will be a “death rate” solution to the population problem – with more than 6 billion people dying prematurely.   Possible, depends on what kind of collapse occurs.

Dave Gardner: I do think it is highly unlikely we’ll hit the numbers in the United Nations mid-range scenario (about 11 billion). The green revolution is doing too much damage and can’t be sustained, let alone reinvented. Ocean dead zones, phosphorous and fertile soil depletion, and the pumping dry of aquifers and major rivers do not bode well for even 7 billion to be alive in 2100 (not to mention climate disruption).

23. Oscar De Uriariye asked: “Dr. Paul.  Why do you think environmental leaders rarely speak about overpopulation issues as a key to solve environmental problems, eg. climate change, biodiversity loss, pollution?”

Paul Ehrlich: Fear they’ll turn people away from environmentalism, ignorance of I-PAT, and sometimes pure cowardice.

Dave Gardner: I think more than anything else, it is their need to bring in as much financial support as possible. They fear that taking a position on population will turn off many donors and foundations. Their assessment may be correct. If so, we need to change that, through more and more intelligent conversation and information.

The final installment in this series is here.

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Comments (5)

  • Avatar

    David Lruse


    Maybe left and right could agree of eliminating the personal tax deducting that President Trump wants to do. Anything we can do to eliminate benefits that encourage large families would seem good.

    Health insurance premiums should go up for each child in a family.


  • Avatar

    Karen Pitts


    Contraception usage is high among women of all Christian faiths (Guttmacher), so the ‘Go forth and multiply’ mandate is rarely followed. The ultra conservatives (particularly patriarchal men) see and feel threatened by the breakup of the American family, and they blame promiscuity brought on by the use of contraception. What they don’t see is that, if effective contraception were available to every sexually active young person, there would far fewer unwed mothers and less reason to get married before ready, and therefore fewer broken marriages (Sawhill). If they can be convinced that pregnancy prevention is far more practical than chastity, then we can break this barrier. But don’t tell them it’s to control population. These people are climate change deniers, not inclined to understand the impact of human numbers.


  • Avatar

    Robert Bériault


    I think human ingenuity will allow us to continue to grow our food production, population, industrial production and the wonders related to the iphone and the self-driving car until most of the planet has turned into a desert. I realize that collapse could arrive suddently, anytime, but my guess is that the party will last another 100 years.

    As for what is the optimal, sustainable population, I think there is none. As soon as an industrialized society needs non-renewable resources for its survival, it will meet its demise when they run out.


    • Avatar

      Dave Gardner


      That’s very interesting, John. I had no idea.


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