TED Conversations

Hans Rosling

Director, Gapminder Foundation


This conversation is closed.

Why do so many think that population growth is an important issue for the environment? Don't they know the facts of demographics?

We face many environmental challenges, but the foremost is the risk for a severe climate change due to CO2 emissions from fossil fuels.

I meet so many that think population growth is a major problem in regard to climate change. But the number of children born per year in the world has stopped growing since 1990. The total number of children below 15 years of age in the world are now relatively stable around 2 billion. The populations with an increasing amount of children born are fully compensated by other populations with a decreasing number of children born. A final increase of 2 billion people is expected until the world population peaks at about 9 billion in 2050. But the increase with 2 billion is comprised by already existing persons growing up to become adults, and old people like me (+60 years). So when I hear people saying that population growth has to be stopped before reaching 9 billion, I get really scared, because the only way to achieve that is by killing.

So the addition of another 2 billion in number constitutes a final increase of less than 30%, and it is inevitable. Beyond 2050 the world population may start to decrease if women across the world will have, on average, less than 2 children. But that decrease will be slow.

So the fact is that we have to plan for a common life on Earth with 7-9 billion fellow human beings, and the environmental challenge must be met by a more effective use of energy and a much more green production of energy.

The only thing that can change this is if the last 1-2 poorest billion do not get access to school, electricity, basic health services and family planning. Only if the horror of poverty remains will we become more than 9 billion.

So my question is: Are these facts known? If not, why?

It is important because placing emphasis on population diverts attention from what has to be done to limit the climate crisis.


Showing single comment thread. View the full conversation.

  • thumb
    Feb 16 2011: Global demographics can get pretty complicated. I recently curated a link suite on an aggregator I edit that riffed off of Ted Fishman's new book, "A Shock of Gray: The Aging of the World’s Population and How it Pits Young Against Old, Child Against Parent, Worker Against Boss, Company Against Rival, and Nation Against Nation" (overview post: bit.ly/eHkpWS) Clearly, it isn't only a matter of numbers, but of skews as well.

    However, there is a related question I have wanted to ask you for some time, so will seize the moment... Your wonderful data visualizations show an optimistic trend for global public health. However, although the lot of the human species overall has improved over the last few hundred years, we are in the midst of what has been termed the "Sixth Great Extinction." Thousands of other species have either gone extinct or are on the edge either as a direct or indirect result of human action, including population growth (background: www.guardian.co.uk/environment/2009/jul/28/species-extinction-hotspots-australia)

    Both ethically and from a "one health" perspective, this is an extraordinarily troubling development, one that greening up the energy supply and slowing global warming doesn't begin to address. Focusing on the human-centric public health component, the loss of a these species, both plant and animal, means a loss of bio-filters that keep pathogens in check. Even without extinction, habitat loss can have direct human health consequences (see deforestation & malaria: bit.ly/aPMRuB)

    I would be really interested in seeing data visualizations on public health that looked at the larger fabric / context. I suspect it would reveal significant vulnerabilities. At what cost have the improved metrics of human health come? And given big picture trends, are we at risk for a dramatic reversal?

    Thank you...
    • Feb 17 2011: Janet - that's a good point. Maybe it's hard to shed this sense of impending doom because so many living species do face genuine doom.
    • thumb
      Feb 18 2011: Janet, but what could have been made different during the last 40 years. The number of births have come down, only in the last billion, mainly in Sub-Saharan Africa are we still waiting for the 2 child family to become norm, That is already norm in 80% of world population. From now on the growth will mainly be the already adults growing older.
      And if all of Africa follow in the global trend we can see human population start decreasing from 2050 but that will not be so fast we will most probably be at least 7 billions by the end of 2100. And most of the big threats to biodiversity and climate will happen before 2100. And yes active and successful poverty alleviation and family planing can make us peak at 1/2 billion less . I can not understand what else can be done to reduce the number of humans, except th unthinkable, a mega holocaust! I do not here any realistic suggestion from those concerned by human numbers.
      • thumb
        Feb 18 2011: Hans, thank you for your response. I think we may be talking past each other though. I am focused not so much on what could have been different over the last 40 years, but more on the implications for human health over the next 40. Although your data visualizations are very compelling, the focus is on a set number of public health metrics. I am suggesting that those be placed within larger contexts to analyze vulnerabilities.

        Much has been written about the emergence and re-emergence of dozens of zoonotic infectious diseases over the last 30 years . These illnesses not only have potentially significant direct impact on human health, but indirect impact vis a vis livestock. Meanwhile, plant crops are facing a resurgence of traditional scourges, including wheat rust, the original Green Revolution's public enemy #1.. GMO crops are starting to experience resistant "superweeds." Deforestation, urbanization and increased trade/travel have all worked in favor of spreading pathogens far, wide and fast. Now, two new studies suggest a link between wacky weather and man-mediated climate change (by no means definitive but part of a growing chorus: ecocentric.blogs.time.com/2011/02/17/new-studies-show-that-climate-change-is-the-culprit-in-extreme-rain/). Recent weather—floods & droughts—whether or not climate-related, have taken such a toll on commodity crops that we're seeing food cost price hikes in the neighborhood of 30%.

        So what does all this mean going forward for global public health?

        Beyond the appalling truth that one species can cause the extinction of so many others—we're right up there with meteors in the extinction-event derby—what do all these trends mean in terms of human health /population growth?

        Some new data visualizations, please...

        thank you...
        • Feb 18 2011: I agree with Janet, loss in biodiversity, land degradation and encroachment have increased the number of emerging infectious diseases (75% of which are zoonotic). Further, the impact of livestock and crop production increases the risk of food insecurity as well as decrease in individual economic development.

          As far as the demographics go, I would be interested in more focus on regional data, instead of overall global rates. Are the areas where population (i.e. births) increasing, also areas of limited/degraded land, decreased animal/crop production, poor nutrition, etc. What are the public health infrastructures like in these areas? Many of these regions are also hotspots for emerging diseases. In other words, the total global population density might not be the issue; instead, it might be more enlightening to look at regions of population growth and whether they also suffer other factors (e.g. food shortages, decreased production, poor public health infrastructure, education, etc.) that would make them significant to the global community.
      • thumb
        Feb 18 2011: H'mmm, I can't "reply" to Craig's comment directly, but wanted to include a link to a map he flagged to my attention that was published in "Nature" a couple of years ago, charting emerging disease hot spots. The focus is on the twin plagues of infectious diseases and drug resistance. www.earth.columbia.edu/articles/view/2033

        It is intriguing to think how this sort of data might be woven into public health data to create predictive models.

Showing single comment thread. View the full conversation.