Paul Murtaughis a professor of statistics at Oregon State University, and he has brought his number skills to bear on environmental issues with papers like, “The Statistical Evaluation of Ecological Indicators,” and “Performance of Several Variable-Selection Methods Applied to Real Ecological Data.”

..The big bulge in our carbon footprint. (photo credit http://www.flickr.com/photos/mujitra/3274279516/ )

When he and M.G. Schlax published “Reproduction and the Carbon Legacies of Individuals” in 2009, he found out what a hot button reproductive issues can be in this culture.  He was labeled anti-birth and skewered in rabid blog after rabid blog.

His paper said:

“Here we estimate the extra emissions of fossil carbon dioxide that an average individual causes when he or she chooses to have children. The summed emissions of a person’s descendants, weighted by their relatedness to him, may far exceed the lifetime emissions produced by the original parent. Under current conditions in the United States, for example, each child adds about 9441 metric tons of carbon dioxide to the carbon legacy of an average female, which is 5.7 times her lifetime emissions.”

“It was amazing the reaction we got in the blogosphere,” Murtaugh said Thursday when presenting his data at the University of Wisconsin-Madison Nelson Institute’s Weston Lecture Series, co-sponsored by the WAGE Governing Global Energy Collaborative.  “People called to threaten me at home.”

“None of the environmental groups would touch this subject,” he continued.  “President Obama was asked, but wouldn’t comment.  This is a touchy issue.  When people feel their freedom to reproduce is being restricted, they respond intensely.” Interestingly, Murtaugh never suggested anyone compromise their reproductive freedom.  He simply presented a numerical analysis.

Not all kids carry the same carbon foot print as babies born in the U.S. (photo credit http://www.flickr.com/photos/vipez/2776453432/

What Murtaugh and Schlax have done is calculate the consequences in tons of carbon of every visit by the stork, and the storks have been busy these past 50 years.  The world’s human population has more than doubled, from 3 to almost 7 billion.  And carbon emissions are climbing too.

Murtaugh studied several of the carbon footprint calculators available online.  They all ask how many miles we put on our vehicles per year and whether we recycle our plastic – but Murtaugh felt there was a crucial piece of the puzzle missing so he set out to calculate how many tons of carbon will be tossed into the air by our children and our children’s children and their children over a period of 500 years.  You see, a decision to have a child sends a multiplicative ripple forward through time, resulting in many more humans adding their own carbon footprint.  And while this fact is unassailable, the ethical implications can get complicated.

Here’s what Murtaugh found about ways to cut your lifetime carbon footprint:

Actual Carbon Dioxide saved (in metric tons)

Recycle newspaper, magazines, glass, plastic and aluminum cans – 17

Replace old refrigerator with energy-efficient model – 19

Replace 10 incandescent light bulbs with energy-efficient ones – 36

Replace single-glazed windows with energy-efficient windows – 121

Reduce miles driven from 231 to 155 per week – 147

Increase car’s fuel economy from 20 miles per gallon to 30 – 148

Reduce number of children by one – 9,441

Data is derived from U.S. Environmental Protection Agency’s personal emissions calculator and calculations by OSU statistics professor Paul Murtaugh. Annual totals were multiplied by 80, to reflect life expectancy of a woman in the U.S.

That is a very heavy trip to lay on everyone of reproductive age who has not yet started their family.  And of course, it’s much more complex than any cut and dried numbers can describe.

I’m going to be mulling on this for a while as I continue to drive as greenly as possible (see my post Idle Thoughts – Turn the Damned Thing Off   and 10 Ways to Cut Gas costs and Save the Planet ), turn down my thermostat, eat locally and use my bike to get around town.

How many kids do you have or do you want?   

Should our choices be tempered by Murtaugh’s analysis?  Talk about a hot button issue! 

But just because it’s awkward won’t make the issue go away.

6 replies

  1. I have three children, and between us we live in three different countries which makes our visits not exactly environmentally friendly.

    As you said though the statistics are not the same for everyone and will greatly depend on how much is invested in the little one. Reusing baby equipment and clothes instead of getting new each time will make a vast difference. Not taking them to every possible activity they can go to by car will also make a difference.

    We still need children for the future but how we bring them up will affect the earth and its balance. Bringing them up to tread more lightly on this earth and not to expect endless money to finance lavish lifestyles would be good

  2. Yes, we do need a next generation. I know I appreciate my children and nieces and nephews enormously. (no generation beyond that yet) And I agree that raising them to understand environmental realities and shape their lives accordingly is the best option.
    What worries me is that the financial powers see more humans as more profits. Their equation is keep the economy growing by keeping the population growing. It is very short sighted and selfish.
    When I think of the relatively clean, clear world I inherited and the crowded, toxic, over heating world I am leaving to my offspring, I don’t feel good.

  3. I echo what Joanna said about teaching our children to tread lightly.

    In addition, I see nothing wrong with being responsible for how many lives we bring into this world. There was a time when large families were essential for survival, but not anymore. While I would never advocate laws limiting our rights to reproduce, it would be nice if we could teach our children more about the responsibilities of reproducing.

  4. Absolutely, Lorijo!
    I don’t think anyone would advocate taking away one’s right to have children that one has thought about, is prepared for and truly wants.
    What worries me is the constant efforts on the part of several large movements in this country the are actually driving the number of unwanted pregnancies up.
    When we now have numbers on the environmental ramifications of each birth, it makes unwanted pregnancies seem especially unfortunate.

  5. No kids and no plans for kids. I just don’t view the current population to be sustainable and can’t justify making myself an exception to my beliefs.

    To those who do want children but are worried about overpopulation–adoption is something to consider.

    • Yes, it’s a very complex question. I agree that adoption can be a great answer. I have friends who have adopted. My quandry with adoption — without having researched this at all — is that it seems to take a lot of money to adopt, and I wonder what kind of financial help is available to those who want to adopt but don’t have that kind of cash. It would be neat if insurance would cover adoption the way they cover giving birth, but I suspect that it does not.

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