In the middle of an article defending the child-free lifestyle, Lisa Hymas notes:

If you consider not just the carbon impact of your own kids but of your kids’ kids and so on, the numbers get even starker. According to a 2009 study in Global Environmental Change [PDF] that took into account the long-term impact of Americans’ descendants, each child adds an estimated 9,441 metric tons of CO2 to a parent’s carbon legacy—that’s about 5.7 times his or her direct lifetime emissions.

I don’t begrudge anyone the child-free lifestyle. I like the kid thing but it’s not for everyone.

But this particular child-free argument falls flat for me. I’ve pointed out before that we need future generations of smart people to solve our ecological problems. And smart people, while not guaranteed to have smart kids, are more likely to.

But what brought this post up was that ridiculously precise figure on how much CO2 your kids are going to produce. It’s utterly ridiculous to speculate on things that will not happen for many decades. If nuclear fusion becomes viable by 2050, the carbon footprint of my kids and grandkids will be far lower than mine. It’s the return of he Fallacy of the Unbroken Trend. Since carbon emissions per capita have followed trend X, we can extrapolate trend X a century into the future and draw conclusions appropriately.

Garbage.