When people ask her if she has children, Münter, who is 44, has a prepared answer: “No, my husband and I are child-free by choice.” Saying child-free, she argues, doesn’t imply you are deprived, as the more standard “childless” might. And by letting them know it isn’t a sad topic to be avoided, she says, “it opens up the door for them to ask: ‘Oh, that’s interesting, why did you choose not to?’” Münter wants to move the awkward topic of overpopulation into the mainstream. “The more we talk about it, the more comfortable people will feel talking about it and then, maybe, things will change.”

For too long, she feels, the issue has been swept under the rug. “We can talk about emissions and climate change, but talking about population gets such an emotional reaction.”

The last thing she wants to do is make parents feel guilty, or to shut them out of the conversation. Procreation, after all, is natural. And if you have two children, you are only replacing their parents, rather than adding extras. But if you’re not yet a parent and can’t suppress your parental instincts, says Münter, “my ask is that you consider adopting one of the 153m orphan children that are already on the planet and need a home. Or, if you are dead set on having your own, my hope would be that you just have one and then if you want more, adopt.” Ultimately, she says, “your kids and your kid’s kids will be the ones who benefit from humans deciding to slow down our rate of growth. It will slow down climate change, ocean acidification, cutting down the wild places.”