Most Americans cringe at the thought of government enacting population control measures and plans to curb fertility rates. The notion of injecting partisan bureaucrats into the deeply personal decision to have children is patently contrary to the ideas of American independence and liberty. But that’s not stopping a growing movement within the environmental left that is now adopting these radical plans in the name of fighting global warming.

Although population control remains safely in the fringe of the political sphere, advocates of this beta-anti-humanism are starting to feel safer coming out of the closet with their true beliefs, a remarkably disturbing development.

Earlier in January, HGTV stars Chip and Joanna Gaines announced they were expecting their fifth child. Along with the expected messages of celebration and support, the couple also faced backlash over this joyous news. For instance, critics on Twitter wrote, “I like them ok but enough with the kids already,” and, “Thank you for contributing to the over population of the planet.” A Facebook user added to the outrage by writing, “Overpopulation is killing the planet. Having another child is an irresponsible act.”

Instead of rejecting these unconventional responses, some on the left have embraced them. In an especially egregious opinion article, Canadian Broadcasting Company contributor Kristen Pyszczyk made the case for increasing the condemnation of people who have children.

“Procreation is becoming a global public health concern, rather than a personal decision. So when people do irresponsible things like having five children, we absolutely need to be calling them out,” Pyszczyk wrote.

“Shame is a powerful tool for changing behaviour,” and “we need to go much further,” she added.

Some might feel inclined to write Pyszczyk’s article off as a bizarre one-off opinion produced by a solitary kook writer, but the truth is her opinion is shared by a large group of environmentalists who have made their voices heard in prominent publications such as The Guardian, NPR, The Nation, Vice, The Huffington Post, Elle Magazine, NBC, and many more. Article titles include, “Want to fight climate change? Have fewer children,” and “How Do You Decide to Have a Baby When Climate Change Is Remaking Life on Earth?”

It’s true not all these examples support extreme population control efforts, but the wealth of articles on this topic shows the conversation is becoming much more mainstream.

A recent piece that grabbed a lot of attention was featured on NBC News’ “Think” page. The article, titled “Science proves kids are bad for Earth. Morality suggests we stop having them,” makes the case that because “having a child is one of the worst things you can do for the environment,” parents should consider the moral implications before procreating.

The author of the article—Travis N. Rieder, assistant director for education initiatives at the Berman Institute of Bioethics—also co-authored a disturbing report for the October 2016 issue of Social Theory and Practice titled “Population Engineering and the Fight against Climate Change.” In this report, Rieder et al. outlines several policies designed to lower fertility rates in developed countries. These policies are organized by levels of coercion, starting with increasing women’s access to abortions and ending with tailoring the tax system to discourage reproduction. Thankfully, Rieder stops just short of recommending the type of direct coercion imposed in China through the country’s notorious single-child policy.

Behind all these radical proposals is a firm belief in man-caused catastrophic global warming. If you really want to save the world from total disaster, they argue, you need to refrain from creating new carbon-dioxide-emitting beings (humans) to lower your carbon footprint.

Along with being grotesque to the vast majority of people around the world, these stances are often illogical and contradictory. In Pyszczyk’s CBC piece, for example, she suggests a woman’s itch to become mother can be scratched by adopting kids from struggling countries from around the world. Adoption is a noble, selfless act that I would never discourage, but it flies in the face of the justification these extreme environmentalists use to justify their anti-human stances. If limiting our carbon footprint is the goal, then adopting kids is not the answer. Babies from the developing world don’t bring their relatively small carbon footprint with them; they will almost certainly end up with a carbon footprint comparable to most people born in their new country.

Similarly, having the stance of limiting birth rates while simultaneously being pro-immigration and pro-open borders is completely contradictory. If you care so much about limiting carbon-dioxide emissions that you want to keep people from having kids — or, at the very least, discourage it — then you should oppose any effort to bring people into the United States, one of the world’s highest per-capita carbon-dioxide emitters.

Many environmentalists will contend the alleged carbon-dioxide problem is limited to the developed world. As Rieder states in his report, “While reducing fertility in developing nations is important, since their per capita [greenhouse gas] emissions are projected to increase significantly (and should be allowed to do so) over the next several decades, it is not nearly as critical as near-term reductions in the numbers of the world’s wealthy.”

But this claim ignores the fact that fertility rates are negatively correlated with a country’s prosperity. Generally, the wealthier a country is, the lower the fertility rates are. At the end of the day, logic appears to have no place at the table for those with an alarmist environmental agenda.

The push for population control and reduced birth rates is still relegated to the fringe of the environmental movement, but we shouldn’t assume it will stay that way. We must be vigilant and push back against this festering worldview whenever it rears its ugly head, always remembering that other similar movements have caused great harm in world history. At this rate, it might not be long until we have to deal with such a crisis again.

Until then, be fruitful and multiply—while you still can.

Donald Kendal (dkendal@heartland.org) is co-host of Heartland’s In The Tank podcast – a show that explores policies, politics, and the work of think tanks across the country.