If you live in Vancouver, you might come across some controversial signs advertising for small or child-free families. 

The signs, which have started to pop up in multiple areas across the city, are part of a campaign called One Planet, One Child by U.S. group World Population Balance, to encourage single-child families or families with no children. 

Controversial billboards and transit ads are up around #Vancouver, encouraging child-free and single-child families. Find out more about the group behind the ads and how people are reacting on @CityNewsVAN at 6. @NEWS1130 @BT_Vancouver pic.twitter.com/BCRihXRXix

— Miranda Fatur (@MirandaFatur) September 24, 2020

The group's website says that the ad campaign is raising awareness for overpopulation to speed progress toward a "small family norm."

They even went on to explain why they chose to put their ads up in Vancouver in particular. 

"Human overpopulation is present in Vancouver just as it is in most parts of the world. Everyone around the world needs to be aware of this crisis, because we all have a role to play in resolving it," the website states. 

New billboard campaign in Vancouver targets global overpopulation https://t.co/XAMlYZO5Cm
Expose the financier behind the ads! Money will be better spend helping third World Country's sexual education programs! Not Canada, many couples are already choosing not to have children!

— Chan (Danny) Tse (@ChanDannyTse2) September 25, 2020

In an interview with Freshdaily, executive director Dave Gardner added that they are running the ads to start a conversation about overpopulation. 

"People have avoided the subject of overpopulation for so long and there really isn't widespread knowledge that we have a human overpopulation crisis," he said.

"We're confident that if people know the facts they'll be a lot more comfortable talking about it and addressing it. We really can solve that part of the sustainability problem that doesn't have to take hundreds of years and the solution is ethical."

Of course, the ads have sparked quite a bit of controversy and many have taken to Twitter to voice their concerns. 

Disgusting ad

— klaus kimchi (@maximum_sincere) September 25, 2020

"I chose not to have kids, but this advertising campaign is bordering on a human rights issue, no? Seems kind of messed up," someone else wrote.

@TransLink this is NOT ok

This ad should be taken down immediately !

— Christine (@cristinenmarie) September 25, 2020

"As a single child, I can tell you that is the worst gift you can give a child. Have none or have 2. 1 is no fun," another Twitter user added.

This is ridiculous and insulting for so many reasons. But its also unnecessary as Canada already has a fertility rate of 1.5, which is significant population decline on its own.

— Shannon ❤️ Pixels (@shanathalas) September 25, 2020

The criticism was not unexpected, Gardner said.

"In some respects, that's valuable because it really does get people talking about it and if we can have a conversation, hopefully, we can allay any misconceptions."

World Population Balance also has ads in cities across the United States.