Canada's "natural" population growth (births vs. deaths) is pretty close to zero.  Most other developed countries are the same with several (Germany, Japan), having negative "natural" population growth.

Population growth in developed countries is predominantly caused by immigration from less developed countries.  Virtually all global population growth is happening in just 3 places: South America, Africa and some of the less developed parts of Asia.

Now, you can argue the right or wrong of this, but you should keep in mind that the argument you are trying to make is, as a resident of a wealthy country, that you want people from less wealthy countries to have fewer babies.  That message might not be well received.