It’s surprising in many ways that population size domestically and globally doesn’t get more press and discussion in mainstream media.
But maybe, it’s not surprising, it’s a touchy subject with people. No one wants to tell people how many kids they can have or should have, and it’s not a conversation a politician is likely to enter into.
Population size is one of the major factors affecting our impact on the planet, along with how much each of us consumes in terms of resources and the technologies we use. It’s also the biggest factors that is going to dictate our future quality of life on this planet. So maybe we should be talking about it more before it’s too late.
Population size has quadrupled in the last 100 years. It took until the early 1800’s for world population to reach a billion people and until 1960 to reach 3 billion. We are now at 7 billion people. You can see how fast total population numbers are increasing.
Meeting the needs of an ever increasing population size is placing a huge burden on the planet’s ecosystems. And yet, we are already exceeding the earth’s bioproductive capacity.
Worse yet, significant increases in total world population over the next several decades are almost inevitable the experts say, in spite of a decline in the overall population growth rate. This is due to something they call the “population momentum”
Basically, this means that because nearly one third of the world’s population is under 15 years of age and yet to reach child bearing age, when they do reach child bearing age, even if each woman has fewer children than in the past. This will still result in a significant increase in world population.
So where’s all this population increase occurring? Well most of it is in developing countries, where growth rates are higher than for developed countries. The one exception is the United Stats with one of the fastest growing populations.
When growth rates are higher it’s usually because poverty is associated with higher birth rates because having more kids means greater security for those having them when you’re living so close to the edge
Ignoring the high birth rate exception of The United States for a minute, economic growth is sometimes offered as the answer to poverty which would in turn reduce the birth rate.
The problem with this argument the experts say, is that economic growth over the past several hundred years did not reduce poverty and there is little reason to expect it to work in the future.
Instead they say almost the opposite thing is what works i.e. enable people to have fewer kids if they want, that then stimulates development which in turn reduces poverty individually and at the macro economic level. So to recap what they say:
This doesn’t work
Increase economic growth (GDP) 
leads to decreased poverty leads to decreased birth rate 
But this works
Help people have fewer kids if they want leads to reduce birth rate
leads to increased economic growth leads to decrease poverty
It’s probably a good thing we don’t have to increase economic growth first in order to reduce the birth rate because we are already exceeding the earth’s bioproductive capacity.
In other words, we are using the world up faster than it can replenish itself. Not only that, but if everyone on the planet needs to increase economic development and consume at the level of North America, then we would need approximately 3-4 planets like earth to supply us.
So something has to give. We’re either going to have to figure out how to make the earth’s resources go further i.e. produce the same toaster or car with 1/4 of the materials or we are going to have to reduce consumption (no car, no toaster) or we are going to have to reduce population.
This is why the international community generally agrees on the need for population control measures because in order to bring things back to a sustainable level you have to control population. The smaller the population, the easier it will be for all of humanity to have a decent level of well being.
We could also reduce consumption levels by everyone on the planet to help solve the problem, but economic growth is such a dominant policy paradigm at all levels of government, especially in Canada and the USA, that this doesn’t seem likely to change in the near future. This is another issue no one wants to discuss. The only thing that is clear is that we are on an unsustainable path for a variety of reasons. What will happen? Who knows?