Population has not been raised as a major issue in climate talks, but it should be. China is the only country that has mentioned it at all.

The developed countries are dodging the idea of stabilising population because their economies are based on continuous growth, and population growth is an easy way to do that: More people = more consumers.

However, more people also means more of everything that is damaging the planet, especially more people living rich country lifestyles. Developed countries could stabilise their populations tomorrow if they so chose, because most have birth rates lower than death rates. It is immigration that is keeping population growth going in the rich countries, and at the risk of being labelled a racist, I will say that immigration must be immediately reduced to result in a stable population in the developed countries.

This does not mean no immigration, but only enough to maintain the current population. Refugees and family members should still be permitted up to that level, while visas for skilled workers and rich people should be ended.

My country, Canada, currently has a population of approximately 36 million. In theory, Canada is a vast country, but much of it is inhabited only at a very high cost in energy. Ninety percent of the population lives within 200 kilometres of the southern border for a very good reason: Canada is cold much of the year, and northern Canada is extremely cold. Canada’s northern cities are dependent upon the more southerly areas for food; you really can’t grow much in Churchill, Manitoba, where the average temperature in July is only 12C (54F).

Climate change adds great uncertainty to the number of people Canada will be able to support in the coming years. The vast prairies are currently a giant breadbasket, producing huge quantities of wheat. However, climate change is expected to dry large swaths of the prairies; another dustbowl, this time permanent, is quite possible.

Beyond simplistic calculations of how many humans a nation like Canada theoretically support, we must consider if it makes sense to pack a country full. Brazil could support millions more – but the rainforest would have to cleared for farmland and cities. That is hardly sensible. I suggest that the prairies of Canada are as valuable as the rainforest in their own way. They may have to be reverted to prairie to both prevent a recurrence of the catastrophic dust bowl caused by tilling the soil using industrial farming techniques, and to sequester carbon from the atmosphere in the form of plant and animal life.

The principle is this: the more of nature we leave wild, the more stable will be the Earth’s climate.

There is a further consideration, and this is where the accusations of racism typically begin to fly. Canadians should ask themselves not just how many people can Canada hold, but how many do we want ? I do have a personal stake in this, as my wife is Colombian.

Consider this: the Greater Toronto Area currently has a population of 5.5 million. The many cities surrounding the GTA – Hamilton, London, Guelph – the whole Golden Horseshoe – have also been growing very rapidly. All of these cities are built on the best farmland in Canada. That is just not smart. How many people do we want to put in this area? Until the entire Golden Horseshoe is paved and populated? How many is enough? Should Toronto be a city of 10M? 25M? 50M?

And what should Canada’s population be? The governing Liberal Party of Canada floated the idea of 100 million people – based on what? Canada is larger than China, perhaps the population should be larger, too? Maybe Canada should aim for 1.5 BILLION people? This is insane. An entire generation has been priced out of housing – they will never be able to buy a home. More people will only make that worse.

In reality, all countries should be aiming for zero or even negative population growth – degrowth. Climate change is already making it harder to feed and house everyone. A bigger population used to be an advantage economically and militarily. No more – now too many mouths to feed is a disadvantage.

Sooner or later, population growth must stop. I am saying that time is now. We can choose our path, or climate change will force it upon us.