Canada's greenhouse gas emissions do matter to the world

A paper in Nature that has attracted some attention this week reminds me that I've been meaning to write about why it is important for Canada to reduce its greenhouse gas emissions, even though they represent only a few percent of the total world emissions. You sometimes hear critics of devoting resources to fight climate change say that reducing our emissions is not going to make any difference. However, "doing our part" to reduce emissions isn't like voting, obeying the speed limit, or playing a team sport. These examples are missing a crucial dynamic, that of competition and of a limited, public resource.

The problem of climate change caused by human emissions of greenhouse gases is an example of a tragedy of the commons. The image this term is meant to evoke is that of pastoral villagers, each with cows that graze on a shared grassy commons. What one villager's cows eat is lost to the others so every villager is tempted to use up the commons as quickly as possible. As for climate change, we all pay when someone uses the atmosphere (the commons) as a 'free' dumping ground. When a single person pays to reduce emissions, everybody else benefits. Sensible individuals might conclude that the best thing to do is to take advantage of the free dumping ground (burn fossil fuels) as much as possible. But if everybody were to think that way, everybody would lose in the end.

The way out of such a tragedy is cooperation. In the case of greenhouse gases, this might take the form of an agreement between all parties to limit emissions, or to pay for emissions. It is very important in this dynamic that everybody is seen by others to be cooperating. Nobody should be seen as 'getting ahead' by cheating because then everybody else would be encouraged to do the same and cooperation would break down.

This point is the key to why Canada must reduce its greenhouse gas emissions. Canada has one of the highest per capita emissions of greenhouse gases in the world. Cooperation can't happen when a few people are taking advantage of the commons a lot more than others. Cooperation is fostered by people providing moral leadership. In this respect the small, the weak, or the small-in-number have always, historically, had opportunities to lead.