One way to understand the theory of the Tragedy of the Commons is to think about the ocean.
The ocean covers more than 70% of the Earth’s surface.  It touches all of the continents and dozens of countries, which means that it is not, and cannot, be entirely controlled by anyone. On the other hand, everyone (or almost everyone) makes use of it in some way – whether that is by eating fish, travelling by boat, purchasing items that have traveled by boat, or recreational activities such as swimming, snorkeling, or scuba diving. It also means that, to most people, the ocean seems like an endless resource.
However, no matter how big the ocean is, there is a limit to how much we can pollute and exploit our ocean resources.
Now, that you are thinking about the ocean, start to imagine that you are a company producing a lot of liquid garbage, let’s call you Company ABC. (Let’s also imagine that this is occurring at a time before the Canadian government began to regulate what you can put in the ocean.)
At the end of every day, you, as Company ABC, need to do something with your liquid garbage. You cannot dump it on the ground beside your building because somebody lives there (they bought that piece of land so it is now considered to be private property). There are treatment processes available that allow you to clean the waste and then dump it out as clean water but that would cost a lot of money.
You decide to dump it into the ocean. And since the ocean is so big, it quickly disappears under the waves and you cannot even see the waste after a few minutes. When you first start doing this, you are the only big company making liquid waste anywhere in the world so it doesn’t seem to make much of a difference. As you know, the ocean is huge and you only dump a little bit of waste into the water every day. But then another company opens up next door and then another one and another one.
Soon there are numerous companies creating liquid waste every day. They are faced with the same dilemma as you were when you first started. Unsurprisingly, and for the same reasons, they start dumping their liquid waste into the water as well.
Quickly, the number of companies grows and soon there are dozens, then hundreds, and then thousands of companies dumping their liquid waste into the ocean every day.
Although each company individually benefits from saving money through this method of dumping, everyone, including all those people who do not even work at one of these companies, is impacted by the environmental problems that accompany a polluted ocean. The ocean, or the commons, is now being polluted by litres and litres of waste, every single day. What began as a small problem grew very quickly because everyone had access to the ocean and nobody was responsible for its cleanup.
Garret Hardin would have referred to this problem as the ‘Tragedy of the Commons’.
Next, let’s imagine a smaller scale example. Imagine now that you are a cattle farmer. One day, you find a pasture, empty and covered in your cattle’s favourite grass. This field is considered to be ‘common property’ and where you live that means that anyone can bring their cattle here to graze. So you do. You get to make the final decision about how and when to graze your animals, in isolation of other farmers.
But then your next door neighbour hears about the pasture and brings her cattle here to graze and then her next door neighbour does the same and so on and so forth. Each farmer chooses to do the same because each of them individually benefits from their cows being well fed.
Eventually, because there are so many cattle grazing, the grass is overeaten, trampled by the cattle and each summer there is less and less grass that grows back. One day the grass is finally gone. Everyone used the field for their own benefit but nobody took responsibility for it and eventually, this led to the degradation of the resource – the grass. 
The Tragedy of the Commons in 21st Century Alberta
In today’s society, with our highly regulated land-use systems what was described by Hardin as common or public property does not necessarily even exist. Even that which is described as public land in Alberta is actually governed by the Alberta government under the Public Lands Act, which you can find here. This Act places restrictions on the use of public lands in Alberta.
For example, the Public Lands Act prohibits certain activities on public land (without permission) and it permits the leasing of portions of public land to farmers to allow their cattle to graze on, along with other permitted and prohibited uses.
This means that, although approximately 60% of Alberta is made up of ‘public’ lands, it is not actually a “free for all” in the way that Hardin described it. This restriction of provincial public land, through governmental regulation, is one way that we have tried to prevent the Tragedy of the Commons.
Despite this, the theory of the tragedy of the commons is an important concept to begin wrestling with. It becomes increasingly important when you begin to consider how best to deal with large scale environmental issues – issues which are often global and have far-reaching effects.
At this point in time, we cannot stop using resources all together. Human life as we know it would end if we did not have access to the vast resources our planet has to offer, so instead the question has to be, how much of any single resource can we use before it is too much?
The differences in how we deal with the Tragedy of the Commons, in both theory and practice, have really just been an attempt to answer the question: who determines what is too much and how do we measure how much is too much?
One option is for governments to tell us what “too much” means and they can do so through government regulation, such as putting limits on emissions, managing water use, and controlling access to fish and wildlife.
The second option is that the economy, through privatization, defines what “too much” means. This can be done by allowing the market to determine value or by enabling private owners to access the court system if others interfere with privately owned resources.
The third option is for community members to control and protect their own resources whether through cooperatives or other organizing activities. This is a less common option in Alberta but may be a better way to prevent many of the downfalls inherent to both government regulation and private property.
 NOAA, “How much water is in the ocean?” online: National Ocean Service https://oceanservice.noaa.gov/facts/oceanwater.html.
 Garret Hardin, “The Tragedy of the Commons” (1968) 162:3859 Science at 1244.
 Amy Sinden, “The Tragedy of the Commons and the Myth of Private Property Solution” (2007) 78:2 U Colo LR 533.
Join our new Alberta Environmental Laws 101 Facebook group to ask questions, participate in discussions and keep up to date on environmental news. Please share this widely so that the high school teachers and students in your circles hear about this great new resource for supplemental online learning. Alberta Environmental Laws 101 Facebook Group