Common law is judge-made law developed through the court system. Originally, the common law did not include written texts, it was simply made up of court decisions. Today, however, more of the common law has been written down, whether in court decisions or confirmed in legislation.
Two main ideas run through the common law: (1) Judges do not make the law but merely declare it, and (2) All relevant past decisions are considered as evidence of the law and judges infer from these past decisions (precedents) what is the true law in a given instance.
This reliance on past cases is an important legal concept called stare decisis which means “let the decision stand”. This helps judges decide how to interpret a set of facts based on what has been decided before them.
As with other types of law, environmental lawyers have relied heavily on common law ideas in order to protect certain aspects of the environment, especially before environmental statutes existed. A number of examples come from an area of law known as torts. A tort, as defined by Black’s Law Dictionary, is, “a civil wrong for which a remedy may be obtained, usually in the form of damages; a breach of a duty that the law imposes on everyone in the same relation to one another as those involved in a given transaction.”
In simpler terms, torts govern the relationship between individuals even when there is no contractual relationship. Here are some examples of torts to better understand how they can play a role in environmental law and the protection of the environment:
One Canadian example of a toxic tort is the decision of Smith v Inco Ltd. out of Ontario. In this case, a group of landowners sued a nickel refinery after their property values decreased as a result of nickel particles being deposited onto their property. This decision was important as it could result in more Canadian toxic tort litigation in the future.
 Neil Craik et al, Public Law, 2d ed (Toronto: Edmond Montgomery, 2011) at 52.
 Black’s Law Dictionary, 7d ed, sub verbo “tort”.
 Bruce Pardy, Environmental Law: A Guide to Concepts (Toronto: Butterworths Canada Ltd. 1996) at 193.
 Smith v Inco, 2010 ONSC 3790.