In recent decades, international law has also become more relevant to the environment. Most nations (including Australia) have entered into various treaties, conventions and protocols (agreements) - usually under the auspices of the United Nations.

Many of these international agreements are worded so as to be legally binding on nations which sign them. However treaties are not legally binding within a country unless they have been enacted into domestic law. Examples of treaties that have been enacted in Australia include the World Heritage Convention and the Montreal Protocol on Ozone-Depleting Substances.

Most environmental treaties have not yet been enacted into Australian law and are not therefore enforceable by Australian citizens. Nevertheless, the main value of such treaties is that they are highly morally persuasive and they are often implemented at a policy (rather than legal) level.

South Australia has passed [see Administrative Decisions (Effect of International Instruments) Act 1995 (SA)] (and the Commonwealth has proposed) controversial legislation which limits the status of international treaties to that of non-binding policy documents only.