2. Public International Law
2.1. Sources of International Law
Public international law is the body of law that addresses the interactions between states and other relevant actors.[1] It is a relatively primitive legal system compared with most domestic legal orders. In formal terms, the law is made by states, the primary actors in the international legal system. A convenient summary of the content of international law is found in Article 38 of Statute of the International Court of Justice (‘ICJ Statute’), which directs the Court to apply the following sources when addressing cases brought before it: (a) treaties, (b) customary international law, (c) general principles of law, and (d) judicial decisions and academic writings.
Treaties are binding agreements entered into between two or more states, and there are now thousands of treaties on a range of topics, including climate change. Customary international law refers to legal rules that develop out of the practice of states where states regard that practice as being required as a matter of law. This means that constant and uniform practice over a period of time can give rise to new rules of law. There are a number of customary rules, such as the prohibition on transboundary harm, of relevance to climate change.[2] A third source of law is general principles of law. These primarily concern norms that are shared across legal systems that relate to matters such as due process, and they are of limited relevance to climate issues.
The final sources of international law referred to in the ICJ Statute are the decisions of national or international courts and the writings of distinguished scholars. While there is no system of binding precedent in international law, judicial decisions have been influential in the development of the law, including in relation to environmental issues.[3] For instance the International Court of Justice (‘ICJ’) is currently considering the obligations of states in relation to climate change in Advisory Proceedings.[4] This is a specific type of jurisdiction that empowers the Court to respond to legal questions put to it by organs and agencies of the United Nations.
2.2. Incorporation into Australian Law
International law imposes obligations on states on the international plane, but in performing those duties it will often be necessary for states to pass new laws or amend existing laws within their own domestic legal systems. International climate law is no exception, and a domestic legal response is needed, even if states have some flexibility in choosing what form their domestic law will take.[5]
In Australia there are a number of Acts and Regulations at a national and state/territory level that give effect to Australia’s obligations under the UNFCCC and subsequent treaties. These include the Climate Change Act 2022 (Cth), which sets out Australia’s greenhouse gas (GHG) emissions reduction targets, provides that the Commonwealth government must make annual climate change statements, and confers advisory functions on the Climate Change Authority. In addition to the body of Commonwealth law, there is also legislation in a number of the states and territories that address climate change.[6]
There are also potential opportunities for using international climate law in domestic climate litigation in many jurisdictions,[7] although the extent to which these are left open in Australia is determined by relevant legislation. For instance, litigants in proceedings in Australia challenging approval of a new coalmine cannot simply rely on the Paris Agreement, or any other international law as directly enforceable law, and must mount their case on the basis of the relevant statutory framework which may, or may not, allow the courts to consider international law. Notably, Australia’s national environmental law, the Environment Protection and Biodiversity Conservation Act 1999 (Cth) (‘EPBC Act’), does not require detailed consideration of the climate impacts of fossil fuel projects. As Peel observes, the EPBC Act ‘is not fit-for-purpose as a measure for evaluating how domestic fossil fuel projects contribute to global GHG emissions levels and climate change’.[8]
- See generally Ben Saul, ‘Overview of Public International Law’ in Emily Crawford, Alison Pert and Ben Saul (eds), Public International Law (Cambridge University Press, 2023) 1. ↵
- See Christina Voigt, ‘Climate Change and Damages’ in Kevin R Gray, Richard Tarasofsky and Cinnamon Piñon Carlarne (eds), The Oxford Handbook of International Climate Change Law (Oxford University Press, 2016) 464. ↵
- See further Tim Stephens, International Courts and Environmental Protection (Cambridge University Press, 2009). ↵
- Obligations of States in Respect of Climate Change <https://www.icj-cij.org/case/187>. ↵
- See generally Jacqueline Peel and Tim Stephens, ‘Australia and International Environmental Law’ in Donald R Rothwell and Emily Crawford (eds), International Law in Australia (Thomson Reuters, 3rd ed, 2017) 457. ↵
- See, eg, the Climate Change (Net Zero Future) Act 2023 (NSW), which legislates the emissions reduction targets adopted in NSW with multi-party support and establishes an independent Net Zero Commission to monitor, review, report on and advise on progress towards these targets. ↵
- See further Jolene Lin and Jacqueline Peel, Litigating Climate Change in the Global South (Cambridge University Press, 2024). ↵
- Jacqueline Peel, ‘The Living Wonders Case: A Backwards Step in Australian Climate Litigation on Coal Mines’ (2024) 36(1) Journal of Environmental Law 125. ↵
Adverse effects experienced in one State caused by or originating from an area under the jurisdiction of another State.
Jurisdiction refers to the scope of a court’s authority to decide matters. It comes from the Latin ‘juris’ (the law) and ‘dicto’ (to say or declare).
Cases where climate change is a central issue in the dispute, climate change is raised as a peripheral issue, climate change is one motivation behind the case, or where the case has implications for mitigation or adaptation (Jacqueline Peel and Hari Osofsky, Climate Change Litigation: Regulatory Pathways to Cleaner Energy, Cambridge University Press, 2015, p. 8).
An energy source formed in the Earth’s crust from decayed organic material. The common fossil fuels are petroleum, coal, and natural gas.[1]
[1] U.S. Energy Information Administration (EIA), Glossary <https://www.eia.gov/tools/glossary/index.php?id=Fossil%20fuel#:~:text=Fossil%20fuel%3A%20An%20energy%20source,%2C%20coal%2C%20and%20natural%20gas>.
