State sovereignty, the United Nations and international environmental instruments: HSC Legal Studies

What this dot point is asking

The second part of the option, responses to global environmental protection, lists the roles of eight actors. This page covers the first three: the nation state and state sovereignty, the United Nations and international instruments. The syllabus asks you to examine the role of sovereignty in assisting and impeding the resolution of global environmental protection issues and to outline the structure and function of the United Nations in relation to environmental protection. The remaining roles (courts and conferences, intergovernmental organisations, non-government organisations and the media) are on the courts, conferences, IGOs, NGOs and media page, and Australia's federal structure has its own page.

State sovereignty is the first theme of the option and the thread through almost every exam question. NESA's 2023 feedback said better responses explained state sovereignty as a barrier and supported the point with evidence, and its 2025 feedback on non-compliance rewarded responses that showed how the law develops through instruments such as the Paris Agreement.

The answer

The nation state and state sovereignty

A nation state is a political community with a defined territory, a permanent population, a government and the capacity to enter into relations with other states. State sovereignty is its supreme authority over its territory and people, free from outside interference. The UN Charter is built on it: the UN is based on "the sovereign equality of all its Members" (art 2(1)) and may not intervene in matters "essentially within the domestic jurisdiction of any state" (art 2(7)).

In environmental law, sovereignty has a specific form. UN General Assembly resolution 1803 (1962) affirmed permanent sovereignty over natural resources: forests, minerals, fossil fuels and water within a state's territory are its to use. Stockholm Principle 21 (1972) and Rio Principle 2 (1992) pair that right with a responsibility not to damage the environment of other states or areas beyond national jurisdiction. The tension between the right and the responsibility runs through every issue in this option.

How sovereignty assists environmental protection.

• Only states make international law. Treaties exist because sovereign states negotiate and ratify them. The Montreal Protocol (1987) is the best example of sovereign states agreeing to a strong, binding regime: it is ratified by every UN member state and has phased out nearly all ozone-depleting substances.
• Only states enforce it at home. International obligations become effective through domestic law. Australia's World Heritage Properties Conservation Act 1983 (Cth), upheld in Commonwealth v Tasmania (1983), and the EPBC Act 1999 (Cth) implement treaty obligations.
• States can lead and litigate. Australia used its standing as a sovereign state to bring Whaling in the Antarctic (Australia v Japan; New Zealand intervening) to the ICJ, which ruled in March 2014 that Japan's JARPA II program was not "for purposes of scientific research". Vanuatu, a state of about 300,000 people, built the coalition that led the General Assembly to request the ICJ's climate advisory opinion (resolution 77/276, 29 March 2023).
• Sovereign coalitions. Groups of states, such as the Alliance of Small Island States or the High Ambition Coalition, use their votes to push negotiations forward. At COP30 in 2025, more than 80 countries backed a roadmap for transitioning away from fossil fuels.

How sovereignty impedes environmental protection.

• Consent. Under the Vienna Convention on the Law of Treaties, a treaty binds its parties (art 26) but creates no obligations for a state without its consent (art 34). The United States never ratified Kyoto and is not a party to the Convention on Biological Diversity.
• Withdrawal. States can leave. Canada withdrew from Kyoto with effect from December 2012; Japan left the International Whaling Commission in 2019 and resumed commercial whaling in its own waters; the United States notified its withdrawal from the Paris Agreement on 27 January 2025, which took effect on 27 January 2026, and on 27 February 2026 notified its withdrawal from the UNFCCC itself, effective 27 February 2027. It will be the first state to leave the UNFCCC.
• Self-set targets. Paris respects sovereignty by letting each state set its own NDC. The UNEP Emissions Gap Report 2025 found that even full implementation of current NDCs leads to 2.3 to 2.5°C of warming.
• Weak compliance. The Paris compliance committee is "facilitative" and "non-punitive" (art 15). No international body can fine a state for missing its target.
• Consensus decision-making. Most environmental negotiations proceed by consensus, so a few states can block agreement. Talks on a treaty to end plastic pollution ended without agreement in Geneva in August 2025. At the International Maritime Organization in October 2025, a vote to adjourn adoption of a net-zero framework for shipping for one year passed amid open opposition from the United States.
• Economic interest. States approve projects that serve national economic interests even where the emissions affect everyone, such as Australia's approval in September 2025 of the North West Shelf gas project extension to 2070 (see conflict over resources).
• Jurisdiction. The ICJ can only hear contentious cases with the consent of the states involved.

The United Nations: structure and function

The United Nations has no single environmental organ. Its environmental work is spread across principal organs, programmes, treaty bodies and specialised agencies.

Evaluating the UN's role. The UN is most effective at promoting: it sets the agenda, produces the science (IPCC, UNEP), provides a forum where every state has a voice, and develops law through conferences and treaties. It is less effective at achieving protection, because it can only coordinate sovereign states. Its outcomes depend on the political will of its members, and the most powerful body, the Security Council, has not been able to act on climate.

International instruments

International instruments are the treaties and declarations through which states make environmental law. Distinguish soft law (declarations and resolutions, not binding) from hard law (treaties, binding on parties).

Why the Montreal Protocol worked and Kyoto struggled. The comparison is a favourite for "effectiveness" questions. The Montreal Protocol dealt with a narrow set of chemicals for which substitutes existed, it had clear science (the ozone hole discovered in 1985), trade measures against non-parties, and a Multilateral Fund that paid developing countries' compliance costs. Kyoto tried to regulate the energy base of the whole economy, bound only developed countries, and lost major emitters (the United States never ratified; Canada withdrew). Paris traded stringency for participation.

Evaluating these responses

Judgement. Sovereignty, the UN and international instruments have promoted environmental protection very effectively: almost every state now accepts that it has environmental obligations, and the ICJ confirmed in 2025 that those obligations are legal, not just political. They have achieved protection only where states' interests align, as with ozone. On climate and biodiversity, sovereignty remains the decisive limit, shown most clearly in 2026 by the United States leaving the Paris Agreement and preparing to leave the UNFCCC.

In one sentence

State sovereignty is both the source of global environmental law, because only states make and enforce treaties, and its main limit, because states set their own targets and can walk away, so the UN and international instruments such as the Montreal Protocol and the Paris Agreement promote protection effectively but achieve it only where sovereign interests align.

Try this

Q1. Identify TWO ways state sovereignty impedes global environmental protection. (2 marks)

• What the marker wants. For example, withdrawal from treaties (United States from Paris, 2026) and self-set targets under Paris.

Q2. Outline the role of UNEP. (4 marks)

• What the marker wants. Created 1972; coordinates UN environmental work; assessments (Emissions Gap Report); hosts secretariats; the UN Environment Assembly and plastics treaty talks.

Q3. Evaluate the effectiveness of international instruments in protecting the global environment. (8 marks)

• What the marker wants. Hard and soft law distinguished; Montreal (effective) versus Kyoto and Paris (limited), with evidence; the role of sovereignty; a judgement.