International Environmental Law

Author: Abbas Poorhashemi

Required knowledge: Public International Law

Learning objectives: This chapter book aims to discuss and present the essential elements the foundation and emergence of international environmental law as a new branch of international public law. Furthermore, it tries to provide some knowledge on the sources and principles of international environmental law.  Environmental challenges such as climate change, desertification, air pollution, sea pollution are amongst the most urgent that require an immediate and collective response from the international community. Understanding the opportunities and challenges facing the international community is crucial for the future development of international environmental law.

A. Emergence of International Environmental LawEdit

International Environmental Law as a new branch of public international law emerged in the 1970 decades. Hence, environmental protection has become a significant concern and preoccupation of the international community. Climate change, air pollution, lack of safe drinking water, wastes and hazardous, soil erosion, loss of biodiversity and noise and light are the global challenges of humanity. To respond to these environmental challenges and problems, the international community has recognized that environmental protection must be addressed holistically and expansively. Moreover, the international community has become aware that the local issues cannot be separated from national, regional, or even global conditions.[1] Although there are various definitions of "International environmental law," the definition given by Alexander Kiss and Dina Shelton[2] is significant. In their view, international environmental law is the newest branch of public international law, which aims to protect the environment. Some also define international environmental law as "a set of rules of international law which the purpose is to prevent environmental pollution and to protect the environment." While the above definitions are positive, they are not exhaustive.[3]

B. Generations of International Environmental LawEdit

International environmental law is developing as one of the branches of public international law. Although the conservation of some species of animals and plants dates back to the pre-1970s, the basis for the formation of international environmental law, in its modern concept, is the Stockholm Declaration of the United Nations Conference on the Human Environment in 1972.[4] In general, international environmental law is historically divided into three periods:

First generation: before the formation of international environmental law until the 1972 Stockholm ConferenceEdit

The first generation began mainly in the 18th century with the signing of especially bilateral agreements in the field of fisheries and marine life resources. Its expansion to other fields, including wildlife, rare and endangered plants and animals species, continued into the early twentieth century. The most important feature of this historical period is its regionality and the creation of contractual obligations between states to protect a particular region or species. The 1960s, generally known as the decade of student movements (the women's movement, the green movement, and the postmodern movement), marked a turning point in the destructive process of modernity and addressed many fundamental issues, including environmental matters. Subsequently, environmental activists and scientists declared that if industrial progress continued the same way, the world would be destroyed. As a result, by the end of the decade and the beginning of the 1970s, the states were forced to hold the Stockholm Conference of 1972.[1] The Stockholm Conference of 1972 recognizes the right of development to be closely linked to the environment by identifying the right to a healthy environment as a fundamental human right. Furthermore, by considering the establishment of international institutions, it integrated the process of global cooperation in the field of the environment. It provided the direction for the further development and evolution of the relevant international rules to protect the global environment.

Second generation: from the Stockholm Conference 1972 until the Rio Conference 1992Edit

According to the recommendation of the United Nations General Assembly[5], the International Conference on the Protection of the Environment was held from 5 to 16 June 1972 in Stockholm, the capital of Sweden. The Stockholm Conference was the largest international conference in which more than 6,000 people represented 113 countries, and about the same number, representatives of international organizations and 700 observers. Delegations from 400 international non-governmental organizations participated. The purpose of this conference was to pay attention to the world's environmental issues and their relationship with human rights, as well as to warn of the harmful effects of human activities on the environment.

The Stockholm Declaration of 1972 contained 26 principles. According to the declaration, environmental issues should be at the forefront of international concerns and marked the start of a dialogue between developed and developing countries on the link between economic growth, the pollution of the air, water, and oceans and the well-being of people around the world.[6]

The Action Plan contained three main categories: a) Global Environmental Assessment Programme (watch plan); b) Environmental management activities; (c) International measures to support assessment and management activities carried out at the national and international levels. In addition, these categories were broken down into 109 recommendations.[7]

Another important outcome of the conference was the establishment of an international body called the United Nations Environment Program (UNEP). UNEP is a United Nations-affiliated environmental protection program that has been one of the most important pillars of environmental protection in the world. One of the important tasks of UNEP is the Global Environmental Assessment, which publishes a collection annually that describes the state of the world's environment. UNEP is also coordinating and managing the world's environment in cooperation with the states worldwide. According to this mandate, UNEP does not have the right to directly interfere in the environmental affairs of other states, but all UNEP actions are carried out with the cooperation and participation of governments at the regional and global levels. This means that the United Nations allocates funds and credits to protect the environment of countries so that these countries can take the necessary measures to protect their environment.

Third generation: from the Rio Conference 1992 until the presentEdit

The third generation of International Environmental Law begins with the 1992 Rio Conference on Environment and Development[8]. The UN General Assembly approved holding an international conference on the environment and development. Accordingly, the Conference's preparatory committee was formed with the active participation of representatives of all member states and representatives of international organizations, both governmental and non-governmental. Subsequently, the United Nations Conference on Environment and Development was held on June 3, 1992, in Rio de Janeiro, Brazil, with the participation of more than 30,000 people from 176 countries, including 116 heads of state and representatives of 1,400 international non-governmental organizations working in the field of environment. In addition, the United Nations Framework Convention on Climate Change (UNFCC)[9] of New York in 1992 and the Convention on Biological Diversity (CBD)[10], drafted before the Conference, were opened in Rio for signature. Discussing the issue of the environment as a global problem, the Rio Conference stressed the need to coordinate the development process of countries with the protection of the environment and introduced environmental protection as an essential international issue for the next century. The proposal to establish international environmental regulations to achieve sustainable development marked a new turning point in the process of developing international environmental law. In addition, the Conference strengthened existing institutions and created new ones to coordinate further the international community's efforts to protect the environment within the framework of international institutions. Finally, the Rio 1992 Conference concluded with the adoption of three non-binding instruments, including the Conference Final Statement (one introduction and twenty-seven principles), Agenda 21[11] (Charter for the Future) and the Principles of Forest Conservation[12].

The Rio 1992 Declaration[13] affirms that States should always be concerned with the environmental preoccupations in economic development and industrial growth. They should consider sustainable development as an approach in their national development plans. The States should consider the "principle of sustainable development" in the formulation of programmatic and ordinary laws, as well as in the drafting of bilateral or multilateral binding instruments. They should recognize the role of social groups and non-governmental organizations in protecting the national, regional, and global environment.[3]

Another development of the international environmental law in this period is the organization of the World Summit on Sustainable Development, 26 August-4 September 2002, Johannesburg[14]. The Conference announced the eight Millennium Development Goals for development, including eradicating poverty and hunger, achieving universal primary education, promoting gender equality, women's empowerment, reducing child mortality, improving mothers' status, Fighting against AIDS, malaria, and other diseases.

Twenty years after the Earth Summit on Development and the Environment in Rio in 1992, and ten years after the Sustainable Development Conference in Johannesburg, the Rio + 20 Conference in Brazil is an essential step towards consolidating sustainability in It is the background of economic, social and environmental development. Therefore, the international community met again on June 20-22, 2012, in Rio de Janeiro to review the 20-year achievements of the Rio Conference in the direction of sustainable development and the prospects of the agreed programs. The Rio + 20 Conference, while emphasizing the commitments made at the Rio Conference of 1992, known as Agenda 21, seeks to introduce a new type of engagement in which business, governments and civil society are vital leaders for the protection of the global environment.

The Rio + 20 conference[15] was a new opportunity for the international community to conduct thorough deliberations on addressing existing barriers to the development of international environmental law. For example, one of the most significant events to achieve sustainable development in the last decade (from Johannesburg 2002 to Rio 2012) was identifying the causes of recession and economic crisis in the previous decade and combining economic issues with environmental criteria.

Another remarkable event in this period is the 2030 Agenda for Sustainable Development[16]. The purpose of this Agenda is a plan of action for sustainable development strengthening universal peace, eradicating poverty. The 17 Sustainable Development Goals and 169 targets demonstrate the scale and ambition of this new universal Agenda. It seeks to build on the Millennium Development Goals and complete what these did not achieve. It aims to realize the human rights of all and achieve gender equality and the empowerment of all women and girls. The Agenda create a balance between the three dimensions of sustainable development: the economic, social and environmental.

Therefore, the third period of the process of development of international environmental law could be called the period of realism, universalism, reforms. During this period, international environmental rules and regulations have evolved within the concept of sustainable development and, if necessary, have been amended to be in line with global realities and to be enforceable in practice, as well as to form new rules and regulations.

C. Principles of International Environmental LawEdit

International environmental law is generally based on legal principles affirmed in many declarations (soft law) and included in several conventions (hard law). These principles are very numerous and continue to develop in recent years. But some of them are important to be mentioned here:

I. Principle of sovereigntyEdit

The principle of sovereignty is one of the basic principles of international environmental law. In public international law, the principle of sovereignty is based on customary law. In Trail smelter case (United States v. Canada) of 16 April 1938 and 11 March 1941, the "Tribunal, therefore, finds that the above decisions, taken as a whole, constitute an adequate basis for its conclusions, namely, that, under the principles of international law, as well as of the law of the United States, no State has the right to use or permit the use of its territory in such a manner as to cause injury by fumes in or to the territory of another or the properties or persons therein, when the case is of serious consequence, and the injury is established by clear and convincing evidence."[17]

This principle also affirmed in Principle  21 of the 1972 Stockholm Declaration, according to this legal document: "States have, in accordance with the Charter of the United Nations and the principles of international law, the sovereign right to exploit their own resources pursuant to their own environmental policies, and the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other States or of areas beyond the limits of national jurisdiction"[18]

Moreover, the sovereignty of states has two bases; one is to recognize the sovereignty of states in the use of their natural resources, and the other is not to cause harm to other territories under the control of other states or areas that are not under the control of states, such as the high seas. The turning point in the principle of sovereignty is in Article 21 of the 1972 Stockholm Declaration, which, with a slight modification, was contained in the second principle of the Rio 1992 Declaration, which states: " States have, in accordance with the Charter of the United Nations and the principles of international law, the sovereign right to exploit their own resources pursuant to their own environmental and developmental policies, and the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other States or of areas beyond the limits of national jurisdiction."[19]

In the classical approach of public international law, the concept of sovereignty was based on independence and equal sovereignty with other states, which interpreted as a "absolute sovereignty" of the state. In this perspective, the power of the state is supreme, unlimited and non-subordinate. However, with the development of public international law, the sovereignty of states was reduced, and governments in some cases, in favor of international order, accepted some restrictions on their sovereignty, and from the twentieth century, the international community with respect In principle, the national sovereignty of states recognized a set of international rules such as human rights, environmental law and other international rules that limit the sovereignty of states.

The evolution of the concept of "sovereignty" in international environmental law demonstrates that States have the freedom to use their territory. Still, at the same time, they have obligations under which their activities should not harm other countries or regions beyond the limits of their sovereignty. The principle of sovereignty obligates all States to preserve and protect the environment in its entirety, both for States on their territory and areas outside any national jurisdiction, such as the high seas, Antarctica or outer space.

II. Principle of cooperationEdit

The principle of cooperation is a customary international obligation and one of the inseparable principles of the Charter of the United Nations. It is one of the features of contemporary international law. The principle of cooperation is binding in accordance with the Charter of the United Nations. Given its transnational nature, this principle is more necessary in international environmental law because the environment has no border.

Protection of the global environment is beyond the capacity of one or more States. It requires the international community's cooperation to prevent, reduce, and eliminate the harmful effects of environmental degradation and pollution. According to this principle, States have a duty to work together in all circumstances and in good faith to protect the environment. International cooperation could be considered in various fields such as information exchange, technology transfer, financial resources, participation in international conferences, and even emergency assistance through bilateral or multilateral agreements. Although each sovereign state is free to conduct its external relations according to what it considers to be its best interests, modern international law has developed a general obligation to cooperate with others to resolve problems that concern the international community as a whole.

The obligation of cooperating in environmental issues arises from the very existence of general public international law. More than a thousand international treaties recognize the need to collaborate with other states at different levels: bilateral, regional or global. In this context, the creation of numerous international organizations also corresponds to the need for institutional cooperation o environmental protection.

In addition to the general obligation of United Nations member states to cooperate in good faith with the organization and among themselves, the particular need to cooperate to preserve the environment is expressed in several legal instruments, including the soft law. Moreover, cooperation in international environmental law most often emerges in the context of international organizations, whether they already exist or are created for a particular environmental issue or sector.

Finally, due to the transboundary nature of the environment, states are obliged to cooperate in all circumstances in good faith to protect the environment.

III. Principle of Sustainable developmentEdit

Since the late 1980s, the term sustainable development has dominated environmental law and policy. In 1987, the World Commission on Environment and Development (WCED) published the «Our common future» report. The Brundtland Report stated that critical global environmental problems were primarily the result of the enormous poverty of the South and the non-sustainable patterns of consumption and production in the North. It called for a strategy that united development and the environment – described by the now-common term «sustainable development.» Sustainable development is defined as follows: «Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs[20] In 1989, the UN General Assembly debated the Report, which decided to organize a UN Conference on Environment and Development. The sustainable development principle presupposes that development policies should aim to eradicate poverty, improve economic, social and cultural conditions, preserve biological diversity, essential ecological processes, and life-sustaining systems. In addition, environmental conservation should be considered an integral part of the planning and carrying out activities at all stages.[21]

According to the principle, States should review national policies and plans in environment and development to enact effective laws and regulations that use economic instruments where appropriate and establish and strengthen institutional structures and procedures to integrate environment and development issues into all decision-making spheres fully. In addition, the integration of environmental, social and economic policies also requires transparency and broad public participation in decision-making by the authorities.

The principle of sustainable development is confirmed in many international legal instruments, including the Rio Declaration of 1992. The concept of sustainable development is an evolutionary process that meets the current generation's needs without diminishing the ability of the next generation to meet their needs, in other words, to provide an opportunity for everyone to live forever on the planet. Today, sustainable development is one of the most fundamental issues of international environmental law. Without a doubt, it can be named the primary goal of the development of international environmental law.[22]

However, the implementation of sustainable development confronted some challenges in its forms and contents. In terms of content, it lacks a comprehensive approach for including indigenous people, local cultures, good governance, consuming resources, producing goods and services, freedom of expression, employment, identifying the roots of poverty and gender discrimination.

IV. Principle of preventionEdit

The prevention of environmental degradation and pollution is regarded as the "golden rule" in international environmental law based on economic and ecological reasons. For instance, extinction of plant or animal species, soil erosion, loss of human life and leakage of pollutants into the sea create irreparable damage, in a way that, even when the damage can be compensated, restoring them to their previous state is not possible.[3]

V. Precautionary PrincipleEdit

This principle imposes a duty on states to prevent environmental damage.  Under this rule, a state may be obligated to take precautionary measures to prevent damage within its jurisdiction. The number of international environmental treaties confirms this duty of stats. In this perspective, Article 3 of the United Nations Framework Convention on Climate Change (UNFCC) states that: “The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects. Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing such measures, taking into account that policies and measures to deal with climate change should be cost-effective so as to ensure global benefits at the lowest possible cost”.[23]

VI. Principle of notificationEdit

This principle is one of the basic principles that can be traced back to the International Court of Justice from the 1949 Corfu Strait[24] case and other international sources such as environmental treaties and agreements. According to this principle, States have an obligation to notify other states in case of transboundary damages. There are also some other principles and concepts, such as the common heritage of humanity in international law and the rights of future generations.

D. Sources of International Environmental LawEdit

International environmental law is based on the two types of non-binding (soft) and binding (hard) sources:

I. Hard LawEdit

Hard law is a binding law that imposes obligatory rules and regulations on governments to take international responsibility in environmental issues. Therefore, it is essential to consider that the sources of international environmental law go beyond public international law.

Although the traditional sources of public international law apply to international environmental law, as mentioned in article 38 of the Statute of the International Court of Justice, the other sources also apply here, such as Jus Cogens rules (Peremptory norms of general international law)[25] , Erga Omnes obligations and obligatory resolutions of international organizations.  

II. Soft LawEdit

Soft law is a source that is not binding and has no specific warranties. These sources are including statements, resolutions, agendas, action plans, and the rules that guide governments. The primary purpose of soft law is to express the non-obligatory principles and rules that guide governments to protect the environment. It is essential to mention that even though these resources are not binding, they have a crucial impacts on the development of international environmental law. The most significant examples of these sources are the 1972 Stockholm Declaration, the 1982 Universal Charter of Nature, the 1992 Rio Declaration and Agenda 2030 for sustainable development. In addition, the soft law core idea is to affirm or declare general principles and define a guideline for states to protect their environment in a flexible manner.

Finally, the drafting and implementation of these sources of law allow governmental and non-governmental actors to cooperate together.

E. Global environmental problems and challengesEdit

Despite all global efforts, to develop binding and non-binding legal instruments, environmental concerns and threats such as global warming, climate change, desertification, and deforestation are not only remaining but also increasing.

Today's world's environmental concerns and threats go beyond the predictions of the experts and scientists present at Stockholm's first environmental Conference in 1972.

I. State sovereigntyEdit

Regardless of the concept of the sovereignty of states in international law, one of the main obstacles for the development of international environmental law, is the non-acceptance of governments, to delegate or limit their sovereignty, in favour of environmental organizations. Another conflict also exists between developed and developing countries, in enforcing regulations. For instance, according to the principle of Common but Differentiated Responsibilities, developed countries should take additional actions such as transferring technologies or contributing finance to developing countries, but this principal is not respected properly.

This principal clearly set out in many international environmental treaties such as United Nations Framework Convention on Climate Change (UNFCC). According to this convention, developed countries should provide financial resources to assist developing countries in implementing the objectives for protecting the climate change. ( )

II. Diversity of sourcesEdit

Another substantive challenge to developing international law is the diversity of binding and non-binding sources which is caused confusion and vagueness in implementation of international law.

III. Insufficient guarantee of implementationEdit

Many international rules and regulations, including multilateral treaties, are confronted with a deficiency of compliance mechanisms to protect the environment.

IV. Institutional challengeEdit

With the growing importance of global environmental protection since the 1972s, international governmental organizations, have tried to play their role in environmental protection.

As active subjects of international law, international organizations have a serious task to achieve in this regard.

One of the essential reflections holding the Stockholm Conference was establishing, the United Nations Environment Program as the global and executive arm for international protection of the environment. However, the UNEP has limited capacity to protect the global environment.

As a result, is it time to evaluate possibilities for creating a new organization for environmental protection like World Environmental Organization?

V. Emergence of new Challenges in the worldEdit

Environmental immigrants, ecological purposes refugees, environmental confrontations between states such as water war, international arms conflicts, ecocide and ecoterrorism are issues that have to discuss on another occasion.

F. Conclusion: Future of International Environmental LawEdit

Global challenges need global solutions: in this perspective, international cooperation between states plays a vital role.  Economic growth and increasing technological advances in the contemporary period have caused real damages to the environment.

The states should be willing to participate actively in drafting, signing, ratifying and implementing new treaties on environmental issues such as water pollution and climate change in the sustainable way.

It is also crucial to recognize the right of public participation in the environmental decision-making process and implementing. The right to “environment” and right to “economic development” as a “human right” should be considered in the concept of sustainable development as a common concern of humanity.

Now is the time for the international community to impose absolute responsibility or strict liability to states for any damage and harm to the environment at national and international level.  

Finally, international peace and security are necessary to ensure sustainable development for humanity, regardless in developed or developing countries.

Further ReadingsEdit

Table of ContentsEdit

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Part I - History, Theory, and Methods

Part II - General International Law

Part III - Specialized Fields


  1. a b Alexandre Kiss, Dinah Shelton, Guide to International Environmental Law, (Martinus Nijhoff Publishers, 2007)
  2. Alexandre Kiss and Dinah Shelton (1991), International Environmental Law, Ardsley-on-Hudson, NY. 575 pages. ISBN: 0-941320-67-7. Bulletin of Science, Technology & Society, 13(4), 243–243.
  3. a b c Abbas Poorhashemi, Emergence of International Environmental Law: as a new branch of International Public Law, (CIFILE Journal of International Law, Canada, V. 1, Issue 2, 2020, P. 33-39)
  4. Declaration of the United Nations Conference on the Human Environment, Stockholm, 16 June 1972.
  5. 1968 : Resolution E/RES/1346(XLV),
  6. United Nations Conference on the Human Environment, 5-16 June 1972, Stockholm,
  7. The Action Plan of the Stockholm conference,
  8. United Nations Conference on Environment and Development, Rio de Janeiro, Brazil, 3-14 June 1992,
  9. United Nations Framework Convention on Climate Change (UNFCC),
  10. Convention on Biological Diversity (CBD),
  11. Agenda 21,
  12. Report of the United Nations Conference on Environment and Development, Rio de Janeiro, 3 14 June 1992, vol. I, Resolutions Adopted by the Conference (United Nations publication, Sales No. E.93.I.8 and corrigendum), resolution 1, annex III.
  13. Rio 1992 Declaration,
  14. World Summit on Sustainable Development, 26 August-4 September 2002, Johannesburg,
  15. United Nations Conference on Sustainable Development, Rio+20,
  16. 2030 Agenda for Sustainable Development,
  17. Trail Smelter Arbitral Decision (United States v Canada) (1941), 3 RIAA 1905, 33:1 AJIL 182 & 35:4 AJIL 684,
  18. United Nations Conference on the Human Environment (1972),
  19. Rio Declaration on Environment and Development, 1992,
  20. Report of the World Commission on Environment and Development: Our Common Future,
  21. Poorhashemi, Abbas. "Quel développement pour le droit international de l'environnement au 21ème siècle?(What Development for International Environmental Law for the 21st Century?)." CIFILE Journal of International Law 2.3 (2021): 76-87.
  22. Virginie BARRAL, Le développement durable en droit international, Essai sue les incidences juridiques d’une norme évolutive, Bruylant, Bruxelles, 2016, p. 37.
  23. United Nations Framework Convention on Climate Change (UNFCC),
  24. Corfu Channel (United Kingdom of Great Britain and Northern Ireland v. Albania),
  25. Jus cogens, Peremptory norms of general international law,