Welcome to the Global Commons!

Hello Geographers! This chapter is all about resources that belong to everyone and no one at the same time. Think of it as the world's shared property. These areas are crucial for humanity, but managing them presents some of the biggest challenges in global governance.
We are focusing here on how global systems (like trade and politics) interact with these shared spaces, particularly the vast oceans. Let's dive in!

Quick Review: Context

This topic sits within the Global systems and governance section, meaning we look at how different countries (states), economies, and international rules try to manage shared global issues.

1. Understanding the Concept of the Global Commons (3.2.1.5)

The concept of the 'global commons' refers to natural resources or areas that are geographically outside the jurisdiction of any one nation state. This means they are theoretically accessible to all states.
Think of these areas like a shared public park—everyone has the right to use it, but everyone also has a responsibility to maintain it.

The Four Traditional Global Commons

Traditionally, four main domains are classified as the global commons:

  • The High Seas: The areas of ocean beyond the Exclusive Economic Zones (EEZs) of coastal states.
  • The Atmosphere: The envelope of gases surrounding the Earth (crucial for climate regulation).
  • Antarctica: Protected by international treaties (specifically the Antarctic Treaty System).
  • Outer Space: Governed by the Outer Space Treaty.
Rights and Responsibilities

The core philosophy behind the global commons is two-fold:

  1. Rights of all to the benefits: All people have the right to access and benefit from these resources (e.g., resources from the sea, a stable climate from the atmosphere).
  2. The need for protection: To ensure the benefits are available indefinitely, the rights of all people to sustainable development must acknowledge the need to protect the global commons.
    This is the classic dilemma: how do we use these resources without destroying them?

Quick Takeaway: The Global Commons are areas outside national control. We all have the right to use them, but we must protect them for the future (sustainable development).

2. The Oceans as a Global Common (3.2.1.6)

The world's oceans (including the Atlantic, Pacific, Indian, Arctic, and Antarctic) are the largest and perhaps most complex example of a global common. They cover over 70% of the Earth’s surface and are incredibly vulnerable to global economic pressures and environmental change.

2.1 Contemporary Geography of the Oceans: Physical Features

Understanding the ocean's role requires knowing its basic physical geography. These features define where resources are found and where life thrives:

  • Continental Shelves: Shallow, submerged extensions of the continent. They contain most of the world's fishing grounds and oil/gas reserves.
  • Continental Slopes: The steep drop-off marking the boundary between the continental crust and the oceanic crust.
  • Abyssal Plains: Flat, deep ocean floors, usually 3,000 to 6,000 metres deep.
  • Mid-Ocean Ridges: Underwater mountain systems formed by plate tectonics (constructive margins), where new crust is created. Did you know? The Mid-Atlantic Ridge is the longest mountain chain on Earth!
  • Trenches: Deep, narrow depressions on the seafloor, often found near destructive plate margins (subduction zones).
  • Volcanic Arcs: Chains of volcanoes formed above subducting plates, often forming island chains.
  • Coral Reefs: Biodiverse underwater structures made of calcium carbonate secreted by corals, found in shallow tropical waters.
2.2 Vertical Ocean Zones (The Pelagic Zones)

The water column itself is layered into zones based primarily on light penetration and depth. These zones dictate the type of life supported:

  • Epipelagic Zone (Sunlight Zone): 0m to 200m. Enough light for photosynthesis. Home to most marine life.
  • Mesopelagic Zone (Twilight Zone): 200m to 1,000m. Some faint light, but not enough for photosynthesis.
  • Bathypelagic Zone (Midnight Zone): 1,000m to 4,000m. Complete darkness. Life relies on food falling from above.
  • Abyssopelagic Zone (The Abyssal Zone): 4,000m to 6,000m. Vast, extremely cold, high-pressure environment.
  • Hadalpelagic Zone (Trenches): Below 6,000m (not always listed, but useful to know as the deepest part).

Memory Aid: Remember the zones by light: Epi (sun), Meso (twilight), Bathy (midnight), Abyss (deep darkness).

3. Threats to the World’s Oceans

Because the oceans are the ultimate shared resource, they suffer from intense pressure driven by global economic activity. Here are the key threats identified in the syllabus:

3.1 Climate Change

This is a double threat driven by rising CO2 levels:

  • Ocean Warming: Leads to rising sea levels (thermal expansion and melting ice) and the destruction of temperature-sensitive ecosystems, such as mass coral bleaching.
  • Ocean Acidification: The ocean absorbs excess atmospheric CO2, forming carbonic acid. This reduces pH levels, making it harder for organisms (like corals and shellfish) to build their protective shells.
3.2 Fishing and Whaling (Overexploitation)

Unregulated fishing in the high seas leads to the depletion of fish stocks beyond their ability to recover.

  • Overfishing: Many commercial fish populations (like tuna and cod) have been severely reduced due to industrial fishing fleets that operate globally.
  • Whaling: Though heavily regulated by bodies like the International Whaling Commission (IWC), some countries continue whaling under scientific pretexts.
3.3 Pollution by Oil and Plastics

Pollution threatens marine life at all levels of the food chain:

  • Plastic Pollution: Non-biodegradable plastics break down into microplastics, which are ingested by marine life. Large accumulations, like the Great Pacific Garbage Patch, highlight this global crisis.
  • Oil Spills: Large accidental spills (e.g., Deepwater Horizon) cause catastrophic, localized environmental damage, killing birds, fish, and mammals.
3.4 Shipping, Trade, and Tourism

The global movement of goods and people across the oceans causes damage:

  • Habitat Destruction: Ship anchors and dredging for ports damage coastal ecosystems like mangroves and coral reefs.
  • Invasive Species: Ships' ballast water (used for stability) often contains foreign organisms, which are then dumped in new ports, threatening local biodiversity.
  • Noise Pollution: The loud engines of large ships disrupt the communication and navigation systems of marine mammals like whales.

Quick Takeaway: The main threats are environmental (climate change, pollution) and resource overexploitation (fishing), driven by global economic activities.

4. Governance of the Global Commons

Since no single country owns the high seas, governance relies on international cooperation, laws, and institutions. This is a crucial element of Global governance (3.2.1.4).

4.1 International Government Organisations (IGOs)

IGOs are established by treaties between governments to manage shared concerns:

  • United Nations Convention on the Law of the Sea (UNCLOS):
    Purpose and Scope: Often called the "Constitution of the Oceans." It defines maritime zones, including the Exclusive Economic Zone (EEZ), extending 200 nautical miles from shore, where coastal states have special rights over marine resources.
    Inspection/Enforcement: While UNCLOS provides the legal framework, enforcement relies heavily on member states' naval and coast guard forces, which can be weak in the high seas.
  • International Maritime Organisation (IMO):
    Purpose and Scope: A UN specialised agency responsible for measures to improve the safety and security of international shipping and to prevent marine pollution from ships (e.g., through conventions like MARPOL).
    Inspection/Enforcement: Uses port state control and flag state responsibilities to ensure ships comply with international standards.
4.2 The Role of Non-Governmental Organisations (NGOs)

NGOs operate independently of governments and play a vital role in monitoring, advocacy, and direct action:

  • Monitoring Threats: NGOs like Greenpeace or WWF conduct research to expose illegal fishing or environmental damage.
  • Enhancing Protection: They pressure IGOs and national governments to implement stricter regulations and create marine protected areas (MPAs).
  • Marine Stewardship Council (MSC):
    This is an international non-profit organisation that runs an ecological certification and labelling program for sustainable seafood. Its blue label tells consumers that the fish was caught sustainably, thereby incentivising responsible fishing practices.
4.3 Geographical Consequences of Ocean Governance

The success or failure of governance impacts people and places globally:

  • Benefits and Stability: Effective governance (like UNCLOS defining EEZs) promotes stability by reducing conflict over maritime borders and resources, supporting global trade routes, and providing legal security for coastal citizens who depend on the oceans.
  • Inequalities and Injustices: Global fishing governance often favours large, developed nations that have the technology and capital to operate vast deep-sea fleets. Smaller, less developed nations may find their coastal fish stocks depleted by foreign vessels operating just outside their EEZs. This leads to food security issues and economic disparity.

Key Takeaway: Governance is complex, relying on international law (UNCLOS), specific industry regulation (IMO), and non-state actors (NGOs/MSC). Enforcement remains a major difficulty, often leading to inequalities in resource access.

Study Checklist and Common Mistakes

For Exam Success:

  • Be specific: When discussing oceans, mention *which* zone or *which* feature is affected by a particular threat (e.g., pollution affects the Epipelagic Zone; deep-sea mining affects the Abyssal Plain).
  • Link back to Global Systems: Remember that climate change, overfishing, and pollution are all driven by global economic flows (trade, capital, demand for resources).
  • Don't confuse IGOs and NGOs: IGOs (UNCLOS, IMO) are government-backed treaties/bodies; NGOs (MSC, Greenpeace) are independent groups, often focused on certification or activism.


You’ve mastered the Global Commons! This is a high-level topic that bridges physical geography (ocean features) with human geography (governance and conflict). Keep up the great work!