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Summer 2023: Net Zero

The Back Page: Oceans

Samuel L Brown


  • Describes how climate change, pollution, resource extraction, overfishing, and infrastructure development are negatively impacting the oceans.
  • Sheds light on the “High Seas Treaty” as a landmark agreement to protect oceans from pollution and unsustainable fishing.
  • Explores the ocean as the planet’s “largest carbon sink” as it absorbs heat and carbon dioxide.
The Back Page: Oceans
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The oceans are often called the blue heart of the planet. Over 70% of the Earth’s surface is covered by the oceans, the oceans transport heat from the equator to the poles, regulating our climate and weather patterns, the ocean economy in the United States—the “blue economy”—produces over $400 billion in goods and services, and approximately 90% of all living space is contained within its depths.

The oceans are critical for life on Earth. However, the oceans face unprecedented challenges. Climate change, pollution, resource extraction, overfishing, and infrastructure development are just a few of the issues impacting the oceans. The oceans are sometimes overlooked, but the emerging issues and associated legal frameworks will be critical to the holistic practice of environmental law in the future.

In regards to climate change, the oceans act as the planet’s largest carbon sink, absorbing heat and carbon dioxide (CO₂). However, with the increase in global temperatures and levels of CO₂ in the atmosphere, summer 2023 has seen record levels of surface temperatures—approaching 100ºF in some locations—and increases in ocean acidity, coral bleaching, and sea-level rise.

As part of the effort to meet international, national, and corporate climate change mitigation and energy transition goals, the oceans are seen as part of the solution. Offshore wind projects in the Atlantic and Pacific Oceans and the Gulf of Mexico are on the horizon, the construction of coastal export terminals are being prepared to ship green hydrogen and ammonia across the globe, and subsea geologic formations are being explored to sequester CO₂ via carbon capture and storage hub projects. None of these ocean-focused projects are without certain levels of opposition, and emerging legal frameworks and litigation trends will likely develop quickly in the short term.

As an example, deep sea mining—removing mineral deposits and metals from the ocean’s seabed—illustrates the nexus between climate change mitigation and the oceans. Critical minerals such as cobalt and lithium are currently necessary for energy transition technology like batteries for electric vehicles; but there are geographic limitations on reaching these minerals terrestrially. Deep sea mining of these minerals is being explored as a solution to the supply chain bottlenecks and geopolitical constraints on existing sources. The United Nations Convention on the Law of the Seas governs the international ocean floor and the International Seabed Authority, the United Nations (UN) body that regulates the world’s ocean floor, is being pushed to develop regulations and permitting standards for deep sea mining. Some companies and countries are pledging to avoid minerals mined from the oceans or have called for a ban, pause, or moratorium on deep sea mining until environmental safeguards are in place, while other countries and companies are pushing ahead.

In a related development, after decades of negotiations, this summer the UN agreed on what is being called the “High Seas Treaty.” A landmark marine biodiversity agreement, the treaty focuses on protection from pollution and unsustainable fishing activities outside national jurisdictions and linking the treaty’s objectives with the UN’s Sustainable Development Goals. The timing and the substance of the High Seas Treaty illustrates the global importance of the oceans, the shifting currents associated with the applicable legal frameworks, and the importance of the interrelationship between the oceans and climate change, biodiversity, and health of the planet.