When we think about the Internet, we often imagine satellites and Wi-Fi signals floating through the air. But the real workhorses of global connectivity lie hidden beneath the ocean’s surface. Subsea cables — powerful lines stretching across the seafloor — carry over 99% of international Internet traffic, making the world more connected than ever before.
Yet as critical as they are, subsea cables face growing challenges. Climate change, regulatory complexities, and sustainability demands are reshaping how the industry operates. Researchers like Nicole Starosielski, Professor at the University of California, Berkeley, in collaboration with the SubOptic Foundation and supported by the Internet Society Foundation’s Research and Resiliency Grant Programs, are leading the way in understanding and securing this invisible network.
On World Oceans Day, we dive deeper with Nicole to understand why these cables matter, how they impact the environment, and what the future holds for this underwater infrastructure that keeps the Internet alive.
Internet Society Foundation: What was the objective of your research on subsea cables?
Nicole Starosielski: The objective of the Sustainable Subsea Networks project, funded by the Internet Society Foundation, is to focus on enhancing the sustainability of subsea telecommunications cables, which currently support over 99% of transoceanic Internet traffic. The research explores how sustainable these systems are, conducting the first academic peer-reviewed carbon footprint analysis of subsea cables to identify emission sources and best practices within the industry.
ISF: How exactly do subsea cables support Internet traffic, and what did you learn about their environmental impact?
Subsea cables are the backbone of the global Internet. When you send an email or hop on an international Zoom call, your data likely travels across the ocean floor. Although cables sit on the seabed, multiple peer-reviewed studies show that their environmental impact is relatively benign compared to other infrastructures. Emissions are generated not from the seabed itself but from the manufacturing and maintenance processes, such as where the steel is sourced or how often ships must repair damaged cables. The direct ecological footprint is small, but improving sustainability in production and operations offers real opportunities for reducing the overall impact.
ISF: What challenges did you uncover in the effort to make these networks more sustainable?
The challenges span the entire life cycle of the cable. Sourcing materials from environmentally responsible suppliers, improving installation practices, and protecting cables from damage all help reduce emissions. However, aspects like upgrading the shipping fleets used for installation and maintenance depend on broader changes in maritime infrastructure — something beyond the cable industry’s control. At the end of their life, cables can be recovered and recycled, contributing to a circular economy and further minimizing environmental impacts.
ISF: Subsea cables seem critical yet invisible. How has the industry responded to sustainability efforts?
It’s a small, tight-knit sector where people know each other and genuinely care about their work. Though historically less public-facing than other tech sectors, the subsea cable industry has embraced sustainability initiatives. Through partnerships and networks, companies are collaborating independently to share best practices and develop sustainable solutions. This community-driven effort is gaining traction and momentum beyond just the Sustainable Subsea Networks project.
ISF: Navigating the regulations around subsea cables must be complex. What have you found in terms of governance?
It’s definitely complicated. Cable ships are regulated under the International Maritime Organization, but national laws govern cable landings, and regions like the European Union have their own environmental standards. Building a global, sustainable Internet requires negotiating many different regulatory regimes — and they are constantly evolving. There’s no uniform global approach yet, making it a significant challenge for long-term sustainability planning.
ISF: How did working across academia, industry, and policy shape your research outcomes?
Academic research must engage with practice and policy. Otherwise, it risks staying confined to academia and never impacting the real world. In this project, industry stakeholders have been incredibly receptive. They recognize that research can play an important role in shaping the future of the subsea cable sector. The partnership model, supported by the Internet Society Foundation, helped bridge gaps between academic theory and industry practice.
ISF: What made this project possible?
This research would not have happened without the Internet Society Foundation. Their support enabled the launch of an independent but collaborative project that the SubOptic Foundation could use to elevate sustainability efforts across the subsea cable industry. It also helped the industry itself see the value of research, not just as a theoretical exercise but as a tool for real-world impact.