Climate planning: Why India needs its very own body of research on marine carbon removal

That instinct is useful as a new climate conversation takes shape globally: marine carbon dioxide removal (mCDR). It is not something India is being asked to deploy. At this stage, it is simply a scientific inquiry—one that matters because we are a coastal nation with strong marine-science institutions and communities whose lives are deeply tied to the ocean.

But first, it’s worth stepping back to look at the broader climate equation. The science is clear: to contain temperature rise, the world must do two things at the same time: cut emissions sharply and remove some of the carbon already in the atmosphere. Think of these as two oars of the same boat. Row with only one and you simply spin in circles.

Most of the attention, appropriately, goes to emissions cuts: cleaner energy, better transport and more efficient industry. But the world is also exploring different ways of removing carbon. Some are land-based, like trees, biochar or enhanced weathering. And some, more recently, involve the ocean.

The reason the ocean enters this conversation at all is because it is already the world’s largest active carbon sink. Since the start of the industrial age, it has absorbed about 30% of all the carbon dioxide humans have released. It is doing a huge amount of climate work simply through natural chemistry and biology. That alone makes it reasonable to ask: Can we understand these natural processes better, and, if it proves safe and effective, help them along slightly?

There are two broad ideas.

One is about chemistry. When the ocean becomes slightly more alkaline (less acidic), it naturally converts carbon dioxide into stable forms that can stay locked away for a long time. Some approaches try to help this process along by adding small amounts of alkaline minerals—the same kind found in rocks and shells—to seawater in controlled settings.

The other is about biology. Ocean life already moves carbon from the surface to deeper waters. For example, seaweed grows by absorbing carbon. If some of that seaweed sinks naturally to deeper layers, the carbon stays out of the atmosphere for long periods.

Similarly, tiny marine plants—the microscopic equivalent of grass in the sea—take up carbon when they grow. Under the right conditions, they can move some of that carbon downwards. mCDR studies try to understand whether these natural pathways can be gently supported without harming marine ecosystems.

None of this is ready for wide use across the world. We still do not know whether it works reliably at the scales that matter, whether it’s environmentally safe, or whether it will ever be affordable. Early carbon-removal credits from such methods have been extremely expensive. In short, this is not yet a technology ready to deploy—it is a field of science to understand. And this is where India comes in.

Our seas are not like anyone else’s. The Arabian Sea, Bay of Bengal, monsoon-driven currents, warm waters, nutrient patterns, fisheries, sediment flows—these conditions are unique. What works (or fails) in the cold open waters of the North Atlantic may tell us very little about what might happen here. We need our own body of research evidence, not borrowed conclusions.

We also have the scientific capacity to generate it. Institutions like the Indian National Centre for Ocean Information Services, National Institute of Ocean Technology, National Institute of Oceanography, Physical Research Laboratory and several Indian Institutes of Technology already run advanced ocean models, observation systems and coastal research programmes.

What they need is not a leap of faith into climate engineering, but a small, steady investment in early-stage research: controlled experiments, environmental assessments and careful monitoring.

There is a second reason: studying mCDR strengthens the science we already need.

Whether or not mCDR ever becomes a useful climate tool, the questions it asks—how marine ecosystems respond to minerals, nutrients or biomass—are the ones we need to understand fishery shifts, algal blooms and coastal resilience. In other words, researching mCDR can improve our understanding of the oceans in ways that matter far beyond carbon removal.

Finally, this is a matter of literacy and readiness. Exploring mCDR does not commit India to deploying it. But it ensures that if global science progresses—in either direction—we are not the last to understand it. Our regulators, coastal administrators and carbon-market institutions would be prepared. Our coastal communities would be included early, not informed late. Our diplomacy would be grounded in data, not dependence. Sometimes leadership is not about being early. It is about being prepared.

India does not need to champion mCDR. But as a coastal nation with strong scientific institutions, the sensible path is of organized inquiry. The climate will continue to change whether we study these questions or not. The choice is simply whether India wants to rely on other people’s science to guide the future of our coasts or acquire its own.

The author is director, Environmental Defense India Foundation.