Thirty years ago, I had the privilege of seeing the deep ocean up close. For my Ph.D. research, I dropped 1.5 miles in the Alvin submersible above the East Pacific Rise, southwest of Acapulco. Beyond illuminating the oceanographic process I was studying — the connection between plate tectonics, volcanic eruptions and deep-sea vents — that one shaft of ocean opened my eyes to a larger truth: Humans are largely blind to this enormous and lively part of the world — more than two-thirds of the Earth.

It is worth repeating that scientists know more about Mars, Venus and the dark side of the moon than they know of Earth’s ocean depths. To date, less than 20% of the ocean floor has been mapped — 13% in just the past four years. But with the right support, scientists could map it all by 2030. It’s an essential undertaking, but it’s going to take dedicated effort, public support and government funding. Such a project can be accomplished only through global cooperation. 

The payoff stands to be tremendous — for everything from ship navigation to climate modeling. A clear view of the ocean floor’s topography would allow for optimal siting of undersea cables and offshore wind turbines. It would show where deep-ocean fishing can be done safely, and where it cannot. With a three-dimensional understanding of ocean volume, meteorologists could better understand how typhoons and tsunamis travel and intensify as they cross the ocean, bringing storm surges to the shoreline, and climate scientists could more precisely measure the circulation of heat in the ocean and thus build better models of climate change.

Climate change is the most basic and urgent reason to map the ocean as quickly as possible. Healthy oceans play an outsized role in minimizing climate change, because they capture carbon emissions. But this capacity has limits. Excess carbon acidifies ocean waters, making life difficult for coral reefs and shellfish (oysters, mussels, snails, clams). It also lowers the oxygen content of the water, impairing the ability of all sea life to breathe. Human practices that disturb the ocean floor — chiefly trawl fishing — make matters worse by releasing carbon from the ocean floor. Deep-sea mining, if it is allowed to go forward unmanaged, would have a similar effect, and further disturb undersea ecosystems.

To measure the progress of climate change and to study the ocean processes and human activities that affect that progress, it is essential to assemble a detailed picture of the undersea world.

Scientists have the technology to get the job done. Today’s sonars are sensitive enough to map features of ocean water above the seafloor, including wave action, schools of fish and changes in coral reefs that can indicate marine oxygen levels. The geographic information system technology that I and others use can analyze data from an array of sources — including sonar, satellites, submersible craft and underwater cameras — to put together a three-dimensional picture of the underwater world and study how best to manage and protect it.

The Seabed 2030 initiative, an effort sanctioned by the United Nations and supported by the Nippon Foundation to map the ocean floor, has collected bathymetric (depth) data from governments and other data owners. Sensors carried aboard transoceanic cruise ships and cargo ships have gathered more data. And robots have been engaged to survey the ocean floor, similar to the way robots have been used map the surface of Mars and other planets.

To finish the job in due time, though, the initiative will require an extended commitment and further funding. Private-sector partners are chipping in, including Vulcan, a philanthropic company founded by the late Paul Allen of Microsoft, and the Schmidt Ocean Institute, launched by Wendy Schmidt and Eric Schmidt of Google. But the amount of work ahead requires the kind of funding that only governments can provide.

Larry Mayer, the director of the Center for Coastal and Ocean Mapping at the University of New Hampshire, has calculated that $3 billion to $5 billion will be needed to finish this job. It’s a big price tag, but compare it with outlays for space travel and exploration — NASA is spending nearly $3 billion on the Perseverence Mars rover — and the value for dollar is obvious. All the major seagoing science powers of the world — including the U.S., the U.K., France, Germany and China — must contribute.

Climate change, so vividly illustrated by this summer of fire and floods on land and documented by the IPCC’s new report, has much increased the urgency to see the entire ocean in detail. The job can be done by the end of this decade if countries step up to the challenge.

(Corrects the cost of the Mars Perseverance rover in the second-to-last paragraph.)

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Dawn Wright is the chief scientist of Esri, a professor of geography and oceanography at Oregon State University, and a member of the National Academy of Sciences. Her book “GIS for Science: Maps for Saving the Planet” will be published in October.

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