WHOI Plans Geoengineering Experiment To Combat Climate Change In Waters Off Nantucket

Starting this August, the Woods Hole Oceanographic Institution will conduct a small-scale study on the effects of ocean alkalinity enhancement, a process that artificially increases the pH of ocean water to combat human-caused ocean acidification. The experiment will be conducted in the waters southwest of Nantucket and Martha’s Vineyard.

Dubbed the “LOC-NESS” project - short for Locking away Ocean Carbon in the Northeast Shelf and Slope - the experiment involves the dumping of 20 metric tonnes of sodium hydroxide (also known as lye and caustic soda) and up to 75 kilograms of tracer dye into the ocean followed by five days of on-site, 24-hour monitoring of alkalinity dispersal, CO2 uptake, and environmental impacts.

The experiment will be “one of the first of its kind in the world, and the first of its kind in the Northeast United States.”

If successful, ocean alkalinity enhancement could increase the ocean’s ability to remove carbon dioxide from the atmosphere, lessening the effects of climate change. As the world’s biggest carbon sink, the ocean is a key part of the fight against climate change, and a more alkaline ocean can sequester more carbon—and is healthier for aquatic life. Carbon dioxide interacts with naturally occurring chemicals in ocean water to form bicarbonate, which can store carbon dioxide longer than most biological sinks. By pouring sodium hydroxide into the water, Woods Hole hopes to test whether humans can boost ocean alkalinity and reduce atmospheric carbon dioxide in one stroke.

“Given society’s current emissions trajectory, it has become clear in recent years that major emission reductions must now be supplemented by efforts to actively remove existing carbon dioxide from the atmosphere,” according to the study proposal. “Supplementing emissions reductions with carbon dioxide removal, or CDR, is becoming a critical strategy for meeting internationally accepted climate mitigation targets outlined in the Paris Climate Agreement and reaffirmed at the conclusion of the COP28 UN climate conference in Dubai.”

However, some environmental groups opposed to human intervention in the environment, often referred to as geoengineering, object to the study’s methods. Friends of the Earth has equated the Woods Hole study to pouring 60,000 gallons of bleach in the ocean and castigated the Environmental Protection Agency for permitting it. They also contend that because tracking the effects of ocean alkalinity enhancement is so difficult, the Woods Hole Oceanographic Institution will not learn much from the study.

For their part, Woods Hole and the EPA claim that the study is safe. In a press release, the EPA said that it “does not anticipate any measurable environmental or other impacts beyond the monitoring periods of the study” and Woods Hole’s website stresses that because of the purity of sodium hydroxide, “the effects on water quality are limited only to the effect on pH.”

Sodium hydroxide is commonly added to drinking water to reduce acidity and is often used in baking. Because the sodium hydroxide needs to stay on the surface to interact with the atmosphere and draw down carbon dioxide, researchers don’t anticipate it will sink more than 10 meters, or 32 feet, in the water column before dispersing. They believe there will be no impacts on marine ecosystems.

Geoengineering opponents are skeptical of the scientists’ confidence and warn that human interventions in the environment often have unintended consequences.