Emissions from the 88 largest fossil fuel companies are responsible for more than half of all ocean acidification since pre-industrial times

The oceans are literally dissolving. Since the industrial revolution began, the pH of seawater has dropped by approximately 30 percent—a seemingly modest number that masks a catastrophic shift in chemistry threatening marine life from coral reefs to shellfish beds. Now we know who bears primary responsibility for this invisible crisis, and the answer points directly at the world's largest fossil fuel producers.

A peer-reviewed study published in Environmental Research Letters calculated that emissions traced to just 88 of the world's largest gas, oil, coal, and cement companies are responsible for more than half of all ocean acidification since pre-industrial times. These 88 corporations—a fraction of the industry—created the conditions for a chemical transformation that took millennia to occur naturally, compressed into barely two centuries.

When researchers first began connecting corporate emissions to ocean acidification, the industry's response followed a familiar playbook. Fossil fuel companies and their allies questioned the science, demanded more studies, and suggested the problem was overstated. They funded think tanks that cast doubt on the acidification research itself, creating just enough confusion in the public mind to delay meaningful action. This strategy wasn't new—it was refined over decades of experience.

What made this claim difficult to dismiss, however, was the underlying research methodology. Scientists didn't rely on corporate self-reporting or estimates. They traced specific emissions from particular companies through atmospheric records, calculating their contribution to carbon dioxide accumulation and the resulting chemical reactions in seawater. The data was granular and verifiable. When carbon dioxide dissolves in ocean water, it forms carbonic acid—basic chemistry that cannot be argued away.

The Smithsonian Institution's documentation of ocean acidification confirmed the phenomenon's reality and scope. Coral bleaching events, shell dissolution in pteropods, and disrupted larval development in commercial fish species all track directly to declining ocean pH. These weren't theoretical harms—they were observable, measurable impacts on ecosystems and food chains that humans depend upon.