John D. Rockefeller. (Photo: Anonymous/Public Domain)

Descendants of John D. Rockefeller, who made a fortune from Standard Oil and was the richest person in U.S. history, are getting out of the oil business. 

They’re divesting themselves of all of their holdings in fossil fuels, in fact, writing in a statement on the website for the Rockefeller Family Fund that continued oil exploration threatens us all. 

“We must keep most of the already discovered reserves in the ground if there is any hope for human and natural ecosystems to survive and thrive in the decades ahead,” reads the foundation’s statement, posted Wednesday. ”There is no sane rationale for companies to continue to explore for new sources of hydrocarbons.”

At its height, Standard Oil controlled over 90 percent of the oil production in the U.S., affording Rockefeller immense wealth. But the Supreme Court ruled in 1911 that it was an illegal monopoly, and the company was broken up into dozens of smaller companies, including, among many others, Exxon. 

The modern descendant of that company, ExxonMobil, was harshly criticized in the Rockefeller Family Fund statement, leading, perhaps inevitably, to a pretty messy divorce. 

“It’s not surprising that they’re divesting from the company since they’re already funding a conspiracy against us,” a spokesman for the ExxonMobil tells Bloomberg.

In today’s currency, John D. Rockefeller would have been worth around $340 billion dollars at his height, though it’s unknown how much of that fortune—much of which has gone to a range of philanthropic organizations—still exists. 

“Needless to say, the Rockefeller family has had a long and profitable history investing in the oil industry, including ExxonMobil,” the Rockefeller Family Fund wrote. “But history moves on, as it must.”