The Rockefellers, who made their vast fortune on oil, and other philanthropies and high-wealth individuals on Monday will announce pledges to divest a total of $50 billion from fossil fuel investments.

The Global Divest-Invest coalition will announce new pledges and members one day before 120 heads of state address the United Nations on how their countries will contribute to a global effort to halt a dangerous rise in temperatures.

Since the divestment movement launched three years ago, some 650 individuals and 180 institutions, including 50 new foundations, which hold over $50 billion in total assets, pledged to divest from fossil fuels over five years using a variety of approaches.

One of the signatories is the Rockefeller Brothers Fund. Stephen Heintz, an heir of Standard Oil tycoon John D. Rockefeller, said the move to divest away from fossil fuels would be in line with his wishes.

“We are quite convinced that if he were alive today, as an astute businessman looking out to the future, he would be moving out of fossil fuels and investing in clean, renewable energy,” Heintz said in a statement.

Since January 2014, commitments by campuses, churches, cities, states, hospitals, pension funds, and others in the United States and abroad doubled, from 74 to 180, according to philanthropic giving consultancy Arabella Advisors.

One of the higher profile education institution divestments came in May, when Stanford University said it will no longer use any of its $18.7 billion endowment to invest in coal mining companies.

While some smaller liberal colleges have made divestment announcements, some larger institutions have been reluctant.

The University of California voted last week to maintain its investments in fossil fuels, frustrating a student-led effort to divest its portfolio in oil, natural gas and coal.

South African Archbishop Desmond Tutu, an anti-Apartheid figure who has been a strong voice on the need for economic divestments, will add to Monday’s announcements in a recorded video announcement in which he will call for a freeze on all new fossil fuel exploration.

“We can no longer continue feeding our addiction to fossil fuels as if there is no tomorrow, for there will be no tomorrow,” he said.