Archbishop Emeritus Desmond Tutu has urged the University of Cape Town to drop investment in polluting fossil fuels because of their contribution to climate change, which is heavily affecting the world's poorest people.

The former Anglican archbishop of Cape Town and Nobel Peace Prize laureate has encouraged the South African university to follow the example of many colleges and universities in the United States.

A number of U.S. institutions have moved their money away from fossil fuels and directed it to low-carbon projects, Blue & Green Tomorrow, a British climate advocacy group said in a statement.

In a letter to UCT, Tutu said, "It is the world's wealthiest countries and people who have benefited most from the use of fossil fuels, and have contributed most to global warming.

"It is time we took full responsibility for our past actions."

Tutus' call came before the formal launch of a campaign at UCT, one of South Africa's universities, on the issue, planned for a public meeting on July 30.

He said people of conscience need to sever their ties with corporations financing the injustice of climate change.

"I ask UCT to examine urgently the extent of your investments in fossil fuel companies and to make a strong commitment to phasing them out as soon as possible," said Tutu in his letter to one of South Africa's top universities.

Tutu had previously called on governments, universities and religious institutions to divest from dirty energy companies in an apartheid-style boycott, similar to those done with South African firms during the years of racial segregation.

The divestment call has been backed by divestment group 350.org. "If it is wrong to wreck the climate, then it is also wrong to profit from that wreckage," said Ferrial Adam, team leader for Africa and Arab world at 350.org.

"Coal and fossil fuels need to stay in the ground if we are to have any chance of reducing CO2 emissions, minimise global warming and prevent more Africans being affected by rising temperatures and increases in drought and flooding."

He said Arica would be hardest hit by the impacts of climate change so it was right that fossil fuel divestment campaigns have now reached the continent.

"This is just the beginning."

Increasing numbers of religious and higher education bodies have backed the case for fossil fuels divestment, not only on environmental but also financial grounds.