Greenpeace’s Melita Steele said at Monday’s protest in Johannesburg that her environmental group wants South Africa to stop ongoing construction of a coal power station and “shift investment to renewal energy and energy efficiency.”

A spokeswoman for Eskom, South Africa’s state-owned electricity company, did not immediately return a call seeking comment.

South Africa is the only African nation among the 20 countries that emit nearly 90 percent of the world’s greenhouse gases. Officials here have a long-term plan to reduce dependence on coal, but say that in the short term the country needs polluting technologies to develop.