South Africa relies on coal to generate much of its electricity. State utility Eskom has previously said it plans to cut emissions by reducing its reliance on coal and to expand future power output using mainly nuclear power stations.
"They need to spend more money not in nuclear power, but in renewable energy and energy efficiency," Amadou Kanoute, executive director of Greenpeace Africa, told Reuters.
The environmental group's office will be in Johannesburg, South Africa's commercial capital.
South Africa's government has said it aims to brake rising emissions. It presents a scenario under which emissions will rise until 2020-25, stay flat for up to a decade and then fall. It will set mandatory energy efficiency targets and a gradual shift away from coal.
A U.N. Climate Panel report last year, projected that up to 250 million people in Africa would be living in areas of stress on water supplies by 2020.
The lobby group said it had opened an office in Johannesburg as a first step to address climate change, deforestation and overfishing in Africa. It plans to open a second office in the Democratic Republic of Congo this month and another in Senegal next year.
"Africa is in a position to leapfrog dirty development and become a leader in helping to avert catastrophic climate change and protect the natural environment. We are here to help make that happen," Kanoute said.