More provinces in South Africa, including prosperous Gauteng where Johannesburg and Pretoria, are located could become malaria zones by 2050 due to global warming, the environment minister said, quoting a new report.

Plants and animal species are also at risk of being wiped out in South Africa due to climate change, the South African National Biodiversity Institute (SANBI) said in a report on the impact of climate change on South Africa.

"The research presented today by SANBI shows, for example, that climate change could lead to provinces like Mpumalanga, Limpopo, the North West, KwaZulu-Natal and even Gauteng becoming malaria zones by 2050," said Environmental and Tourism Minister Marthinus Van Schalkwyk on Thursday.

He also said the number of South Africans "at high risk" of contracting malaria would quadruple by 2020.

Malaria is transmitted to humans through the bite of an infected female anopheles mosquito and kills more than one million people worldwide annually, most of them children.

As global warming was expected to bring about changes in rain patterns in various regions, Van Schalkwyk said it would also exacerbate poverty.

"Climate change will intensify the worst effects of poverty through losses in biodiversity, agriculture, health, and almost every sector of society," said the minister.

"In less than 100 years, the research indicates that thousands of plant species may well be extinct, starting with a massive reduction in the distribution of fynbos and succulent Karoo biomes," said Van Schalkwyk.

Plant biodiversity is key to South Africa's flower-based export markets and eco-tourism in the Western and Northern Cape.

"Bird and mammal populations may be reduced with high rates of extinction in the central Highveld and even in the game-rich Lowveld areas - and negative knock-on effects for wildlife-based tourism," the minister added.