South Africa's government has set out an ambitious proposal to deal with climate change in the coming years, including slapping a possible carbon tax on carbon dioxide-spewing industries.

Saying the world faced "a global climate emergency," the environment ministry unveiled the strategy geared toward reducing greenhouse gases last week.

"The world faces a global climate emergency. It is now clear that only action by both developed and developing countries can prevent the climate crisis from deepening," environment minister Martinus Van Schalkwyk said in a statement.

The plan, which includes stringent energy efficiency measures, has been endorsed by the cabinet, though parliament must still approve it. Finance officials are investigating ways of implementing the tax.

The UN's Intergovernmental Panel on Climate Change (IPCC) has said evidence for warming was now "unequivocal" and that there was a more than 90-percent probability that humans were the cause for it.

Human-generated greenhouse gases rose by 70 percent between 1970 and 2004 from 28.7 to 49 billion tonnes per year in carbon dioxide (CO2) or its equivalent.

South Africa emitted about 446 million tonnes of CO2 in 2003 and forecasts growth to a maximum of 550 million tonnes a year by 2025, according to the environment ministry.

Van Schalkwyk said greenhouse gas emissions must stop growing at the latest by 2020 to 2025, stabilise for up to 10 years, and then decline in absolute terms.

"The aim is to limit global temperature increases to two degrees above pre-industrial levels," said Van Schalkwyk.

The plan has been welcomed by business associations and environmentalists as a major step towards galvanising rich industrialised nations into addressing climate change.

"The time is right for the country's private sector to show leadership by partnering with government to develop a solutions-driven national climate change mitigation and adaptation response," said Andre Fourie, chief executive of National Business Initiative, a group advocating sustainable development.

"The cost of inaction far outweighs the cost of mitigating the effects of climate change."

South Africa's reliance on coal to generate electricity makes it a major emitter of carbon dioxide and other greenhouse gases per capita.

State-owned power generator Eskom gets 90 percent of its electricity from coal-generated plants, according to the company. The supplier plans to develop three more coal-generated power stations in the next eight years.

The government's proposal includes shifting to cleaner-burning coal by introducing more stringent thermal efficiency and emissions standards for coal-fired power stations.

It also proposes providing incentives to renewable energy through a tariff system due to be finalised by the middle of next year.

Other aspects of the strategy include reducing transport emissions by imposing stringent fuel efficiency standards and promoting hybrid electric vehicles.

"Our emissions per capita are higher than many other developing countries. South Africa's emissions per capita are also high, due to our coal-based energy system," professor Harald Winkler from the University of Cape Town climate change department told AFP.

"Our analysis shows that putting a price on carbon has the single largest impact on emissions. By using the price signal, it sends signals to all actors in the economy, and can shift behaviour," said Winkler.