The biggest global challenge this century is climate control, chief scientific adviser to the British government Sir David King said yesterday at the South African media launch for an initiative known as 'Zero Carbon City' - a programme to raise awareness about the threat posed by global warming.

King is in South Africa to create awareness about global warming and to have bilateral discussions with the South African government.

He has called for talks at a global level to discuss climate control, saying that while the Kyoto protocol will not solve the problem of carbon emissions, it is a financial mechanism that can be tightened to force countries to act.

In the UK, government aims to reduce carbon dioxide emissions by some 60% by 2050.

In Montreal, later this year, the final touches will be added to the Kyoto protocol's carbon-trading policy.

Yet that is not enough; a G8 plus five conference is to take place in Scotland in July.

The meeting, Gleneagles, will be attended by the G8 as well as other rapidly developing countries: South Africa, China, India, Mexico and Brazil.

Part of the aim of the meeting is to share some of the UK's plans and successes, and King is hoping to influence government policy on carbon emissions at the meeting, in time for when countries such as South Africa join the Kyoto protocol in 2012.

He will be meeting with President Thabo Mbeki while in the country to discuss the Gleneagles meeting.

But as important as government policy is changing mindsets.

King believes that causing people to want to save energy, through a different vehicle or light bulbs for example, will ultimately change government policy.

Some 20 countries this year will take part in the 'Zero Carbon City' programme and, locally, four cities will host the North, South, East and West exhibition, which is aimed at young audiences such as schoolchildren.

Forming the backdrop to King's discussions in South Africa are issues around the international climate change challenge.

Predictions indicate that the globe will warm by between three degrees Celsius and four degrees Celsius if the amount of carbon dioxide released into the atmosphere doubles.

The consequences are disastrous.

In 2003, a white paper was compiled in the UK aiming to reduce emissions over the long term.

Targets for moving from fossil fuel to nonfossil fuel have been set and, already, renewable energy is feeding the power grid.

King elaborated on some of the consequences of not mitigating emissions.

“Ice acts like a canary for the effects of carbon dioxide emissions.”

Mount Kilimanjaro's supposedly permanent ice-cap is predicted to have completely melted in the next fifteen years.

Already, 85% of that cap is gone.

Some 8 000 km2 of China's permanent ice-caps are gone too, and the end of the century will see the end of that country's ice-caps.

Events such as these have not occurred since the last ice-age, 50-million years ago.

The last 'warm' period experienced by the planet was 10 000 years ago, when carbon dioxide particles were at 260 parts per million (ppm).

Currently, these are at 379 ppm, set to rise to 400 ppm in the next ten years.

For Southern Africa the weather implications are dire and include mass desertisation, a reduction in rainfall and a completely different weather pattern to the one we see now.