The science is clear - it is man, and not nature, overloading the atmosphere with carbon. Nearly two thirds of the world's carbon emissions come from electricity generation and transport. But will a carbon-saturated atmosphere kill the planet? Or help it grow better?

As the scientists argue with the politicians Earth Report asks Australian film-maker Ian Henshke for his perspective on the big issue for this millennium: global warming.

Trouble ahead

Every year more than three billion tonnes of carbon are released into the air that the natural system cannot absorb. For over two decades scientists have been gathering evidence linking this carbon increase to accelerated global warming which they say will raise global temperatures, sea levels and change our weather patterns with devastating results on the Earth's environment and human life.

But it's the exact effect this increase in atmospheric carbon will have, and what we should do about it, that has been the centre of intense debate.

International summits aimed at reducing carbon emissions have fallen far short of the 50% cut scientists say is needed to begin solving the problem. In 1997 delegates at the Kyoto climate change conference only managed to agree a meagre 5% reduction on 1990 carbon emission levels by the year 2010.

Vested interests

Ironically, the main carbon polluting nations are the very countries least likely to encourage sizeable cuts in carbon emissions, which would have a very real impact on the profit margins of the most powerful oil, gas and coal multinationals. In the run up to Kyoto, fossil fuel lobbyists helped convince United States politicians that the Kyoto treaty would be bad for American businesses. It now seems clear that the Kyoto recommendations will not be implemented in the US - one of the worst greenhouse gas offenders.

Positive change

While the US fights over Kyoto, some developing nations are showing the rest of the world what can be done. In Costa Rica there is no debate over climate change. Its government is ploughing back a 5% 'carbon tax' into their forests and a new 'carbon trading' initiative, where farmers are paid to plant more trees, is helping to off-set carbon pollution from other countries.

Australia, which will need to plant millions of trees to even get close to its Kyoto committment, is grasping this opportunity and pushing tree planting at all levels of government and industry. One of the first major deals of this kind saw the oil giant BP Amoco plant 60,000 hectares of trees in Western Australia just to cover the million tonnes of carbon dioxide emitted each year from its refinery in Perth.

But while 'carbon credits' may be an easy way for countries to meet their targets, experts say that this trade only provides a breathing space, not a solution. Ultimately the pollution has to stop.

The future is now

If the world is convinced that global warming is man-made and not heaven sent, then we need to heed the warnings - the disappearing forests, extreme weather conditions and rising sea levels - and act now. But while the scientists and politicians continue to argue, Emission Impossible asks whether action will come too late for those nations who are, quite literally, going under?