Predictions

The greatest dangers, which would result in global catastrophe, are posed by large scale and irreversible impacts such as:

* Greenland and Antarctic sheets melting. Unless emissions are reduced, warming in the next five decades could be large enough to trigger meltdown of the Greenand ice sheet;

* The Gulf Stream slowing or shutting down; and

* Massive releases of greenhouse gases from melting permafrost and dying forests.

There is a high risk of more extreme weather events such as heat waves and floods. These pose the most immediate threats.

Climate change will have severe impacts on a regional level. For example, in Europe, river flooding will increase over much of the continent, and in coastal areas the risk of flooding, erosion and wetland loss will increase substantially.

Natural systems, including glaciers, coral reefs, mangroves, arctic ecosystems, alpine ecosystems, boreal and tropical forests, prairie wetlands and native grasslands, will be threatened.

Climate change will increase existing risks of species extinction and biodiversity loss.

The greatest impacts will be on those least able to protect themselves from rising sea levels, disease increases and decreases in agricultural production in the developing countries of Africa and Asia.

At all scales of climate change, developing countries will suffer the most.

More people will be harmed than benefited, even for small amounts of warming.

These are the predictions of the International Panel on Climate Change (IPCC). In the IPCC's latest report, the third assessment released in 2001, the anticipated increase in average global temperature over the next 100 years is between 1.4 and 5.8 degrees celcius.

This is increasing from 1 - 3.5 degrees celcius according to the panel's second assessment, which was released in 1995.

Not only is climate change happening faster than previously predicted, but it may happen even faster than the latest predictions.

Dying forests, more fires and warming soils could release huge additional amounts of carbon - substantially accelerating warming.

The IPCC's third assessment states that "The projected rate of warming is much larger than the observed changes during the 20th century and is very likely without precedent during the last 10,000 years." The difference between the present average global temperature and the last ice age was only five degrees celsius.

Never before has humanity had to grapple with such an immense environmental crisis. If we do not take action to stop global warming immediately, the damage will be irreversible.