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THE IMPACTS
OF GLOBAL WARMING

INERTIA: LEADERS FAILING TO ACT

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IS IN CRISIS


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The world is getting warmer
The world has been getting progressively warmer since the middle of the twentieth century. The pace of global warming has accelerated in the last twenty years and scientific projections are that this trend will continue.

In Australia, temperatures have risen by an average of 1°C in that period with 2005 being recorded as the hottest year since reliable temperature observations first became available in 1910. Data collected by the Bureau of Meteorology show that Australia’s annual mean temperature for 2005 was 1.09°C  above the standard 1961-90 average. The previous record of +0.84°C was set in 1998.

While these temperature increases may seem relatively small, the bureau equates them to the effect on a southern Australian town of being shifted northward by 100 kilometres.

Many of Australia’s hottest years on record (such as 1988, 1998 and 2002) had temperatures boosted by significant El Niño events. However, there was no El Niño in 2005, which makes that year’s temperature rise even more unusual and provides further evidence of the extent of climate change.

The warmer temperatures have created an increase in the frequency of heatwaves and a decrease in the numbers of frosts and cold days. Rainfall patterns have also changed. The north-west has seen an increase in rainfall over the last 50 years while much of eastern Australia and the far south-west have experienced a decline.

August 2006 was Australia’s driest month since rainfall records began in 1900, and the warmest August since 1950. According to the Bureau of Meteorology record low winter rainfalls covered an extensive area in the south-west of Western Australia, as well as parts of South Australia, Victoria and Tasmania. The central-west of New South Wales, areas around the South Australia-Victoria border and coastal parts of Western Australia had their driest weather on record in the six months to August 31.

Warmer than normal temperatures were not confined to Australia in 2005. According to the World Meteorological Organisation the global mean temperature was about 0.48°C above normal, putting 2005 among the four warmest years globally since records began. All of the ten warmest years have occurred within the last two decades.

Human activity contributes to global warming
There is compelling scientific evidence that human activity has been a contributing cause of most of the warming that has occurred over the last 50 years. This activity is blamed for the altered chemical composition of the atmosphere due to the buildup of greenhouse gases such as carbon dioxide, methane and nitrous oxide.

Since the beginning of the industrial revolution about 200 years ago, atmospheric concentrations of carbon dioxide have increased by nearly 30%, methane concentrations have more than doubled, and nitrous oxide concentrations have risen by about 15%. These increases have enhanced the heat-trapping capability of the Earth’s atmosphere (See panel at right).

Scientific research confirms that the increased emissions are caused by human activities such as agriculture and deforestation, and by people burning the Earth’s reserves of coal, oil and natural gas thus releasing billions of tonnes of CO2  into the atmosphere every year.

Despite scientific warnings and an increased global awareness of the problem there has been no progress in halting or reversing the impacts of climate change and the token efforts made to date have done nothing to slow the pace of global warming.

Even if governments had the will and the ability to resolve the problem of global warming tomorrow (which would require drastic and unanimous action by every country on Earth) the world will still suffer the impacts of the changes that have already occurred, and which are continuing to occur, for many decades (and probably centuries) to come.

The Intergovernmental Panel on Climate Change says that even if greenhouse emissions could be held at current levels, the world will still see a temperature increase of 2°C by 2100.

And if current trends continue, as it seems more likely they will, atmospheric CO2 concentrations this century will be double those of pre-industrial levels, with a corresponding rise in global temperatures by up to 5°C.

Visit the IPCC web site to read four key reports on the impacts of climate change: http://www.ipcc.ch

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