Many Australians are taking their own steps to combat climate change.

Weekend Australian
Saturday 4/11/2006 Page: 38

More than 40,000 Australian households have installed a solar hot water system in the past 12 months, according to the Business Council for Sustainable Energy.

Environmentalist David Suzuki, who recently launched a tirade against Australia and the Federal Government's inaction on climate change, once stated that installing a solar hot water system was the single biggest change a householder could make to help the environment.

It would seem our future on this planet is moving up the agenda in many people's minds. It's a conclusion borne out by an AC Nielsen survey of 1500 Australians for the Australian Wind Energy Association last month, which found that 84 per cent believed Australia should take stronger action to reduce greenhouse gas pollution levels.

Furthermore, 71 per cent believed Australia should sign the Kyoto Protocol.

Many in the media and Government have chosen to liberally quote enviro-sceptic Bjorn Lomborg, who suggests climate change is a beat-up, rather than look at the evidence that something is happening quite rapidly.

The favoured argument of the sceptics seems to revolve around an acceptance of the world's increasing warmth coupled with the objection that no one really knows why temperatures are rising. Unfortunately, forces seem to be moving fairly rapidly to a point of no return.

For example, one major product of climate change will be rising sea levels caused (in part) by melting ice caps. Earlier this year, NASA and the German Aerospace Agency's joint satellite project uncovered the disturbing fact that the Antarctic is losing around 48 cubic kilometres of ice a year. If the loss continues at this rate, it will mean the rise in the sea level predicted for the next century may have been seriously understated.

For Australians, the reality of climate change is best illustrated by the current drought. Five years of below average rains across most of the nation coupled with some of the hottest years on record have increased our awareness and fear.

According to the CSIRO, the Earth has warmed, on average, by about 0.7°C since 1910 with nine of the 10 warmest years on record occurring in the past decade. There have been more heatwaves, fewer frosts, and a warming of the lower atmosphere and upper ocean. Australian temperatures have increased by almost 0.9°C over the past 100 years, which is slightly more than the global average.

The CSIRO says much of the warming since 1950 is due to human activities that have increased greenhouse gases. Atmospheric carbon dioxide levels have increased by 35 per cent from pre-industrial times. Ice core records indicate the current level is higher than at any other time in the past 420,000 years.

A recent climate change report in The Economist suggested that scientists are worried not just by the current level of warming but by its feedback loops - where warming sets off mechanisms that lead to more warming, spiralling out of control.

Among the major feedback loops outlined by The Economist were: Albedo - the tendency to reflect rather than absorb light. Ice floes tend to relect light, so as they melt, the Earth's albedo decreases and the Earth absorbs more energy, leading to a further increase in temperatures; Ocean absorption - as the seas warm they tend to absorb less carbon dioxide, because colder water absorbs more. The result: more warmth as more CO, is left in the atmosphere; Soil respiration - soil emits CO2 and warming may lead to a rise in microbial activity, causing emissions to rise faster than the increase in vegetation can absorb them.

CSIRO Research Fellow Dr Barrie Pittock argues that, even if the likelihood of such scenarios is put at only 20 to 30 per cent, it is still dangerous to do nothing or very little. The only way to prevent the worst-case scenario is to try to mitigate the effects of climate change now.

In an address last month to the Engineers Australia Water Forum in Brisbane, Pittock said scientists must "describe and warn" about the extent and likely effects of climate change, particularly in regard to water supply. Pittock, who is the retired leader of the CSIRO Climate Impacts Group, says measures designed to help communities cope with reduced water supply, such as water conservation and recycling, are urgent.

"However, unless the basic cause - globally increasing greenhouse gas emissions from the burning of fossil fuels - is dealt with, periods of water shortage will become more frequent and severe. The climate system will respond to the present increases in emissions over many decades to come. What we emit now will worsen the situation for decades into the future."