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This week: Climate change in Australia
Any doubts about climate change and global warming were neatly excised from the Rotary Club of Balwyn’s consciousness by a global climate expert, Professor Dr. David Karoly of Melbourne University.
One of the world’s notable climatologists, he advises the Australian Government on climate research and teaches in the school of earth sciences at Melbourne University. A B.Sc from Monash and a Ph.D from Reading in the UK, he is a former head of mathematic sciences at Monash and has held the Williams chair in meteorology at the University of Oklahoma.
Climate change and global warming were a matter of statistics and observation but the alarming thing about the figures being gathered was that the rate of that change is accelerating faster than at any time so far measured, he said.
Reports chronicling the changes to the climate had been assembled by the International Panel on Climate Change, the last in 2007. The report was the size of three large `yellow pages’ directories which was thought to be indigestible to many who may need the information contained. So a summary was arranged.
``This used shorter words and was designed for policy makers,’’ said Dr. Karoly revealing a dry sense of humour when alluding to his role in advising the Australian Government.
He began by dismantling arguments raised by climate sceptics such as Andrew Bolt in the Herald-Sun using observations and graphs of climate readings from the last 150 years or so. In the past 120,000 year cycle, there had been change but not at today’s faster rate. The last ice age was 15,000 years ago and it began warming. Without the atmosphere earth would be uninhabitable with a temperature of negative 15degC compared with today’s average of plus 15degC.
``There are occasional aberrations but the trend remains,’’ he said adding ``there are moments of observations of ice increasing in parts of the Northern Hemisphere. But there were periods 200 million years ago when Antarctica was green and the temperature was higher.
``But there is now ice core evidence of climate warming around the world, particularly in winter. Warming might be expected during the day if it was to come from the sun but this is occurring also at night,’’ he said suggesting the greenhouse gases produced by man were holding in the heat.
``Most of the warming is due to the influence of greenhouse gases and the activities of man are a major cause of these,’’ he said.
Referring to the south of Australia, he pointed out the gradual drying of the areas of Victoria, South Australia and the southern parts of Western Australia. The level of rainfall was falling in the south and rising in the north.
``However, winters are getting warmer in the south so there is an up side,’’ he said ``but higher temperatures mean the atmosphere can hold more water and heavier loads of water can lead to more intense storms such as the one Melbourne experienced earlier this year.
``The increased amount of CO2 in the air meant more would be absorbed by the oceans and this would make them more acidic. And melting ice could lead to rising ocean levels.
``The upside for more CO2 and warming temperatures was good for plants. Higher CO2 levels 4500 years ago benefited plants,’’ he said.
``The problem was that changes were now going faster than predicted. Even the graphs were showing an actual increase in temperature that was seen once as being at the outer limits of possibility. The one degree centigrade that occurred over the past century could now be two degrees or more,’’ he said.
``One aspect of the problem as seen by the International Panel on Greenhouse Gases was that three countries – Australia, Canada and the United States – were producing far more greenhouse gases per person than other countries. The average in the world was five tonnes per person contrasting with perhaps three in India and 25 tonnes in Australia, Canada and the US.
``With more solar energy input than the rest of the world, Australia was well placed to reduce its greenhouse gases. However, it would require drastic changes to reduce Australia’s greenhouse gas emission. Victoria was the world’s worst at greenhouse gas output due to the burning of coal to produce electricity. The coal should be used as fertiliser,’’ he advised.
Drastic change to the CO2 output was needed around the world and a carbon trading scheme was needed to make it a commercial reality.
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