CLIMATE CHANGE

Earthquakes, Tsunamis and Rising Tides –

is Gaia striking back?

Suggestions that rising sea levels along with more turbulent weather will destroy coastal landscapes and badly affect housing all along Australia’s coastline seem to be falling on deaf ears at present.

IN recent months we’ve had a major earthquake and tsunami (off Samoa) in the Pacific Ocean, followed just hours later by two earthquakes off Sumatra, Indonesia. Each caused massive damage and loss of life. Then, within a week, three more major earthquakes off Vanuatu. Meanwhile, two typhoons hit the Philippines and Vietnam bringing widespread flooding which caused more damage and loss of life. In September, red dust storms turned day into night across the east coast of Australia from Brisbane down to Canberra. Days later the same dust descended on New Zealand leaving a layer of red on everything in sight. Of course, dust storms like this have happened before – remember February 1983 in Melbourne? But have extreme weather events become more frequent in recent decades? Is Gaia really striking back ……..?

Effects on our Forests

And how is Orienteering likely to be affected? In Victoria, one Bush Orienteering event had to be relocated because the area originally chosen was badly affected in the February bushfires. And several other mapped areas have been “placed on hold” while they recover from the fires. But the affects of climate change on forested areas go deeper than merely burning and regrowth. A study in Canada on a onemillion square km area of forest found that the forest area has become a positive emitter of greenhouse gases. The increased incidence of forest fires in the area means that the forest now releases more greenhouse gases than it absorbs in photosynthesis. The forest area is no longer a carbon sink and has become a carbon emitter.

Early Settlers complained about the Weather

An interesting article describing the weather experienced by the first European settlers in Sydney more than 200 years ago puts climate change into perspective. According to the article published in the The Australian Meteorological and Oceanographic Journal, the first settlers in Australia might have been whingeing Poms, but in a reconstruction of the colony’s weather during the first four years to 1791, they had good reason to moan. The weather was terrible. The first two years were marked by cool temperatures and violent summer storms. Rain flooded trenches on building sites, roads were made impassable and lightning felled trees, killing livestock. By 1790, settlers were learning that Australia was a land of extremes. In the summers of 1790 and 1791 water supplies dried up and temperatures reached scorching highs of 41 degrees. Flying foxes and small birds reportedly fell from the trees and crops failed. “History has downplayed the environmental factors affecting the First Fleet settlers,” said Melbourne University climatologist David Karoly. “There was a perception that these were whingeing Poms and they weren’t used to it … but they had good reason to whinge about the hot summers because it was very hot and they were in a drought.” Contemporary reports are backed up by an analysis of the meticulous weather journal kept by Lieutenant William Dawes, a scientist who sailed on the First Fleet. Professor Karoly and his colleagues have used it, along with First Fleet logbooks and diaries, to plot the daily temperatures and barometric pressure between September 1788 and December 1791. The data was then compared with modern measurements taken from Sydney’s Observatory Hill weather station — located just 500 metres from the site where Dawes worked. “He gets the right seasonal variations, the right sort of maximum and minimum temperatures and very accurate pressure variations,” Professor Karoly said. Studying Australia’s climate variability before the 20th century was vital work, as it allowed present changes to climate trends to be viewed in a broader historical context, he added. “We want to understand natural weather and climate variations, so that we can set recent variations like the drought in Victoria and the Murray-Darling Basin into a longer-term context. Then we can work out whether the dry spell of the past 10 years is outside the current range of variability.”

Climate change dire for Coral Triangle

About 100 million people living on Australia’s doorstep could be forced to leave their homeland due to climate change this century, according to a report released earlier this year. The report, commissioned by the environment group WWF, found Australia will have a key role in avoiding ecological and humanitarian disaster in what it calls the Coral Triangle - the marine area including Indonesia, Malaysia, the Philippines, Papua New Guinea, the Solomon Islands and East Timor. It estimates that failure to take effective action on climate change will diminish the food supply drawn from the area’s coasts by up to 80 per cent. University of Queensland marine scientist Ove Hoegh-Guldberg, one of 20 scientists to work on the report, said under the worstcase scenario the ecology of the region would be destroyed by rises in ocean temperature, acidity and sea level. “Poverty increases, food security plummets, economies suffer and coastal people migrate increasingly to urban areas,” Professor Hoegh-Guldberg said. “Tens of millions of people are forced to move from rural and coastal settings due to loss of homes, food resources and income, putting pressure on regional cities and surrounding developed nations such as Australia and New Zealand.” Even under a best-case scenario, the report found the region will lose coral and have to deal with higher seas, more frequent storms, droughts and less food from coastal fisheries. The report calls for large cuts in greenhouse emissions and international financial support for the region’s environment.