David Heath
Tuesday, 16 March 2010 00:30
Science -
Climate
Page 1 of 3
Today the Australian Bureau of Meteorology and the CSIRO published a snapshot of the state of climate change in Australia.
The six-page
report paints a very consistent picture across a number of features of the Australian environment.
In simple terms, it is getting hotter and drier. Also, sea level is rising and the level of dissolved carbon dioxide in the oceans is rising rapidly. Furthermore, atmospheric carbon dioxide and methane levels are also rising.
The data very clearly shows that all of Australia has experienced some degree of warming in the past 50 years, the greatest increases (of as much as 0.4 deg C per decade) occur broadly in the one third of the country spanning much of South Australia, Northern Territory and southern Queensland. This gives a total increase of around 2 deg C over the 50 year period.
The Bureau also tracked the number of record hot days (the definition of 'record hot day' was not offered) and record cold days in each decade. There was a clear trend of increasing record hot days and decreasing record cold days.
A map of rainfall variation over the same 50-year period shows a structure that broadly mirrors the temperature variation map, with the observation that areas of the greatest increase in temperature also recorded increases in rainfall; those areas with mild temperature increase recorded sharp decreases in rainfall.
Amusingly, there was a narrowly-defined region of reduced rainfall sited directly over each of Melbourne, Sydney and South-East Queensland.
On the next page, we look at the effects on sea level and on the final page; we delve into the geological record to understand a mathematical model of long-term global trends and use that to predict the furure.
