Antinuclear

Global warming brought extra hot summer to Australia

The Australian summer of 2012/13 was the hottest on record and the calendar year 2013 saw the highest average temperatures recorded in over 100 years of observations, University of Melbourne research fellow Dr Sophie Lewis, told the Australian Meteorological and Oceanographic Society‘s annual conference in Hobart today.

Modelling analysed by Lewis and Professor David Karoly points the finger at human influences on climate, particularly emissions of the greenhouse gas carbon dioxide.

Since records began in 1910, the average temperature in Australia has climbed by around 1°C, says Lewis.

This may not seem much, but Lewis says it is important: “With a degree change in average temperature we can get very large changes in the frequency and severity of climate extremes.”

In 2013 the average temperature, across the nation’s network of weather stations, was 1.2°C above the average for the 30 years between 1961 and 1990. Lewis and Karoly set out to find out why.

Parallel worlds

The researchers used “state-of-the art” climate models to run two different ‘experiments’.One experiment puts all the known influences on temperature into the models: radiation coming from the Sun, emissions from volcanic eruptions, and human influences such as carbon dioxide and aerosol emissions.

The second experiment puts in the same data for natural events, but no data for human influences…….

“This study really does show that the human influences – the global warming – made a very crucial difference to the extreme temperatures of 2013,” she concludes.http://www.abc.net.au/science/articles/2014/02/12/3943164.htm

February 17, 2014 - Posted by Christina Macpherson | Uncategorized