climateXchange

Clem Davis, retired after 33 years in the Bureau of Meteorology and currently a research fellow at ANU's Fenner School, gave a very interesting public lecture yesterday about his research on climate in Canberra and region.

He looked at data from observation sites at Canberra airport (1939-2009) and Queanbeyan (1871-2009) and found that:

1. Rainfall – there has been no significant trend in annual rainfall over the past century because there was a drier period in 1895-1915. However, there has been a drying trend in autumn over the past 10-15 years, and a drop-off in the number of low-rainfall days. Some days of high rainfall are contributing more to the rainfall total than a large number of low rainfall days.

2. Temperature – there has been a warming trend. The decade 2000-2009 was the warmest on record in the Canberra region across all seasons but especially in autumn and winter. Both maximum and minimum temperatures have increased over time. There has been a significant increase in hot days – in the period 1939-1973 there were 55 days with a maximum temperature of over 36.5 degrees C, but this increased to 97 days in the period 1974-2008!! There have also been more heat waves in the past decade than in any other decade in the record for the Canberra region.

So the evidence, particularly the temperature record, indicates that the climate in the Canberra region has indeed been changing.

Clem said that he plans to publish his research paper by the end of the year, and so it will be fascinating to find out more then.