3 Atmosphere | 2 Climate
State of the Environment 2011 Committee. Australia state of the environment 2011.
Independent report to the Australian Government Minister for Sustainability, Environment, Water, Population and Communities.
Canberra: DSEWPaC, 2011.
At a glance
From 1970 to 2010, Australia’s mean daily temperature rose in almost all parts of the country. Although total annual rainfall declined over much of eastern Australia and south-west Western Australia, increases were observed in central and northern areas of Western Australia and in the north-western part of the Northern Territory. The 13-year period from April 1997 to March 2010 was characterised by severe rainfall deficiencies that covered much of south-western and south-eastern Australia and south-eastern Queensland. For many places, the severity and duration of drought were unprecedented, with profound environmental, social and economic implications. Then, in the 12 months from March 2010, large parts of the continent experienced above-average rainfall, associated with an extremely strong La Niña event. Most notably, eastern Australia received widespread record-breaking rains, with associated loss of life and massive damage to agriculture, homes and infrastructure.
The summer of 2010–11 will be remembered as one of extremes and variability, with Perth experiencing a record run of temperatures above 30 °C. By contrast, when averaged across the continent, summer maximum temperatures were 0.72 °C below the norm, making them the lowest since 2001. Despite this, the decade ending in 2010 was the hottest 10-year period on record for Australia, with the average land surface temperature 0.52 °C above the 30-year average from 1961 to 1990.
References to Australia’s variable climate abound in both academic literature and the arts, with Dorothea Mackellar’s description of her love for a ‘sunburnt country, a land …of drought and flooding rains …’ springing readily to mind. Marked variability in temperature and rainfall, together with frequent but irregular occurrences of extreme weather events, has long been recognised as a key characteristic of climate in most parts of our continent. On more than one occasion, confusion of short-term runs of favourable climate with long-term norms led farmers to push into areas where their agricultural systems proved to be unsustainable. As we move into the second decade of the 21st century, we are increasingly recognising signs that our already variable climate is changing.14