This report provides a summary of observations of Australia’s climate and analysis of the factors that influence it.
It notes that the long-term warming trend has not changed, with each decade having been warmer than the previous decade since the 1950s. The warming trends observed around Australia are consistent with global-scale warming that has been measured during recent decades, despite 2010 and 2011 being the coolest years recorded in Australia since 2001. Global-average surface temperatures were the warmest on record in 2010 (slightly higher than 2005 and 1998). 2011 was the world’s 11th warmest year and the warmest year on record during a La Niña event. The world’s 13th warmest years on record have all occurred in the past 15 years.
There has been a general trend towards increased spring and summer monsoonal rainfall across Australia’s north during recent decades, and decreased late autumn and winter rainfall across southern Australia. The summary shows that the very strong La Niña event in 2010 followed by another in 2011 brought the highest two-year Australian-average rainfall total on record.
State of the Climate 2012 also highlights the increase in global sea level and notes sea-level rise around Australia since 1993 is greater than, or equal to, the global average. Our observations show that sea-surface temperatures around Australia have increased faster than the global average. The concentrations of long-lived greenhouse gases in the atmosphere reached a new high in 2011. Annual growth in global fossil-fuel CO2 emissions between 2009 and 2010 was 5.9 per cent, reversing a small decline of 1.2 per cent recorded between 2008 and 2009 during the global financial crisis.