Bureau of Meteorology highlights influence of carbon emissions on warming trend as temperatures rise 1.2C above average

This article is more than 6 years old

This article is more than 6 years old

Australia experienced its hottest year on record in 2013, the Bureau of Meteorology has confirmed, with temperatures 1.2C above the long-term average.

The bureau said the new high, which breaks the record set in 2005 by 0.17C, “continues the trend” of steadily rising temperatures in Australia, which has seen the country warm by about 1C since 1950.

The year saw a number of individual records fall, including: The warmest summer and spring seasons ever recorded.

7 January was the hottest summer day ever recorded, at a national average maximum of 40.3C.

January’s heatwave set records for the hottest day, week and month on record, as well as a new record for the number of consecutive days the national average temperature exceeded 39C – seven days between 2 and 8 January.

The highest temperature recorded in 2013 was in Moomba in South Australia, where the mercury rose to 49.6C – the highest in Australia since 1998.

31 August was the warmest-ever winter day at 29.9C.

South Australia, Western Australia and the Northern Territory all broke their annual average temperature records, while all other states ranked in their top four years.

Overall, 2013 was 1.2C above the long-term average of 21.8C set between 1961 and 1990. The 10-year mean temperature for 2004 to 2013 was 0.5C above this average, with just one year in the past decade, 2011, cooler than average.

2013 annual mean temperatures compared to historical temperature records. Click here to enlarge. Photograph: Bureau of Meteorology

In its annual climate statement report, the bureau highlighted the influence of carbon emissions upon the warming trend, stating: “The Australian region warming is very similar to that seen at the global scale and the past year emphasises that the warming trend continues.

“As summarised in the recent Intergovernmental Panel on Climate Change Fifth Assessment Report, recent warming trends have been dominated by the influence of increasing greenhouse gases and the enhanced greenhouse effect.”

The bureau said sea surface temperatures were “unusually warm” in 2013, with preliminary data placing the year at 0.51C above the long-term average. Warming oceans pose a serious threat to the Great Barrier Reef, with coral bleaching contributing to the ecosystem losing half of its coral cover in the past 30 years.

Nationally, rainfall was 37mm below the long-term average in 2013, ranking it as the 52nd driest year on record. Rainfall was below average in Queensland, Victoria and parts of NSW and South Australia. Sydney and parts of Western Australia experienced higher rainfall than average.

Annual mean temperature anomalies for Australia (compared with 1961–1990 average). Click here to enlarge. Illustration: Bureau of Meteorology

The bureau noted a number of extreme weather events, including the heavy rain and flooding caused by ex-tropical cyclone Oswald in January, flooding in the Pilbara caused by tropical cyclone Rusty in February and bushfires in NSW, Tasmania and Victoria at various times during the year.

Dr David Jones, the manager of climate monitoring and prediction at the bureau, told Guardian Australia that the warming trend in Australia “is very clear”.

“We have had warm excursions before but if you look at the warm and cool anomalies, we’re now on a higher trend with higher benchmarks,” he said.

“We are now seeing temperatures unprecedented in our records. It was the warmest-ever year last year by some degree.”

Jones said the warmest trend was strongest in the interior of Australia, with the ocean helping coastal areas stay slightly cooler.

“In the last decade we’ve only seen one cooler-than-average year, so unless there’s a strong La Nina event it’s unlikely we’ll see cooler temperatures again in the near future,” he said.

“This year will probably be warmer than average. We’re not expecting it to be a record hot year again, but with a warming planet you can’t rule it out.”

David Karoly, a climate scientist at the University of Melbourne's school of earth sciences, said nine different climate models showed it was impossible for the warming record to occur without human influence.

"These indicate that greenhouse climate change vastly increased the odds of setting a new temperature record," he said. "In the model experiments it is not possible to reach such a temperature record due to natural climate variations alone.

"In simulations with no increases in greenhouse gases, none of the more than 13,000 model years analysed reach the record temperature observed in 2013. Conversely, in simulations for the period of 2006 to 2020 with natural variability and human influences, including increases in greenhouse gases, such records occur approximately once every ten years.

"Hence, this record could not occur due to natural variability alone and is only possible due to the combination of greenhouse climate change and natural variability on Australian average temperature."