Sydney’s driest June in a decade is a wake-up call to initiate climate-smart actions

Australia's department of environment removes references to climate change from its official advice on extreme climate

 
By Kiran Pandey
Last Updated: Monday 17 August 2015

Sydney experienced a record-smashing 14-day heatwave in May this year

For Australia, 2013 is indelibly marked in its memory for the heat records it set. This year, too, with Sydney witnessing the driest first half of the year and driest June in the decade, it is time the government acknowledges the climate risks it faces. This is a wake-up call for climate-smart policy and planning.

While the Australian government has been accused of significantly watering down its official advice on extreme weather after removing mention of links between climate change and events such as bushfires and heat waves, June 2014 is set to be the city’s third warmest in 155 years of records, based on the average of minimum and maximum temperatures.

Doctored document?

The document on the website of Department of Environment, Australia, explained and provided information on how climate change is influencing dangerous weather. But it has now removed the statements that explicitly link climate change with extreme events like heat waves

Previous version : “There is a growing and robust body of evidence that climate change will increase the frequency and intensity of extreme weather events.

The Edited Version : The frequency and intensity of extreme weather events is “changing” and that “some studies” show a link to climate change, but stresses that it is “difficult to isolate the role of climate change in any given event”.

June 2014 is now recorded as Sydney’s driest June in a decade with 68 mm of rain which is just 50 per cent of the long-run average of 132.4 mm. The city has also seen the driest first half of the year in a decade, according to Brett Dutschke, senior Australian meteorologist.

image

Heat waves

June was also marked by two “warmwaves” – stretches of at least three days in a row of maximums in the warmest 10 per cent of records for that date – following up a record-smashing 14-day heatwave set by Sydney in May, according to the University of NSW's Scorcher website, which tracks heatwaves anywhere in Australia in real time and is updated daily. It is an initiative of Sarah Perkins at the Australian Research Council's Centre of Excellence for Climate System Science at the University of NSW, and is designed to help the community better understand current and earlier heatwaves.

What are the reasons for the unusually warm and dry June 2014?

  • Dominant high-pressure systems that have made cold fornts less frequest” then they typically should be.
  • Warmer-than-average sea-surface temperatures around most of Australia.

 

2013 in Australia
 
  • Australia’s warmest summer (+1.11°C for 2012–13) and spring (+1.57°C) on record
  • Australia’s warmest January (+1.76°C) and September (+2.75°C) on record; September’s temperature anomaly was also the largest for any month since at least 1910
  • Australia’s hottest summer day on record ( January 7)
  • Australia’s warmest winter day on record (August 31)
Source: Annual Climate Statement 2, 2013

 

With the National Water Account Summary  released by The Bureau of Meteorology showing that total water use increased by 35 per cent in 2012-13 compared to the previous 2011-12, the warmer periods ought to be considered by the Australian government while planning for future.

The IPCC assessment, released in March 2014  has a word of caution for the continent nation. It has stated there is a “medium to high confidence” that extreme weather events are “projected to increase in many locations” in Australia (see box).

IPCC's note of caution
 
  • The regional climate is changing (very high confidence). The region continues to demonstrate long term trends toward higher surface air and sea-surface temperatures, more hot extremes and fewer cold extremes, and changed rainfall patterns. Over the past 50 years, increasing greenhouse gas concentrations have contributed to rising average temperature in Australia (high confidence)
  • Warming is projected to continue through the 21st century (virtually certain) along with other changes in climate
  • Annual average rainfall is expected to decrease in south-western Australia (high confidence) and elsewhere in most of far southern Australia and the north-east South Island

Source: IPCC WGII AR5 Chapter 25



The State of Climate Report 2014, Australia, also shows that over the past 15 years, the frequency of very warm months has increased five-fold and the frequency of very cool months has declined by around a third, compared to 1951–1980.

Warming facts

  • Australia’s mean surface air temperature has warmed by 0.9°C since 1910.
  • Seven of the 10 warmest years on record have occurred since 1998.
  • Over the past 15 years, the frequency of very warm months has increased five-fold and the frequency of very cool months has declined by around a third, compared to 1951–1980.
  • Sea-surface temperatures in the Australian region have warmed by 0.9°C since 1900
  • A declining trend in winter rainfall persists in southwest Australia
  • Autumn and early winter rainfall has mostly been below average in the southeast since 1990



Driven by rising temperatures and reduced cool season rainfall, there is a need for effective integrated responses encompassing management of supply, recycling, water conservation and increased efficiency across all states and territories as already stated by latest IPCC report on climate change.

Natural climatic variability is very high in the region, especially for rainfall and over Australia, with the El Nino-Southern Oscillation (ENSO) being the most important driver. According to a news report in Reuters, the Australian Bureau of Meteorology  indicates that El Nino is likely to develop by spring 2014.

Isn’t now the right time for Australia to start a climate-smart sustainability plan?

 


Report: State of the Climate 2014

Report: Heatwaves: Hotter, longer more often

Report: Climate change adaptation and the Australian urban water industry

Report: Climate Change 2013: The Physical Science Basis

Report: Climate Change 2009: faster change and more serious risks

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