Friday, September 20, 2013

Early start to Australian bushfires, record temperatures


Just a few days after the Federal election NSW experienced a surprisingly early start to the bushfire season with fires on Sydney's outskirts giving us a taste of things to come. Queensland is also facing severe fire danger with the early onset of high temperatures.

The Australian Bureau of Meteorology also issued a special climate statement saying that the last 12 months is Australia’s hottest 12 month period on record, and it's second warmest winter on record for maximum temperatures.

The Bushfire CRC has already advised we are facing above normal potential for the 2013-2014 fire season in much of southern and western Australia:

"due to abundant grass growth across inland Australia, due to above average rainfall since May 2013. These conditions, coupled with above average temperatures across the country since January 2013, have resulted in a build up of fuel in grasslands. These higher temperatures have also seen forests begin to dry out."


Warmest 12 month record for Australia says BOM

The early start to the bushfire season was followed on September 13 by a Special Climate Statement (PDF) from the Australian Bureau of Meteorology (BOM).

"The last week of August 2013 and the first half of September have seen record high temperatures for this time of year, affecting large parts of Australia (Figure 1 and 2). On the last day of winter, Australia recorded an average maximum temperature of 29.92̊C. A new daily record was also set for winter exceeding the previous record high by 0.19 ̊C (29.73C set on 23 August 1995). This was followed by an early arrival of very warm conditions with 31.45 ºC recorded on 1 September for Australia - averaged maxim a, setting a new record for the earliest 31 ºC day by 15 days (previously 31.68 ºC recorded on 16 September 1981)."

Over the last 12 months Australia has experienced it's hottest summer day on record (7 January), warmest winter day on record (31 August), warmest month on record (january), warmest summer on record, warmest January to August period on record, and warmest 12 month period on record.


Recent Records broken include:

  • Sydney had its warmest winter on record for maximum and minimum temperatures and
    broke its early season record with 31.6ºC recorded on 10 September (previous was 31.3ºC
    26 August 1995 and 8 September 1953).
  • Canberra had its earliest spring day of 25 ̊C or above on 2 September, beating the previous record by 11 days (13 September 2008)
  • Several locations set or equalled records for the earliest day above 35 °C or other
    significant thresholds
  • A total of 20 maximum and 12 minimum early season temperature records have been broken or equalled for the Australian Climate Observation Reference Network – Surface Air Temperature
  • Alice Springs experienced 16 consecutive days above 30 °C, the longest such run ending on or before 30 September (previous was 12 days in 2000). Equivalent September records have
    also been broken at locations such as Ouyen (9 consecutive days above 25 °C) and Tarcoola (3 consecutive days above 35 °C).
  • Last 12 months is Australia’s hottest 12 - month period on record with an anomaly of +1.11 °C. This is a record high temperature for any 12 - month period (i.e., all January to December, February to January, etc.), with the year-to-date temperature with an anomaly of +1.13 °C (January to August) breaking the previous record (+1.05 °C in 2005)
  • Australia recorded its second warmest winter on record for maximum temperatures (+1.42 °C).

Mean, maximum and minimum temperatures for the last 12 month period September 2012 to August 2013. Image: Courtesy BOM

Last January we experienced an angry summer with intense heatwave conditions exacerbating bushfires and causing heat stress. Human caused Climate change is clearly implicated. We tend to think of cyclones, fires and floods for their destructive capacity and greatest threat to life, but the statistics show that Extreme heat and heat stress trumps all extreme weather events in Australia for it's mortality impact.

While Australia's new Federal Government are intent on dismantling carbon pricing and clean energy schemes instituted by the previous minority Labor Government, both the Global and Australian climate are already changing for the worse which will inflict greater social costs and damages.

Warmer winters are also likely to affect winter chill requirements for orchard fruit and nuts.

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