What I am struggling to understand is why were we presented with graphs of days over 35 degrees for Bathurst as part of this argument. Most of those days would have occurred in January and February and provide no useful insight into why there was a massive bushfire in the Blue Mountains in October.

If Jennifer wanted to delve into the climate data, she could have done something more interesting like look at average maximum temperatures for September over the period. Had she done so, she would have seen that average maximum temperatures for September at Bathurst has increase significantly since 1966 (the first data in the BOM spreadsheet) by 0.7 degrees per decade. So over that 50 year period, September temperatures are on average 3.5 degrees warmer than in the 1960s. Perhaps this might be playing a role in the unprecedented bushfire in the Blue Mountains in October 2013?

Days over 35 at Bathurst certainly didn’t, because the last one of those was on January 18th 2013.

Even leaving that aside, the argument made makes limited sense. If the climate is warming, surely there is even more need to improve bushfire preparedness in places like the Blue Mountains and elsewhere?

http://www.bom.gov.au/climate/change/

Australia’s warmest 12-month period on record, again
Australia’s warmest September on record
Australia’s record for warmest 12-month period has been broken for a second consecutive month. This continues a remarkable sequence of warmer-than-average months for Australia since August 2012.
September 2013 was easily Australia’s warmest September on record. The national average temperature for September was +2.75 °C above the long-term (1961–1990) average, which also sets a record for Australia’s largest positive anomaly for any monthly mean temperature. The previous record of +2.66 °C was set in April 2005.
The mean temperature for Australia, averaged over the 12 months from October 2012 to September 2013, was 1.25 °C above the long-term average. This was also 0.17 °C warmer than any 12-month period prior to 2013.
The previous record, set over September 2012 to August 2013, was +1.11 °C above the long-term average, and the record preceding the current warm spell was +1.08 °C, set between February 2005 and January 2006.
Temperatures for the calendar year to date (January to September) have also been the warmest on record, at 1.31 °C above the long-term average, well above the figure set for January to September 2005 (+1.07 °C). 2005 currently holds the record for Australia’s warmest calendar year.
The past 18 months have been characterised by widespread heat across Australia. The mean temperature has been above average over the entire continent.

Garry in Liffey AGW, oh sorry I mean Climate Change! Why was that changed? On your figures it is still AGW so why the change? Mate you must think that after the Y2K bug Joe Public will swallow anything. The trouble is mate that after 2000 came and went people were a little more circumspect.
Personally the BOM should have funding and management reduced by 10% this year. Then let them know if it gets any hotter they will suffer again see what happens then.

JBowyer,

The reason that 2000 came and went without major problems concerning Y2K was that a lot of people put a lot of time and effort into rectifying the problem before it arose.

Or has that minor detail escaped you?

There are so many different ways the data can be dissected and plotted. I started with hottest days because the technical literature indicates that these are most important.

It would be nice if 'Agronomist' and others could, in the first instance, acknowledge that there has been no increase in hot days at Bathurst over the last years… contrary to perceptions.

I do intend to do a careful analysis of the Bathurst data looking to see if this September and October are particularly unusual in terms of maximum daily temperatures and mean maximum temperatures.

But I've first had a look at the minimum temp data… in particular because I received many emails explaining that Andy Pitman says that we have just had a very mild winter.

So how mild was the winter at Bathurst...
http://www.mythandthemurray.org/no-increase-in-warm-nights-or-mild-winters-at-bathurst/ ?

Garry in Liffey - it's all well and good to declare hottest this and record that when you don't actually reveal your data source.
For example, in the BOM Hottest September Media Release they state what sites were used in creating the report.
So I checked on the first one on the list - Halls Creek. They claim 40.2C this September was a new record for Halls Creek.
Yet if you go to the BoM data online site and call up Halls Creek you will find that there is a closed station, Old Halls Creek, and if you check that record you will find that the highest temperature recorded in that data base was 12th September 1917 with a reading of 40.2C

This is the problem we face with this current BoM. They have closed down many of the sites that have long periods of consistent data, Casino, Central Lismore, to name a couple, and have removed the data from the national data base. What we have today in the ACORN data set is an homogenized, adjusted temperature record with the predominant adjustments to a warmer present and a cooler past.

Jennifer's analysis of Bathurst temperatures is a perfectly adequate method of seeing if a warming planet is in part responsible for the intensity of the recent fires. We know that globally the planet has not warmed for the past 15 years but maybe the area around the bush fire may be warming unnaturally. Yes the maximum temperatures in Bathurst from the 60s to the 2002 have risen slightly but over the past 10 years it has in fact cooled slightly.

MacQuarie University created a paper for the Senate Standing Committee on Environment & Communications Inquiry into Recent Trends in and Preparedness for Extreme Weather Events.

They concluded that:

Research into the economic impacts from natural disasters now spans many parts of the world. No study has yet been able to detect an anthropogenic climate change influence. Anyone asserting the contrary now has a mountain of peer-reviewed literature to climb over.

http://www.riskfrontiers.com/pdf/Senate%20Enquiry_Risk%20Frontiers_website.pdf