Here I sit on another insufferably hot night in Adelaide in a home with single A/C unit in one room. That room currently has my sleeping children as the bedrooms are too hot for sleeping. It also has the TV, leaving me at something of a loose end as I solo-parent on this Sunday evening.

In this last fortnight of stinking heat my wife and I have been trying to recall if it were this hot when we were kids. Summer used to feel leisurely. This year, especially with kids, it feels tiresome and occasionally hazardous. Days exceeding 40 deg C are a memory of something special from when I was young. Now they are commonplace. Or so it seems. Are we remembering correctly? How does our sense of times past compare with the data?

Our local weather station has reliable temperature data since 1977 (I was born in 1978, my wife in 1977, so that’s perfect). I have just grabbed the Tmax data to look at days ≥ 40° C by calendar year. Here they are:

Tmax Adelaide
Daily maxima exceeding 40 deg C for Kent Town, Adelaide. Data from BoM

So it seems memory serves pretty well actually. In the years of our respective births, not a single day met or exceeded the 40° C threshold. Similarly in our childhood years, on three further occasions the threshold was not met (1984, 1992, 1995), and on five of the years before I turned 18 the threshold was only met once.

My son, born 2008, is in his 7th year on earth. The tallies for his years are 5, 12, 5, 2, 4, 7, 7* (we still have February and December of this year to come). It would appear he has been born into a different climate.

Of course it’s the hot nights that really break us. Here, using ≥26 deg C minima, we see a similar story.

Tmin Adelaide
So far, so good. Our memories are spot on. It is worth noting the hump between 1980 and 1983. We were alive, but not old enough to remember much, and these were hot years. The inter-decadal climate variability that Australia is known for is on show. There were famously bad bushfires in Adelaide in this period (colloquially known as Ash Wednesday).  Had I chosen a shorter data set, say from my first year of school (1984) my result would have been a much greater upward trend. So it’s clear memory and folk knowledge ought not be given priority over data!!!

One last check is in order for a stinking Sunday night, and that’s the El Nino effect. Those wonderful people at the Australian Bureau of Meteorology give me a season-by-season summary of the events.  This is concerning. During 2006-07 and 2009-10, where conditions were as hot and more so than the 1980-1983 period, Australia was strongly affected by weak El Nino seasons. By contrast in 1982-1983  Australia was very strongly affected by a very strong El Nino.

In the short span of my life, it would appear I have lived through an altering of climate. It really is getting hotter down under, and it would seem safe to expect more and worse in future for quite some time to come.

We need to adapt, and we need to implement big mitigation solutions, fast, to make the future something we can reasonably adapt to.

Like what you see here? Please subscribe to the blog, Like Decarbonise SA on Facebook and follow @BenThinkClimate on Twitter. Read more about the potential for nuclear power in Australia at Zero Carbon Options

For anyone wishing to replicate this for their location, here are some steps to follow:

  1. Visit http://www.bom.gov.au/climate/data/ . Choose temperature data
  2. Locate your relevant weather station
  3. Hit “Get Data” button down the bottom. New window will open
  4. In the new window click the link “All years of data” in the top right. You will get a downloaded .csv file. Open it.
  5. Select all the data and Sort by Maximum Temperature, Largest to Smallest
  6. Highlight the records above your threshold. Copy to a new tab
  7. Sort again, this time by Year, Smallest to Largest
  8. Create a list of calendar years. and take a count (manually, or using the COUNT formula) of records for each year, inputting the result in your new list.
  9. Create a chart and share the results!

9 comments

  1. Yes, I’ve been thinking the same thing and meaning to check my memory … thanks Ben!

    Suzanne and I moved to Adelaide in 1977 and didn’t have air conditioning until fairly recently (about 10 years) … when we bought the aircon we figured we were just getting old and needing to actually sleep during heat waves 🙂

  2. It would be interesting to see similar graphs for each of the capitals, with short notes such as the ones regarding el nino events, where these are relevant – probably not so, for Perth and Darwin, but what would I know?

    The complete set would tend to bring home to 90% of Australians the facts of their recollections. Whether they are as extreme as the current Adelaide/Melbourne experience or somewhat milder remains to be seen, but I have little doubt about the direction of the trend over the past 30 – 50 years.

    Think of the exercise not as ammunition, but as memory calibration. Good, bad or otherwise, the results would illustrate the fallibility of long-term memory.

    Some years back I was invoIved in a similar exercise with Hunter River rainfalls and river flows circa 1905 to 2005, in order to judge the effects of different pumping regimes on a 73 Gl annual licence. The upshot was to triple the size of the pumping station and take more during freshes. We now leave twice as much in the river for minimum environmental flows. It was expensive, but everybody is a winner. This includes the power stations, which now receive less saline water and have recouped their capital cost by reduction in desalination cost.

    As with your discussion, the analysis used data strings based on actual measurements, rather than statistical tools based on assumptions about average storms and the hydraulic flow characteristics of a river. I was going to use conventional civil engineering estimating tools to model the catchment and estimate rainfall and runoff – I was dead wrong, because I would not have convinced anybody, myself included, that the results could be trusted.

    Thanks for a good yarn. Looking forward to another 2 degrees in the next 35 years?

  3. An amazing bit of good luck was the bicycle race The Tour Down Under falling between hot weeks. In some areas the week before it got to 46C and in the last week to 45C. A bit warm for riding a pushie up Willunga Hill. During the TDU maximums were 25-32C so they didn’t have to cancel. Next year or the following year their luck may not hold. Ironically Santos the major sponsor of the event is the key producer of gas that provides a neat 50% of the state’s electricity… see the recent AEMO report on SA fuel options. If air conditioning gets too expensive you know who to blame.

    Without checking I believe Hobart had just one 40C day in the 150 years or so prior to 2010. Now it’s every year. A GW denier said it must have happened numerous times in the past. Maybe that was the same years they grew grapes in Greenland or whatever their preferred fantasy is.

  4. Going to pick on you slightly and say get a better A/C. Something modern, efficient, automation friendly.
    Then add a solar system. Peak demand and high temperature go hand in hand, with only a slight reduction in generation due to heatwave conditions.
    While thing have changed, the worst thing we can do is fail to adapt. I agree with you that nuclear is a good longer term solution (peak uranium is unsettling), but there are existing viable solutions which are carbon neutral.

  5. It’s been the same up here Mr Heard, spare mattress and kids in the lounge room with our single old A/C cranked… Undoing all the day’s fine CO2 mitigation achieved by our 3kW of PV and solar tube hot water…

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