13 February 2017

Record-busting heat in eastern Australia as climate warming goes extreme


Projected temperatures across Australia for Sunday 5 February 2017
12 FEBRUARY UPDATE:
  • The average maximum temperature across the state of New South Wales broke the record with 42.4C on Friday 10 February, which was then smashed the following day with 44.02C on Saturday 11 February. 
  • On Saturday 11 February, many NSW towns set new benchmarks: Walgett (47.9 C), Taree (45.7C), Port Macquarie (46.5C) and Kempsey (46.4C).
  • All time records were also set in Queensland, including Toowoomba (40.8C), Gatton (45.7), Oakey (42.8C) and Kingaroy (41.6C).
  • In Victoria, Mildura became the first location in the state to record consecutive days above 46C, on 9-10 February.
6 FEBRUARY UPDATE: The Queensland town of Moree has recorded 41 days in a row of temperatures above 35C, absolutely smashing the previous record from 1981-82 of  17 days. 

First posted 5 February 2017

2016 was by far the hottest year in the observation record, with the global average surface temperature 1.24 degrees Celsius (°C) warmer that the late nineteenth century, according to NASA data. This broke the record set just the previous year of 1.12°C, which in turn broke the previous mark set in 2014 of 1.01°C.

 Although the El Nino conditions of 2015-2016 had some influence (perhaps 0.2°C) it is clear that the warming trend is 1°C or more.

And now Ben Domensino of Weatherzone reports that the month of February is about to put eastern Australia's record-breaking hot January to shame, with a historic spell of hot days and nights gripping parts of central Australia, southern Queensland and northern New South Wales during the first half of February:
The southwest Queensland town of Birdsville is forecast to reach 45-48 degrees from now until Thursday and could extend this run to 10 days by next weekend. This spell would smash the existing record of six consecutive days over 45 degrees from 2014 and 2004. Overnight minimums during this time should remain above 30 degrees, beating the 2012 record of six in a row. Birdsville's hottest day on record was 49.5 degrees on 24th January 1972.

Thargomindah's run of days above 44 degrees could reach 10 by Friday next week, including a few days at 46 degrees. The previous record run of days above 44 in the last 138 years was seven, in 2004.

Walgett in northern New South Wales will be a few degrees 'cooler' than its northern neighbours, reaching 41-45 degrees for the next week. This would take their run of days over 40 degrees to 12 by Thursday and it should to reach 15 next weekend.

Bourke has exceeded 40 degrees for the last six days in a row and will extend this tally to 16 by next weekend. There is a good chance the 121 year old record of 22 days above 40 degrees will be beaten by the middle of this month.

South Australia's Moomba is forecast to reach 46 degrees for six days straight, from this Saturday to Thursday next week. This will be an unprecedented run of hot days for the town, which has data available back to 1972.
These are extraordinary events in an extraordinary year of climate-warming impacts. In the Arctic, the volume of sea-ice during the northern summer of 2016 dipped to be 72% below the level 30 years ago. Mark C. Serreze, director of the US National Snow and Ice Data Center says: “What has happened over the last year (in the Arctic) goes beyond even the extreme.”
Global average temperature 1880-2016 (NASA)
 And now a new report from another US agency, the National Oceanic and Atmospheric Administration, has recommended a revised worst-case sea-level rise rise scenario of 2.5 metres by 2100, half a metre higher than their previous assessment. The upper limit for sea-level rise now set at 5.5 metres by 2150 and 9.7 metres by 2200. It says sea level science has “advanced significantly over the last few years, especially (for) land-based ice sheets in Greenland and Antarctica under global warming, and the correspondingly larger range of possible 21st century rise in sea level than previously thought”.

In Greenland, for example, the ice sheet is melting 600 per cent faster than predicted.

 And in Antarctica, our recent report shows that  no further acceleration in climate change is necessary to trigger the collapse of the West Antarctic Ice Sheet on decadal time scales. This alone means Antarctica has the potential to contribute more than a metre of sea-level rise by 2100, and a large fraction of West Antarctic basin ice could be gone within two centuries, causing a 3–5 metre sea level rise.

Extreme heat. Extreme melting. Extreme sea level rises in train. This is not the story of future climate change, it is the story of now.