2020-03-01_Australian_Geographic

I

N AUSTRALIA, 2019 was offi cially the hottest and driest year

since records began (Figure 2) with 18 December offi cially the

hottest day ever with a mean national temperature of 41.9oC.

The country as a whole was 1.52oC above the Bureau of Meteorology’s

(BOM) 1961–1990 average. Global temperatures for 2019 were

1.1oC above the 1961–1990 average, making it the second-

warmest year globally since 1880.

Long-term climate trends show clear warming (Figure 1) with a

resulting increase in the duration and intensity of the annual bushfi re

season. Australia has warmed by 1.4oC since 1910 with most of that

increase taking eff ect from 1950 onwards. Nine of our 10 warmest

years have occurred since 2005 including each year since 2013.

The national total rainfall for 2019 was 40 per cent below

average (Figure 3), making it the driest year since records began,

although some northern regions saw above average rain in the early

months of 2019, leading to fl ooding in parts of Queensland. Low

humidity has increased fuel loads and made previously cool, moist

and fi re-resistant temperate rainforest gullies more susceptible to

fi re than ever before.

Australia has seen long periods of either wet or dry weather

throughout recorded meteorological history and current trends are

in part attributable to natural variability, but there are high levels of

scientifi c confi dence in the role played by human-induced climate

change in the weather patterns that led to the optimum conditions

for the 2019–2020 catastrophic bushfi re season. Longer and more

intense fi re seasons are reducing the eff ectiveness of existing fi re

management strategies.

48 Australian Geographic

1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020

+1.5

+1.0

+0.5

-0.5

• 0.0
  (30-year average)

-1.0

°C

1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020

COOLER

THAN AVERAGE

Australia in 2019

1.52°C above the

30-year average.

Global warming trend

Global average temperatures

have been above the 30 year

average since 1986.

Warming trend is more

pronounced in Australia

In 13 of the last 20 years,

Australia's temperature

increases have been larger

than global increases.

Mean Temperature Anomaly, 1920–2019

Based on BOM 30-year temperature averages (1961–1990)

WARMER

THAN AVERAGE

Source: BoM

21.8

°

C 13.97

°

C

AUSTR ALIA:

30-year average (1961–1990)

WORLD:

30-year average (1961–1990)

Av e r a g e a n o m a l y (+/-) Average anomaly

Australian Rainfall Deciles

1 January–31 December 2019

Source: BOM

Mean Temperature Deciles

1 January–31 December 2019

A CHANGE IN THE WEATHER

Figure 1

Figure 2 Figure 3