As the northern hemisphere slides into winter the southern hemisphere is sliding into summer or, in the case of Australia, diving into summer. On 6 October, Melbourne hit 35°C, breaking records for the hottest start to this month, while Sydney and Adelaide have had a string of days over 30°C.
But for Australians this record-breaking heat is starting to become familiar. A study, published in the journal Geophysical Research Letters , shows that since 2000 hot record-breaking events on average have outnumbered cold record-breaking events by 12 to one. Climate simulations show this imbalance would not occur under natural climate variability, and that human-caused warming is behind the plethora of hot records.
The soaring temperatures, combined with parched soil and dry vegetation (much of east Australia, the west coast and Tasmania have had significantly below average rainfall over the last 10 years) have made Australia a tinderbox.
Even if it does rain now the dry state of the ground will make it hard for that moisture to be retained. This year the problem is being amplified by the extra strong “Godzilla El Niño” conditions in the Pacific, associated with reduced rainfall and warmer temperatures in Australia. Already Australia has had its third driest September on record; so far October has been drier than average too.
Satellite maps show flames licking dozens of locations, and already serious bush fires have taken hold. Rather than relaxing in the seasonal warmth, Australians are on the look-out for the smallest thread of smoke. It’s a tense time.
