Human hands across the globe switch up the heat

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 35C, breaking records for the hottest start to this month, while Sydney and Adelaide have had a string of days over 30C.

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.