Unseasonably Warm Weather A Clear Sign Of Climate Change, Say Scientists

The Guardian - Michael Slezak

El Niño driving current spike in warm weather and May almost certain to be warmer than average from 1961 to 1990

The sun rises over Port Philip Bay in Melbourne. Blair Trewin from the Bureau of Meteorology said the unseasonal weather was happening against a background of global warming. Photograph: Tracey Nearmy/AAP

Unseasonably warm weather across Australia, which is set to continue through the coming month, might be putting a spring in people's step but is a clear sign of dangerous climate change, according climate scientists and meteorologists. Australia and the rest of the world have been reeling from a string of temperature records being smashed. February caused alarm when it was the most unusually warm month on record by a huge margin. But that record was broken immediately by March.
In Australia March 2016 was the warmest March on record. And this week the Bureau Of Meteorology released its seasonal outlook, showing above average temperatures are set to continue across the country at least throughout May.
According to David Karoly, a climate scientist from the University of Melbourne, climate change increased the chance of March breaking the temperature record in Australia by at least seven times.
xx"The previous record had about a one in 43-year chance due to natural climate variations alone but now occurs about one year in six in the present climate, that is already affected by human-caused climate change," he told Guardian Australia.
"It's evidence that climate change is already happening – and increasing the risks of hot extremes."
Blair Trewin from the Bureau of Meteorology said: "April won't be a record but it will be well above normal."
Throughout May temperatures across most of the country have an 80% chance of being warmer than the average from 1961 to 1990. By June and July most coastal regions will continue to have unusually warm weather, however temperatures will return to normal around central and southern Australia.
The current spike in warm weather is happening partly because of the monster El Niño that spread a pulse of warm water across the Pacific Ocean in 2015. That El Niño is dissipating, spreading the warmer water around Australia, raising temperatures.
But all that was happening on top of the background of global warming, Trewin said. He said that these days, in an El Niño year, the world tended to experience extreme temperatures and merely "above average" temperatures in other years. Only when a La Niña cooled the globe were there normal or slightly cool temperatures.

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