Sea temperatures around Australia are posting "amazing" records that climate specialists say signal global records set in 2014 may be broken this year and next.
March sea-surface temperatures in the Coral Sea region off Queensland broke the previous high by 0.12 degrees – a big jump for oceans that are typically more thermally stable than land. Temperatures for the entire Australian ocean region also set new highs for the month, the Bureau of Meteorology said.
"This is a pattern we've seen really since 1993 or even longer," Dr Braganza said.
For the Coral Sea region – which includes the entire Great Barrier Reef and stretches from Cape York almost as far south as Brisbane – sea-surface temperatures from January to March were 0.73 degrees above average at 29.16 degrees, making it the warmest three-month period on record, the bureau said.
The unusual warmth off Australia comes as the Pacific Ocean remains primed for an El Nino event, as the bureau reported last month.
If such an event occurs, the underlying warming from climate change will get a further boost from natural variability, making 2014's ranking as the hottest year on records going back to the 1880s likely to be short-lived, according to Andy Pitman, head of climate research at the University of NSW.
"If we do get an intense El Nino, it will blitz the records," Professor Pitman said. "The climate is on a performance-enhancing drug and that drug is carbon dioxide."
A warm 2015 is very likely, particularly given the El Nino-like conditions in the Pacific, which will provide a significant backdrop to climate change negotiations for a new international treaty in Paris late this year, Professor Pitman said.
"If governments turn up in Paris after a series of major climate events, the foundation of their discussions...would be somewhat different than if they turned up in a period of benign climate," he said.
El Nino outlook
The bureau is due to update its El Nino forecast on Tuesday. At the end of March, it rated the chance of such an event this year at 50:50, while United States agencies are tipping the likelihood as 70 per cent.
El Ninos typically result in drier and hotter than usual conditions for eastern Australia as rainfall patterns shift eastwards away from the continent. Such an event would be bad news for inland regions of Queensland and NSW which have just had their third "patchy" monsoon in a row, with poor summer rains for many areas, Dr Braganza said.
"The models are really strongly suggesting that we will get an [El Nino] event by mid-year," he said.
Nathan Bindoff, a professor of physical oceanography at the University of Tasmania and a contributing lead author to the past two Intergovernmental Panel on Climate Change assessment reports, said the abnormal warmth across northern Australia was a typical precursor of an El Nino.
The March temperature reading for the Coral Sea "was a bit of a blinder", Professor Bindoff said.
"The global maps of sea-surface temperatures show a very similar picture of a rising trend," Professor Bindoff said, adding that some areas off the Australian coast are rising at two or three times the worldwide average.
Waters in the Northern Tropics region of Australia also set record temperatures in March.
"I expect it to get warmer and it will be the end of the warming pause debate," Professor Bindoff said. "Records will be broken steadily."