Friday, August 24, 2012

Australia puts the chill on hot July

Image: Global temperature anomalies for July 2012 - Courtesy of NASA Earth Observatory

July 2012 was the hottest month on record for the continental United States. The heat was also felt up into the Canadian prairies, the Arctic and northern Greenland, Northern Africa, Middle East, Central Europe, Russia, Ukraine and the Antarctic Peninsula. But the temperature record fell short due to a few places like Australia which experienced cold temperature anomalies.

It would have been the hottest month ever, based on global land and sea temperatures, except for a few places much cooler that brought down the global average so that it was only the 4th warmest month on record since accurate records started being kept in 1880. This follows Earth's fourth warmest June on record and the global land temperature record for warmest May.

So exactly where abouts was it cool? Cool temperature anomolies occurred in Alaska, Australia, southern South America and over much of Antarctica to drag down the global temperature average. Australia is coming out of it's wettest two year period in history that resulted from a very strong back to back La Nina. Across much of continental Australia temperatures have been cooler than average for the last 6 months.

Image: Temperature anomaly for July 2012 courtesy Bureau of Meteorology

It would be nice to argue it was the work of the carbon tax reducing Australia's emissions, but the tax on large polluters only came into effect on 1st July 2012.

So are we Australians luxuriating in the below average temperatures? It would be nice to say we were, but cold extremes also pose risks for health, particularly in vulnerable people: the elderly, homeless and young children.

Image: Temperature anomaly for 6 months January-July 2012 courtesy Bureau of Meteorology

Indeed. Unusual Cold snaps can pose a significant risk to health as Roger Jones discusses on his blog in the article Perth morgues are full and SW WA has been unseasonally cold – coincidence?. In the article he discusses the impact of unseasonal cold weather, relatively speaking, experienced in Perth and the south west in June and July and ponders whether that caused all the mortuaries to fill.

"Contrasts in temperature are the largest risk to vulnerable people, rather than absolute temperatures themselves." Jones concludes.

The El Nino Southern Oscillation is moving into a neutral phase at present. When the next El Nino occurrs, it will bring warmer weather, increased drought and a boost to higher temperatures, and a good likelihood some more record temperatures will be set on a global basis.

Is it getting too hot for you yet?