Sunday, July 25, 2010

2010: The Hottest Year in Recorded History

It's the hottest year in recorded history

Jul. 20, 2010

Anna Mehler Paperny and Patrick White

Around the globe, it is the summer of our sun-stricken discontent.

This week, the U.S. National Oceanic and Atmospheric Administration revealed that the Earth is on course for the hottest year since record-keeping began in 1880 – 0.7 degrees above the 20th-century average.

It is the sweltering outcome of a bizarre confluence of abnormal weather that has been swirling about the globe for months – in the process parching Thai crops, melting German roads, thwarting Canadian military operations and wreaking worldwide climatic havoc.

Throughout Canada, the heat has been far more pronounced than the global average. Temperatures from January onwards have been 3.9 degrees above average, shattering the previous record of 3.2 degrees set in 2006.

Much of the U.S. has cooked of late amid a series of heat waves as the jet stream – which divides cool northern air and warm southern air as it wraps around the globe – remains at an abnormally high latitude. High-pressure systems have formed to the south of the jet stream, preventing it from dropping south and creating a self-perpetuating heat dome.

The same phenomenon has scorched much of Russia and Europe, as Muscovites have taken to the streets in bikinis and more than 1,000 Russians have drowned in the last month trying to escape record temperatures.

Meanwhile, the interaction of a zone of low pressure northwest of the British Isles and high pressure around the Mediterranean is pushing hot air into Europe, said British weather service spokesman Barry Gromett.

Monsoon rains have been plentiful over the Indian Ocean, but they have not continued on to land, scorching the earth in South Asia.

Polar cold fronts that normally sweep north through South America from the South Pole have been stalled by weather blocks – competing atmospheric centrifuges that halt weather patterns in their tracks.

International climate experts are at a loss to explain why these local phenomena are happening all at once, even when they factor in multi-decade cycles caused by shifts in ocean currents and El Nino’s heat factor.

“What is causing that is very difficult to answer,” said Annamalai Hariharasubramanian, a meteorologist with the University of Hawaii. “Since this warming has been there on a very large spatial scale, and also persisting for a couple of months now … these long-term oscillations could contribute but it looks like it’s more than that.”

One variable is the ever-shrinking size of the world’s ice caps. In June, Arctic ice cover shrank to the smallest area observed since record-keeping began in 1979.

“Ice reflects sun and when you melt it, the Earth absorbs more heat, which causes further melt back, which causes more warming,” said Danny Harvey, a climate researcher at the University of Toronto. “So when you lose ice, it means we’re in big trouble.”

There are myriad effects from this global tale of sweat and sunburn. For South Asia’s farmers, the dry, hot weather could spell agricultural disaster. Across much of the Prairies, wave after wave of muggy, rain-laden systems from the southern U.S. has dumped a record amount of rain and then warmed the sodden region just enough to create a perfect mosquito incubator. Meanwhile, weather experts across Europe are making comparisons to the heat wave of 2003, when soaring temperatures contributed to the deaths of more than 25,000 people.

Still, some experts are more cautious about drawing conclusions as to the extent of the heat wave: Antonio Moura, director of Brazil’s National Institute of Meteorology, said that while much of South America has had an unusually warm, dry winter so far, that could change with an expected, if delayed, cold front.

“One has to be looking at it more carefully, without jumping so much on one side or another,” he said. “We have to be careful about providing information that the whole globe is catching on fire.”

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