April 2007 Global Mean Temperature

2.3 degrees hotter than usual, but chill on the way

New Zealand sweltered through its hottest May since record-keeping began ... but the weather was hardly perfect, as some areas were drenched in more than double their usual rainfall.

Figures issued today by climate agency Niwa showed that May was 2.3C warmer than usual.

The average monthly temperature was 13.1C, a heat normally expected for April.

The previous hottest May, recorded in 2007, had a mean temperature of 12.4C.

Niwa's principal climate scientist, James Renwick, said the numbers were extraordinary and unusual.

"A monthly jump of two degrees is extremely unusual - it's a surprisingly big step up," he said.

"We've had a very strong La Nina event in the tropics since about August last year, which brings weather from the north over New Zealand and warmer air down from the sub-tropics."

Mr Renwick said the warm tropical air flow also caused the destructive storms and flooding which hit the Bay of Plenty at the end of April.

"The warmer the air, the more water it can carry, which is why the areas which were the warmest, like the eastern Bay of Plenty, also had more than double their average rainfall.

"So it's been very wet in a lot of places and very warm, but with not a lot of sunshine."

At the start of May, eastern areas of the North Island were battered by torrential rain and gale force winds which caused widespread flooding and a state of emergency in Hawkes Bay.

Later in the month, Nelson's rivers were pushed to bursting point when the region had 3.5 times its normal rainfall. But its temperature was 3.5C warmer than normal.

At Whakatane, the airport raingauge showed the region had 2.5 times its normal rainfall.

Mr Renwick said the La Nina event, which was responsible for the record-high temperature, also caused the tornado which tore through Auckland's North Shore at the start of the month, killing a man at Albany.

"To get a vigorous tornado, you've got to get a vigorous thunderstorm," said Mr Renwick.

"And for that to happen you've got to have a lot of moisture in the air and energy."

He said global warming had increased New Zealand's average temperature by about 1C in the past hundred years, so other heat records were becoming more and more likely.

"It makes it easier to get a warm month because the background temperature keeps increasing."

But the warmth was unlikely to last until the long Queen's Birthday weekend, as a low pressure system would move south later in the week.

Isn't AGW just a guess? | Avian Influenza (Bird Flu) Blog

No, it’s a theory. They use the theory to guide development of models, from which come predictions. A lot of those predictions are very accurate (e.g., polar amplification, ice ages caused by Milankovitch Cycles, Snowball Earth).

Have the skeptic models been more accurate? I can’t find any skeptic predictions, maybe you could tell us.

Answer by Stone Cold It Is All B.S. There is no such thing as Global warming it is just a stunt to get consumers to buy products they normally wouldn’t have. the truth is this was all started by G.E. they had a big thing about it on Sat. TV the U.S. government is launching an investigation on it soon. the fact is the earth’s overall temperature is dropping

Answer by J S No, the measured increases are confirmed from multiple data sources:

http://www.columbia.edu/~jeh1/mailings/20080303_ColdWeather.pdf

The loss of polar ice was an issue that made 2007 surprisingly warm (tied for second warmest year) in spite of the strong La Nina cooling influence. Look for that to be a particularly strong influence angain in 2009 or 2010 when El Nino returns.

We don’t have record cold and snows globally, and you’re talking about a weather event, not a long term climate trend.

About hurricanes, your point about 2005 is correct: The year 2005 globally was the hottest year on record, so it’s not surprising that in that one year there were more category 5 hurrcanes than in most prior decades.

I don’t know about the Southeast US, but the Rockies and the Sierras are documented as affected by global warming, and Lake Mead behind Hoover Dam is halfway to becoming unusable (in the 2014 to 2021 timeframe).

I don’t beleive that anyone said that SARS and Avian Flu would cause pandemics because of global warming. I think you’re making that up.

So you’d have to ignore the 2007 temperature, represent one season of cold weather as climate, cherry-pick local drought data (from one weather season), ignore the correlation between 2005 temps and 2005 hurricanes, and try to connect SARS with global warming to make the claim that somehow you were making a point about global warming.

Answer by BB It’s called a theory.

I also have a theory. Jello has no clue. That’s why he’s here on Y/A instead of publishing research papers in a scientific journal. Please, do us all a favor and go teach the ignorant PhD’s at NASA, National Academy of Sciences, American Geophysical Union, and every other respected science organization around the world a lesson.

World Economic Outlook, April 2008, Housing and the Business Cycle

Climate law in Australia

The Polish Climate in the European Context, An Historical Overview

Parliamentary Assembly, Working Papers, 2007 Ordinary Session, Second Part 16-20 April 2007

Climate change 2007, the physical science basis : contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change