lightblueline

Roger Harrabin,BBC News environment analyst (April 4, 2008) reports on the effects of a major 'la nina' in the Pacific Ocean. This part of a multi-year fluctuation, and it's cooling the planet this year. These types of short-term fluctuations have been built into the climate models, which are still predicting a longer-term warming trend. Still, it's good to be cool! (Unless you live in Wisconsin, which gets enough cool every winter).

Global warming 'dips this year'

Here is an excerpt:
"Global temperatures will drop slightly this year as a result of the cooling effect of the La Nina current in the Pacific, UN meteorologists have said.

The World Meteorological Organization's secretary-general, Michel Jarraud, told the BBC it was likely that La Nina would continue into the summer.

This would mean global temperatures have not risen since 1998, prompting some to question climate change theory.

But experts say we are still clearly in a long-term warming trend - and they forecast a new record high temperature within five years.

The WMO points out that the decade from 1998 to 2007 was the warmest on record. Since the beginning of the 20th Century, the global average surface temperature has risen by 0.74C.

Rises 'stalled'

La Nina and El Nino are two great natural Pacific currents whose effects are so huge they resonate round the world.

El Nino warms the planet when it happens; La Nina cools it. This year, the Pacific is in the grip of a powerful La Nina.

It has contributed to torrential rains in Australia and to some of the coldest temperatures in memory in snow-bound parts of China.

Mr Jarraud told the BBC that the effect was likely to continue into the summer, depressing temperatures globally by a fraction of a degree.

This would mean that temperatures have not risen globally since 1998 when El Nino warmed the world.

...

"La Nina is part of what we call 'variability'. There has always been and there will always be cooler and warmer years, but what is important for climate change is that the trend is up; the climate on average is warming even if there is a temporary cooling because of La Nina."