Friday, September 18, 2009

A hot August, on average, but not everywhere

This summer's global temperatures were warm, in spite of what you may hear on the news.

“The world’s ocean surface temperature was the warmest for any August on record, and the warmest on record averaged for any June-August,” NOAA reported this week.

(Image: Global climate anomalies for August 2009, compared to a baseline average global temperature for August from 1961-1990. Where it's blue, temperatures were cooler than normal; where red, warmer. Source: NOAA)

It's not what you may have heard, because climate isn't consistent around the globe, and in fact, this summer, it was pretty cool in a few places. Notably, central North America, Eastern Europe and the Japan area.

There has been a fair amount of press on the comparatively cool summer in much of the U.S. Mainland.

But trying to assert global conditions from regional patterns is as difficult as a blind man trying to describe an elephant when he can only touch the tail.

Other areas of the world were way hotter than usual. Australia is the prime example. But also west Greenland, Peru, western Europe.

Hawai'i did not appear to have either exceedingly hot nor exceedingly cold temperature anomalies.

But ocean temperatures globally were a full degree Fahrenheit warmer than the 20th century average for the same time of the year, NOAA said.

And the summer warming is part of a warm trend that appears to be ready to cover the whole year, the NOAA report said: “For the year to date, the combined global land and ocean surface temperature of 58.3 degrees F tied with 2003 for the fifth-warmest January-August period on record. This value is 0.99 degree F above the 20th century average.”

Do these data points prove anything with regard to the larger issue of climate change? No. It's a warm year. Doesn't prove anything by itself, although as part of a larger trend, it can suggest things. But that's another story for another time.

© Jan TenBruggencate 2009

1 comment:

cbuddenhagen said...

Still scientists help with their communication of results:

"The world leaders who are meeting at the United Nations to discuss climate change on Tuesday are faced with an intricate challenge: building momentum for an international climate treaty at a time when global temperatures have been stable for a decade and may even drop in the next few years.

The plateau in temperatures has been seized upon by skeptics as evidence that the threat of global warming is overblown. And some climate experts worry that it could hamper treaty negotiations and slow the progress of legislation to curb carbon dioxide emissions in the United States."